Showing posts with label chocolate. Show all posts
Showing posts with label chocolate. Show all posts

17 Dec 2019

Smaken av servise

Oppsummering av matverksted 12/2019

Siste matverksted i desember var annonsert å handle om sjokolademousse. Joda, vi hadde en systematisk smaking der vi skulle gi tilbakemelding på smaksopplevelsen av to porsjoner sjokolademousse. Saken var bare at det var nøyaktig samme sjokolademousse i begge porsjonene; eneste forskjell på de to var at de var servert fra skåler med ulik fasong.

Lureri? Både ja og nei, men som arrangør følte jeg nok litt på dårlig samvittighet når jeg inviterte til matverksted med tema sjokolademousse, men der det egentlige formålet var å undersøke et annet aspekt enn selve moussen. Nemlig effekten av visuelle stimuli, i dette tilfellet former, på smaksopplevelse. Som kompensasjon for "Lureriet" brukte vi siste del av sesjonen til å lage og smake på en variant av sjokolademousse basert på kun sjokolade og vann, nemlig Hervé This sin sjokolade-chantilly som jeg har skrevet en del om tidligere (inkludert oppskrifter): Chocolate chantilly del 1 (hvit sjokolade), del 2 (melkesjokolade) og del 3 (mørk sjokolade).

Hvorfor servere samme dessert fra to ulike skåler?

Anu Hopia og Tatu Lehtovaara, som gjennomfører sine parallelle "søster-matverksteder" i Helsingfors, tok initiativ til dette temaet etter inspirasjon fra en forskningsartikkel av Harrar og Spence (2013) i tidsskriftet Flavour: "The taste of cutlery: how the taste of food is affected by the weight, size, shape, and colour of the cutlery used to eat it". Charles Spence har sammen med andre i sin forskergruppe i Oxford forsket mye på temaet kryssmodale koblinger (crossmodal correspondences), assosiasjoner vi gjør på tvers av sanser: Vi assosierer ofte rød farge med søt smak, i hvert fall i større grad enn gult eller grønt, lyse dissonerende toner knyttes av mange til sur smak, og en klassisk studie der respondentene ble bedt om å knytte henholdsvis ordene "kiki" og "bouba" til de to fasongene nedenfor:

Hvilken er "kiki" og hvilken er "bouba"? Les mer om det her.
(Ill.: Ronhjones @ wikimedia commons)
I artikkelen sin viser Harrar og Spence at opplevelsen av det man spiser, i deres tilfelle, yoghurt påvirkes av hvor tung skjeen man bruker er (respondentene opplevde yoghurten som tettere og mer eksklusiv når den ble spist av en lettere plastskje sammenlignet med en tyngre) og fargen på skjeen hadde også innvirkning på den opplevde smaken. Når respondentene fikk servert en ostebit fra hhv. kniv, gaffel, tannpirker og skje, ble osten rangert noe saltere servert med kniv enn med de andre tre. Når den britiske sjokoladeprodusenten Cadbury endret fasongen på en av sine melkesjokolader fra flat rektangulær til rund mottok de klager fra forbrukere som spurte hvorfor de hadde tilsatt mer sukker i sjokoladen. Sannheten var at oppskriften var nøyaktig den samme, det var bare fasongen som var endret! Altså assosierte forbrukerne rund form med søt smak, noe Spence har diskutert og knyttet til at kantete former i større grad assosieres med bitterhet mens rund fasong assosieres med søtt. Saken fikk også medieoppmerksomhet, bl.a. i The Guardian. Vi hadde altså lyst til å undersøke om form eller farge på bestikk, servise og slikt kan påvirke vår smaksopplevelse.

Forsøket

Våre finske venner valgte å undersøke effekten av bestikket, der de deltakerne spiste sjokolademousse med hhv. vanlig stålskje med glatt overflate og gullfarget skje med mer ru overflate. Siden Klippfiskakademiet, som var vertskap også denne gangen, har dessertskåler av samme størrelse men ulik fasong valgte vi å knytte forsøket vårt til skålens fasong og la skjeene være like.


Deltakerne fikk minimalt med informasjon ved ankomst, og vi var nøye med ordbruken for å forsøke å unngå å lede prøvesmakerne i en bestemt retning. Deltakerne ble delt i 5 + 6 der hver gruppe fikk smake mousse fra enten rund eller firkantet skål. Oppdraget deres var å streke under typiske karakteristiske assosiasjoner, smaker, usmaker og konsistenser som er relevante for sjokolade og mousse (se f.eks. her og her). Vi hentet inspirasjon fra en sensorisk metode som omtales som "check all that apply", CATA-metodikken og laget et skjema der deltakerne skulle streke under ord de syntes passet til smaksopplevelsen:

Ville deltakerne for eksempel oppleve moussen servert fra firkantede skåler som bitrere? I så fall kunne man tenke seg at flere som smakte fra firkentet skål streket under dette ordet enn de som smakte fra rund skål. Deltakerne ble så invitert til å bytte plass, uten at noe annet ble sagt, og smake nøyaktig samme mousse fra skål med annen fasong.

Resultatet

Et betydelig problem med undersøkelsen vår var det lave antallet respondenter: fem for den ene og 6 for den andre fasongen. De fikk anledning til å smake begge skåler, så i sum kan man si at vi hadde 11 resultater for hver av formene. Men vil regner andre runde som mindre gyldige resultater av (minst) to grunner:

  • deltakerne var allerede delvis mett etter første runde (ikke helt sant, da flere forsynte seg med en tredje porsjon etterpå; en stor kreditt til Klippfiskakademiets oppskrift og håndverk i å lage sjokolademousse)
  • deltakerne kunne ha gjettet, eller begynt å tenke, at det her var noe rart, lagt merke til formen på skålene eller annet; "begynt å tenke" framfor å respondere intuitivt

Resultatene denne gangen ble dessverre ikke særlig klare med hensyn til de ulike beskrivende ordene; det tegnet seg ikke noe bestemt mønster. Var vi for få respondenter og at det hadde blitt et tydeligere resultat om vi var flere? Kunne ordene som deltakerne skulle streke under vært bedre valgt? I samtalen i etterkant ga tre personer likevel tilbakemelding om at de fikk assosiasjoner til karamell først når de smakte fra den runde skåla, fem deltakere mente at den runde skåla ga en sterkere assosiasjon til kaffe, en rapporterte at mousse fra den firkantede skåla opplevdes mer kornete. Så kanskje fasongen likevel hadde innvirkning?

Et interessant bonus-resultat. Fatet startet med seks skåler av hver,
slik endte det etter at deltakerne fikk forsyne seg fritt av restene.

Ett artig resultat kom som en tilfeldighet.
Etter forsøket hadde vi ganske mye mousse til overs. Vi satt dette fram slik at de deltakerne som ville kunne forsyne seg med mer. Det var satt fram seks skåler av hver fasong, og når folk hadde forsynt seg var det tatt tre runde skåler og ingen firkantede. En fjerde person som av undertegnede hadde fått overrakt en rund skål sa at han hadde valgt rund framfor firkantet om han hadde valgt selv (derav 2 + 6 på bildet til høyre). Vår CATA-blindsmaking hadde jo ingen spørsmål om preferanse, kun beskrivende smaksord og assosiasjoner. Kan det være at deltakerne foretrakk sjokolademousse fra rund framfor firkantet skål? Kanskje er dette et halmstrå å klamre seg til når andre resultater ikke er så tydelige? Et annet halmstrå å klamre seg til er at mye av forskningen som gjøres ofte gir tvetydige svar, så det som faktisk ender opp med å bli publisert og som vi kan lese og høre om har ofte ganske tydelige funn å vise til. En litt lettvint generalisering, noe man skal være varsom med å gjøre, men kanskje noe å tenke over neste gang man velger å være skeptisk til kunnskap som bygger på forskningsresultater fra mange studier som peker i samme retning?

25 Dec 2010

New chocolate & dispersion article out in Norwegian school science periodical

A popsci article on chocolate truffles/ganache and dispersions recently published in the Norwegian school science periodical (print and web).

As a starting point for the text, I use a recipe for chocolate ganache from the Oslo chocolatier Deux chocolatiers. From there, I describe chocolate and ganache as dispersions and how we can understand the structure/texture of chocolate, why chocolate seizes and where chocolate ganache/truffles come into the picture. The article can be found at www.naturfag.no/mat:
Also, recommendable is Anu's blog molekyyligastronomia with two entries recently on chocolate ganache (look forward to the day comes that google translate deals efficiently with Finnish grammar, though).

To round off the season, Muppet Show's own gastronomical column headed by the Swedish chef making chocolate Moose must be one of the ultimate Christmas treats treat wrap up the fooducation blog before Christmas holidays :)



Some more posts on chocolate

6 Jun 2010

Foolproof chocolate Chantilly, part 3:3. Dark chocolate mousse w/orange


This is the third post on chocolate mousse; pure and clean
containing only chocolate and flavourings. The process is very straightforward, although this dark variety might be the most tricky one among the three published. However, 'tricky' is not really that tricky...

This post is the last on chocolate mousses for now: white-, milk- and dark chocolate. Previous posts are
Refer the two previous ones for discussions on the how's and why's on this way of making chocolate mousse. This time, I'll get to the point right away.

9 May 2010

Foolproof chocolate Chantilly, part 2:3. Earl Grey milk chocolate mousse with coffee/cocoa nibs

Numerous blogs, web sites and newspaper articles have picked up variations of the "molecular gastronomic recipe" for making chocolate mousse with only chocolate and water first presented by Hervé This. However, most these recipes tell you to try-and fail. I have for some time felt that there is a need for making this recipe foolproof. And on top of it all, it's quite straightforward to make as long as you're precise with the measurements.

This post is the second out of three on chocolate mousses: white-, milk- and dark chocolate. Part 1 was white chocolate mousse w/ginger. I've chosen to give recipes for mousses with added flavours rather than the pure ones. Hence, the recipe might not work out properly if other ingredients, or pure water, is used as liquid.

The main reason for doing these experiments is that most of the recipes on the "molecular gastronomic mousses" tell you to try and fail until you're satisfied. That's ok if you are to serve the mousse right away. However, the mousse will firm up upon storage, starting after 1-2 hours I want a recipe I can trust even when the mousse is kept in the fridge, not having to make it or, even worse, repair it while the guests are waiting.

Video shows texture of mousse after one night in the fridge made according
to recipe below. Also some microscope pictures of the same mousse

EARL GREY MILK CHOCOLATE MOUSSE/CHANTILLY
4 portions

25 Mar 2010

Foolproof chocolate Chantilly, part 1:3. White chocolate mousse with ginger

Numerous blogs, web sites and newspaper articles have picked up variations of the "molecular gastronomic recipe" for making chocolate mousse with only chocolate and water first presented by Hervé This. However, most these recipes tell you to try-and fail. I have for some time felt that there is a need for making this recipe foolproof.


This post is the first out of three on chocolate mousses: white-, milk- and dark chocolate. I've chosen to give recipes for mousses with added flavours rather than the pure ones. Hence, the recipe might not work out properly if other ingredients, or pure water, is used as liquid.

The main reason for doing these experiments is that most of the recipes on the "molecular gastronomic mousses" tell you to try and fail until you're satisfied. That's ok if you are to serve the mousse right away. However, the mousse will firm up upon storage, starting after 1-2 hours. I want a recipe I can trust even when the mousse is kept in the fridge, not having to make it or repair it while the guests are waiting.


Video shows texture of mousse after one night in the fridge made according to
recipe below. Also some microscope pictures of the same mousse





26 May 2009

Chocolate part 3:3 - making your own instant cocoa

During graduate studies, we often wished for a "journal of unsuccessful chemistry" for the benefit of all the failed experiments we do. What if there was a journal where we could look for the experiments we were planning, and see if someone else had tried it and failed? This is one of those stories.

Cocoa powder has this property that it is hardly wetted by water. The result is
  • when making cocoa, thorough agitation or stirring is necessary to avoid lumps and cocoa powder floating on top
  • eating plain cocoa powder is not a very pleasant experience
In my search for info on why chocolate seizes (chocolate part 1:3) and shaping chocolate (chocolate part 2:3), I came over three papers on the wetting properties of cocoa and cocoa granules. In short, they stated that if I could turn cocoa powder into a granulate rather than the fine powder it is, it might disperse more easily because it'll interact better with the water molecules. Also, I figured, it might taste better in it's dry state as it's easily wetted by the saliva in my mouth.

Would it be possible for me to make my own instant cocoa, or maybe some palatable cocoa powder for sprinkling on top of dishes? If so, I could make my own blend and use quality cocoa rather than the sugar-loaded mixtures that are sold in grocery shops.

Granulating cocoa powder
Omobuwajo et al. brought about an easy method of making granules that are readily wetted by water. They simply heated the cocoa powder on metal plates. No need for expensive industrial machinery and additives. They investigated the granulation related to various cocoa-to-sugar ratios and conclude that the two best instant cocoa mixes were made by rapid heating of sugar and cocoa in 3:1 and 4:1 ratios, using fine sugar (0.23 mm), giving granules of 0.18 mm size. Now, if heated metal plate = skillet on my stovetop, I might make my own instant cocoa powder, or...?

A mixture of 9 g plain cocoa powder and 27 g sugar was heated in a pan on medium high heat (a little below maximum) with continuous stirring for 5 minutes.

Result: yes, the cocoa is granulated (right). No, I was not able to make granules that disperse more easily in a reproducible manner (some times it was easily wetted, sometimes it wasn't). Also, the powder tasted somewhat different due to the heat treatment (surprise...), without being more palatable than pure cocoa powder mixed with sugar.

Conclusion: more testing is necessary, several parameters to vary (temperature, time, stirring). This might probably work, but I don't find this interesting enough to spend more time on experimenting.


Wetting properties of cocoa powder
Wetting by water is closely related to whether something is hydrophilic or hydrophobic. If it's hydrophilic, it loves water and wetting occurs easily; water spreads out on the surface. If it's hydrophobic, the opposite occurs, such as on Gore-Tex. Wetting is not limited to water, and other solvents also possess wetting properties. These properties are in turn closely related to the surface energy. A general rule is that media/material with similar surface energies will possess similar wetting properties.

Galet et al. reported that the surface energy of cocoa powder is considerably lower than surface tension of water. Result: water and cocoa powder don't mix very well (surprise...). The bad dispersion behaviour of cocoa is caused by a number of phenomena, and one is the hydrophobic nature of cocoa, the fat content being 10–12% in cocoa powder. The mean particle size of cocoa is commonly around 16 micrometres (0.016 mm), but the size distribution is wide. The smaller the grains, the more difficult is the dispersion. Granulating the powder (making grains of 0.02 mm - 2 mm) resulted in enhanced wetting properties.

Partly, the bad dispersion properties is because of the bad flowability and the cohesive forces of the powder. The cohesion results in solid agglomerates, and the shear forces are not sufficient to break the cohesive forces between the grains. In plain words: cocoa powder lumps up in water, simply floating on top (another surprise...).

Cocoa powder in alcohol
A conclusion that may be drawn by this, is that liquids with lower surface tension (surface energy) than water might wet cocoa more easily. Galet concludes that liquids with lower surface energies than 40 mN/m will wet the cocoa powder, and that less than 15 mN/m will give perfect wetting. Water has surface energy 72 mN/m, not to wonder why cocoa powder and water doesn't mix well. However, alcohol (ethanol) has surface energy 22 mN/m, and a 40% ethanol in water mixture has surface energy 41 mN/m.





Conclusion: making cocoa flavoured alcoholic drinks should be easier than water-based ones.



References
Galet et al. "Improving the Dispersion Kinetics of a Cocoa Powder by Size Enlargement". Powder Tech. 2003, 130, 400-406.

Galet et al. "The Wetting Behaviour and Dispersion Rate of Cocoa Powder in Water". Food Bioprod. Proc. 2004, 82, 298-303.

Omobuwajo et al. "Thermal Agglomeration of Chocolate Drink Powder". J. Food. Eng. 2000, 46, 73-81.

On chocolate for education purposes:
http://www.exploratorium.edu/chocolate

http://expertvoices.nsdl.org/connectingnews/2009/02/04/the-science-of-chocolate-just-in-time-for-valentines-day

9 Apr 2009

Chocolate part 2:3 - shaping chocolate with a meat grinder

Peter Barham writes that chocolate is shear-thinning; it becomes fluid when shear stress is applied to it, such as by a meat grinder. I went on grinding...

A shear thinning, or pseudoplastic, medium is one that exhibits decreased viscosity when shear stress is applied. The most common example is probably ketchup. Turn the bottle upside down, and the contents stay put. Give the bottle a knock, and annoyingly half the bottle pours out. The same phenomenon is in action when a great landslide results from just a small shaking (i.e. quake) when the area resides on clay ground. Paints also rely on this phenomenon: they are runny when brushed or rolled, but become viscous as soon as the pressure is removed, and thus don't run down the wall.

Following Peter Barham's idea, I had another look in Beckett's "Science of chocolate", which confirmed that chocolate is shear thinning (I suspect that Barham indeed refers to Beckett). In addition, when the softened chocolate firms up again, after just a few seconds, it recrystallises in the same crystal form as before. This is important, because heating-cooling sequences (such as when melting melting) might lead to blooming, such as fat bloom.

My idea was hence: is it possible to use this property to shape chocolate and still avoid the need for apparently laborious and complicated tempering?

My only available equipment for applying shear stress on such a hard medium as chocolate was our kitchen machine with the meat grinder/mincer attached. Running the chocolate through this grinder, the result was what I've termed "chocolate twigs":



Comments on the result
I'm fairly content with the result, but my detailed knowledge of crafting chocolate isn't good enough for me to do a proper evaluation. Even though the texture seems fine, still a nice snap when braking, the colour and surface structure is changed. Maybe that's just OK? However, there are some relevant points to consider:

- The point is applying shear pressure, and not melting the chocolate
  • 55% dark chocolate worked fine, whereas milk chocolate softens too much in the grinder (becomes pasty)
  • the metal grinder needs to be kept cool, since grinding generates heat and might melt the chocolate. Cooling can be done by wrapping a cold moist cloth around the grinder
  • the chocolate was kept at room temperature overnight (20-25 °C), but taking the chocolate directly from the fridge did also work (in a previous experiment)
- Amount of chocolate
You need quite a lot of chocolate to produce a moderate amount of twigs. In the video above, I spent 400 g. However, the chocolate may be run several times through the grinder. The rest is of course perfectly OK for making other chocolate-based stuff, or maybe practice tempering chocolate...

Coarse or fine mincing screens?
The coarse screen (8 mm holes) was the only one that worked in my hands, as the finer ones resulted in too much resistance. Too much resistance results in clogging and eventually warming/melting the chocolate.

Equipment
Our Kenwood Major (800 W) did the job, but I felt that I overloaded it slightly, especially when it clogged. Dark chocolate is really hard stuff. It'd been fun having some professional extrusion equipment with enough power and temperature regulation allowing to make various shapes. Barham mentions using a pasta machine for "shear shaping" chocolate, but I doubt it'll be strong enough to shape the chocolate, rather than crumble it. Maybe it'll work with milk chocolate?

References
I didn't find any directly relevant scientific literature on this, and the two only references I've found mentioning this (briefly) are

Barham: "The science of cooking"
Beckett: "The science of chocolate"

Also, Corriher's "Cookwise" has quite a lot of information on dealing with chocolate (again, I've still not got my hands on a copy of Bakewise, unfortunately)

15 Mar 2009

Chocolate part 1:3 - why it seizes with just a little water, ...and what to do about it

Revised June 2nd 2015 

(Important: See the last set of comments for a critique which possibly requires some major revision to the text and figures).

If just a little amount of water finds its way into melting chocolate, it goes all grainy and solid - it seizes/curdles. There is really no fix to the problem. However, if some more water is added, the chocolate suddenly becomes fluid again. How come?

In three recent posts in the Swedish food blog Matmolekyler ("Food molecules"), Malin discusses the physics of chocolate. In the third one, the question arose on what really happens when a little water makes the chocolate go all grainy, and why adding some more water solves the problem. It made me start looking around in my "standard" food literature base: Corriher, McGee, Belitz/Grosch/Shieberle, Barham, Pedersen, Dahlgren. Although Corriher came closest, none of them had the answer to Malin's question: "is there an oil-in-water emulsion going on or something?". Finally, Beckett did have the answer, maybe not very surprising, since the name of the book is "The Science of Chocolate". However, it took some serious searching even in this book in addition to a few research papers. Hence, I expect to write a couple of more posts on chocolate since I've dug into the topic.

Chocolate seems like no easy medium to work with, and according to books on the topic I have to follow loads of specific directions in order to avoid failing. I've postponed it in fear of failing. The solution to the problem: start by failing on purpose!

The problem
It all starts when trying to melt the chocolate. (Cook)books say:
  1. the chocolate should be carved or cut into small pieces
  2. use low heat, preferably a water bath or double boiler , stirring continuously
  3. don't ever get water in the chocolate (either from the water bath or from moist equipment)
  4. (microwave oven might be used as an alternative, although carefully)

I have an inherent need of doing things as easy as possible, and using the double boiler method makes me go nuts waiting for the last bits to melt. To me, water bath equals splashing warm tap water around in the kitchen sink. In that respect, points 2-3 pose a problem, because getting water in the chocolate results in this:

Left: 100 g melted pure (55%) chocolate
Right: the same melted chocolate after adding less than a teaspoon of water

In fact, so little water is needed for this to happen that steam from a boiling pan might be enough to make the chocolate go grainy. When this happens, there is no way back to the pure chocolate. However, it is perfectly usable for other purposes such as chocolate sauce, ganache, drinking cocoa etc. Alternatives to using water bath or a double boiler principle. In stead of water bath or double boiler, I usually use the microwave or even melt the chocolate directly in the pot using low heat and stirring continuously (have to be very careful). However, I love sabotage experiments. When recipes tell me by all means not to do something, the little boy awakens and I go for it. And that's the point in this post: what happens when chocolate seizes?

To understand what happens one need to know what chocolate is...

Basically, chocolate is
  • cocoa fat (cocoa butter) - water repelling
  • sugar particles - water loving
  • cocoa particles - somewhat unclear*
  • lecithin emulsifier - water repelling and water loving
  • (for milk chocolate: milk fat and/or milk powder)
Chocolate is a dispersion, consisting of solids distributed in a fatty (continuous) phase. It contains miniscule cocoa particles (mean diameter ca. 0.016 mm) and sugar particles too small for our tongue to notice them as grainy when properly distributed. The sugar is hydrophilic (water loving), and repelled by the fat. An important function of the lecithin emulsifier is to build protecting layers around the sugar particles so that they don't separate from the fatty phase and give a grainy texture. The emulsifier is commonly lecithin (lecithin is also a natural constituent of egg yolk, and the main reason for why the yolk doesn't split into a fatty and a watery phase).

Schematic drawing of the above photos
Left: pure chocolate. Right: chocolate after adding just a little water

What happens when water gets into the chocolate?
In it's solid form, pure chocolate is a relatively stable system virtually free of water (0.5-1.5% by weight). When the chocolate is melted, the stable dispersion is challenged. If just a small amount of water (or steam) finds its way into the chocolate, the water molecules form droplets, since they don't want to mingle with the fat. Since water and sugar like to mingle, the sugar particles are wetted by the water. The result is "the sugar bowl effect", just as when a few drops of water are spilled into a sugar bowl. The tiny sugar particles in the chocolate become moist and cling together giving larger lumps (agglomerates). The result is an inhomogeneous mixture between these sugar agglomerates and the cocoa fat mixture. These won't mix evenly because the sugar has gone watery (the lecithin is probably not capable of stabilising such large amounts of hydrophilic constituents). Since sugar is a major ingredient in chocolate, it all goes grainy. A water content of 3-4% by weight is enough to make the chocolate seize. Since the chocolate might contain som water already the critical amount of added water might be as low as 1.5% by weight (1/3 teaspoon on 100 g, ref. Afoakwa et al.).

Add some more water, and everything is "fine" again
If the chocolate has seized, there is really no way back to the original chocolate. However, if some more water is added, the grainy mass magically turns silky smooth again. What happens is that the emulsion inverts; whereas fat was the continuous phase in chocolate, now water is the continuous phase and the fat is distributed/"dissolved" in the water:
Left: 100 g melted pure (55%) chocolate, seized with less than a teaspoon water
Right: the same chocolate after a tablespoon of water

A definite explanation of this was in fact rather difficult to find, and the only literature source stating this explicitly was in fact Beckett's book (The Science of Chocolate. Afoakwe also states this, but refers to Beckett's book). He writes that about 20% by weight water vs. chocolate is needed to achieve such a phase inversion, whereas Corriher writes that you need a minimum of 1 tablespoon water per 56 g (2 oz) chocolate. This roughly equals 30% 20% by weight. Note that this is total amount of water; if cream, butter or some other water-containing ingredient is used, this contribution counts.

Schematic drawing of the above photos
Left: seized chocolate. Right: after adding a tablespoon of water

Since chocolate contain plenty of emulsifiers, this emulsion might be quite stable and a good starting point to many wondrous things such as drinking cocoa, chocolate sauce, ganache/truffles, foam/mousse ("chocolate chantilly") or even a chocolate mayonnaise.

What might be taught/learned
  • dispersions: emulsions and solid dispersions
  • solutions/solubility, hydrophilic and hydrophobic properties
  • experimental and cooking skills (dealing with chocolate)
  • observational skills (what to look for in an experiment)


*Note: Some sources (Rowat et al., 2011, and these ppt slides by Naveen Sinha) state that the cocoa particles are hydrophilic (water loving) and that the emulsifier surrounds these rather than (or just as much) as the sugar particles. I have not been able to confirm this and have thus drawn it as neither water loving or water repelling. However, I've found a couple of papers stating that the cocoa particles in fact contain fat (points towards water repelling, see Do et al., 2011) and that the emulsifier primarily attaches itself to the sugar particles (Vernier cited in Svanberg et al., 2011).


References, scientific papers

Afoakwa, Paterson & Fowler: "Factors influencing rheological and textural qualities in chocolate - a review". Trends Food Sci. Tech., 2007, 290-298.
Do, Vieira, Hargreaves, Mitchell & Wolf: "Structural characteristics of cocoa particles and their effect on the viscosity of reduced fat chocolate". LWT - Food Sci. Tech., 2011, 44, 1207-1211.
Rowat, Hollar, Stone & Rosenberg: "The Science of Chocolate: Interactive Activities on Phase Transitions, Emulsification, and Nucleation". J. Chem. Ed.201188, 29-33
Svanberg, Ahrné, Lorén & Windhab: "Effect of sugar, cocoa particles and lecithin on cocoa butter crystallisation in seeded and non-seeded chocolate model systems". J. Food Eng.2011104, 70-80.

References, books with relevant information on the subject

Beckett: The Science of Chocolate (1. ed.). Cambridge : Royal Society of Chemistry 2000.
Belitz, Grosch & Schieberle: Food Chemistry (3. ed.). Berlin: Springer 2004.
Dahlgren, Ö.: Laga mat - hur man gör och varför. Stockholm : Liber utbildning, 1994.
McGee, H.: McGee on Food and Cooking. London: Hodder and Stoughton 2004.
Corriher, S.: Cookwise. New York: William Morrow 1997.
Pedersen, T.: Kemien bag gastronomien. Copenhagen: Nyt Nordisk Forlag 2005.

23 Feb 2009

Matching cold smoked salmon & dark chocolate (TGRWT #15)

The ingredients to match in round no. 15 of "They go really well together" are cold smoked salmon and dark chocolate, and the round is hosted by Mex Mix. I thought I'd give it a go, and ended up with smoked salmon-goat's cheese-chocolate ganache-tortilla roll-ups/wraps.

I've attended "They go really well together" a few times now, and a description of what this flavour pairing relay is really about is given in the previous posts.

Cold smoked salmon wraps are quite popular starter or hors d'oeuvres in Norway, and is commonly made with spreadable goat's cheese. I thought this simple dish with its rather uncomplicated flavour might serve as a good basis for evaluating the salmon-chocolate combination. I wanted the chocolate to be spreadable and therefore made some ganache.

Some of the salmon here in Norway is made using juniper-flavoured smoke. Even though I could not find any match between smoked salmon and juniper berries on the foodpairing web site, this is an "accepted good combination". So I thought using juniper-flavoured cheese and chocolate might add a nice touch (although juniper berries of course are not equal to juniper smoke).

Basic chocolate ganache:
- 100 g dark chocolate (Odense 55%), chopped
- 100 ml double cream
- dried juniper berries, five chopped

The double cream was heated to the boil, the juniper berries were added and let to infuse for a couple of minutes. Chopped chocolate was added while stirring until fully melted. Left to cool, first in room temperature and then in the fridge for 1-2 hrs.

Smoked salmon-goat's cheese-chocolate ganache-tortilla roll-ups:
- Soft wheat flour tortilla
- Spreadable goat's cheese (chevre would probably work as well)
- Smoked salmon
- Rocket/argula

- Balsamic vinegar or lemon juice
- (gin)

The salmon was sliced thinly and brushed with gin and left in the fridge for 3-4 hrs (this made no noticeable difference, save your gin). Goat's cheese, ganache, salmon slices and rocket was spread on the tortilla. The tortillas were rolled and served with either balsamic vinegar or lemon juice for some acidity.

For cheese, I tried two different flavoured varieties: dill and juniper. Both worked, but I'd say that dill was a notch better, as juniper flavoured cheese together with juniper flavoured ganache and rocked gave a slightly too bitter overall experience.

Verdict:
There was no real crash in this dish. However, the salmon and chocolate didn't go up into a higher unity either. The roll-ups do just as well without the chocolate, and in my opinion this means that the chocolate is redundant. The juniper in the ganache was ok, adding a slight bitterness together with the rocket. The acid (balsamic vinegar or lemon juice on the side) was necessary to balance the flavours.

Two different cheese-to-ganache ratios were tested, depending on the area covered by cheese/ganache on the tortilla. Ca. 60:40 cheese:ganache resulted in the chocolate flavour dominating the cheese (but not the salmon). Using less ganache (ca. 80:20 cheese:choc) resulted in just a hint of chocolate.

By the way...
when first seeing this month's combination, my thoughts went to the wonderful comic character Gaston Lagaffe created by ingenious Belgian André Franquin (in Norway, Gaston goes by the name Viggo). Among Gaston's numerous distinctive features is his inherent need for experimenting with explosives and food, and often you wouldn't notice the difference. His favourite office-made dish is chocolate glazed herring (fresh or as kippers). To most of Gaston's readers, this probably sounds like a horrific combination, and I guess that was Franquin's motive. Such an irony then, that Franquin's countrymen at foodpairing.be now indicate that sardines and cocoa/chocolate might indeed be a good match!

Facsimile from a Norwegian Gaston album. Copyright probably the publisher Semic (Egmont), but believed being covered by fair use.

31 Dec 2008

TGRWT #13 roundup: caraway and cocoa

It's time to sum up the entered dishes for They go really well together #13. From the entries, it seems like caraway and cocoa/chocolate indeed do go well together.
However, for starters it should be mentioned that this combination has been discussed on khymos at several instances already. Also, I was made aware of the fact that pumpernickel contains both of these, see discussion and links at Medellitin.

What fascinates me with this month's entries is that you can literally build a whole multi-course meal on caraway and cocoa (in order of submission):




Caraway cocoa chili
by Brian at The Food Geek
[...] the chili turned out great, [...]all the flavors were balanced quite well. I could certainly taste the caraway, [...] and it definitely adds a new note to the chili. Probably some sesame would have rounded it out nicely.


Caraway chocolate cake
by M
[...] mixed 150 gram self raising flour, 1 tablespoon cocoa, 1 teaspoon caraway fruits, 1/4 teaspoon salt, 150 gram brown sugar, 75 gram walnuts, 75 gram pine nuts, 75 gram raisins and 75 gram chopped chocolate. I added 300 gram Turkish yoghurt, mixed everything gentle but thoroughly, spooned the mixture into a silicon cake pan and baked the cake in a preheated oven, 170 degrees Celsius, for about 75 minutes.

Caraway cocoa egg cream
by Rob at The Curious Blogquat
I was able to get the caraway flavor to stick with the chocolate [...] The chocolate is already subdued in an egg cream due to the seltzer, so it was nicely balanced with the caraway. We both enjoyed the drink and found it to be a nice pairing. [...] Interestingly I wouldn't do this combination again, but only because its a bit too "normal" for my liking. It was too good together, and not enough "wow" factor.

Chocolate cookies with caraway
by Martin at Khymos
In the stripped down version with only cocoa, caraway and some bitter lemon peel there you first notice the cocoa, then there is an aftertaste of caraway. I like caraway, so I was very pleased with the result. [...] Anyhow I think the 10:1 ratio of cocoa to caraway worked very fine. [...] With all the other spices present I wasn’t able to single out the caraway flavor, but it (probably) added to the overall complexity. I really recommend the recipe - even if you decide to omit caraway!


Chocolate-caraway mousse/caraway caramel tree surrounded by coconut water gelee pond, white chocolate-caraway-rye bread puree and dehydrated chocolate mousse rock (!)
by Larry at tri-2-cook
I like the flavor combo. It's not a powerful statement and it wasn't particularly easy to keep the caraway at the top of the flavor profile with the chocolate but they really do "go well together". Fun stuff.

Chocolate - caraway - peanut - Kumquat dessert
by Sølve at strezzafoods
I was quite happy with the result. A rich creamy dessert, and the caraway brought a spicy dimension that was both new but also very harmonious. The kumquat added much needed acid and bitterness. All in all a very different and amusing dessert, almost savory with nuts, spice, bitter chocolate and salt.


Beignets with Duck, caraway-chocolate and juniper sauce

by Alessio (alessiofangano [at] msn.com)

For 15 beignets:
15 Beignets
245 g Duck breast
40 g dark chocolate (60%)
1 tsp Caraway
100 g Butter
60 ml Red Wine like Shiraz
5 Juniper berries
½ tbsp Sugar
0.5 g Guar gum

Put the red wine with the juniper berries in a small saucepan and reduce over low heat with the lid on. When reduced of half, add the sugar and let simmer for some minutes. Strain trough a fine sieve and add guar gum while still warm. Brown butter on a skillet over medium fire. Strain and reserve. Grind caraway seeds in a mortar or spice grinder. Melt chocolate, caraway powder and 1 tsp of brown butter over a bain marie. Pour it on a shallow container so that the chocolate layer will be around 4mm thick. Let cool down at room temperature, unmold and cut into cubes. Refrigerate until ready to use. Take away the skin from the duck breast. Cut the meat in small dices. Render the duck skin in a warm skillet under a weight, drained the excess fat from time to time. Put the brown butter on a pan and when well warm, sauté rapidly the duck dices. Mix duck and chocolate dices in a bowl. Open in two the beignets, put in the lower part some of the duck chocolate mixture. Spoon over a teaspoon of the red wine sauce. Grind over some black pepper and close with the upper part and serve.

Verdict: When eating the beignet, the first aroma to be perceived is that of the juniper. The crunchiness of the beignet is followed by the juiciness of the duck meat and the barely melting chocolate with its caraway notes. In the whole the dish works very well, the tricky part is in the lightness of the beignet. The flavors come out very harmoniously and fulfilling. Chocolate and caraway are a perfect combination especially with red meat or game.


Chocolate sauerkraut
by Ole Eivind at Helt naturlig
As the sauce coated the cabbage shreds, the initial taste was very chocolatey with a nice caraway aftertaste. I could clearly taste that the two ingredients go really well together. The texture wasn't too bad either, but I wouldn't call the dish a success. The cabbage itself didn't work well, and for a dish consisting of little more, having the cabbage work against you can't be described as much other than a failure. It was an interesting failure however [...]

Almond-caraway coated chocolate truffles
by yours truly at fooducation
Firstly, a burst of crunchy, salt, roasted almonds followed by rich, dark chocolate. Second, while the chocolate melts and the cocoa flavour still dominates, the caraway comes through and lingers on together with the chocolate. [...] the chocolate and caraway work very well together.



Some comments on caraway aroma and flavour pairing with cocoa
Interestingly (at least to those of us with chemistry-oriented brains), the compound responsible for the intrinsic caraway aroma is (S)-carvone. The other stereoisomer, (R)-carvone, has a spearmint aroma. A striking example of the effect of chirality/handedness in chemistry: the two compounds are identical apart from the fact that they're mirror images, resulting in very different aromas.

(S)-carvone is also an important aroma component in dill seeds, and caraway is suggested to function as substitute for dill aroma (R. Zawirska-Wojtasiak: "Oils obtained from caraway and dill seeds are almost identical in composition").


(S)-carvone (left) has caraway aroma whereas (R)-carvone on the right smells of spearmint

Aroma components in caraway
Surprisingly, I could not find any literature reports on aroma components in caraway, but The Good Scents Company has listed aroma components for both caraway and chocolate/cocoa:

Aroma components in caraway
(S)-carvone
(Z)-carvone-5,6-oxide
(E)-carveol
(Z)-carveol
cuminyl alcohol
4-isopropyl-2-cyclohexenone
isobutyl angelate
3-hepten-2-one

Also, Flavornet has information on flavour components in caraway, only including carvone and carveol isomers, though. Compared to chocolate and cocoa, caraway seems to be a relatively uncomplicated mixture of aromatic substances. Is this possibly due to roasting of the cocoa beans resulting in very complex mixtures of aroma substances in these (from Maillard reactions etc.)?

I was quite surprised when I didn't find any direct matches between caraway and cocoa/chocolate. Maybe are any common substances in low concentrations? A caraway+cocoa google cross-search at The good Scents company returns a lot of hits, but none(?) with natural occurrence in both ingredients. The matches are mostly in the "odor and/or flavor blends with" category. This is of course uplifting, but gives no definite answers in terms of common components. If anyone can come up with such matches, I'd be happy to have a comment.

Finally, I can't resist taking a somewhat amusing detour by the 1927 Nature article Fluctuations in Affective Reactions to the Odour of Caraway Oil by J. H. Kenneth:

"Fluctuations in the affective reactions to caraway oil claimed attention [...the preference being] higher after lunch than that before. In the case of camphor, rosemary oil, menthol, sassafras oil, fennel oil, and a few other odours, no consistent fluctuations of this nature wore [sic] observed."

So, according to Nature, it's not indifferent what time of day you have your caraway. The paper also includes a plot of preference of caraway odour vs. time of day and moon phases :)

29 Dec 2008

Almond-caraway coated chocolate truffles

As a part of "They go really well together no. 13" (TGRWT #13), I wanted to try on making chocolate truffles. This was a first-timer for me, but I must (not very humbly) say that this time I had a lucky strike.

I think this might be the first time I've made something that gives me that experience you get when you go to a restaurant and they serve something you've never tasted before which leaves you both happy and amazed at the same time. Maybe for the first time, I felt that I'd produced such an experience. It's somewhat like the first time I was able to ride my bike without the support wheels.

Being a rookie in the field of confectionery, Shirley O'Corriher was my crutch (Cookwise, I haven't got around to buying Bakewise, yet). For basis recipe for chocolate truffles, I chose the "Smoothest-Ever Truffles" which worked well. Since I had already made salty almonds and caraway schnaps for Christmas, the table was laid.

Ingredients
5 egg yolks
300 g dark chocolate (70% cocoa, tried two different with similar results)
170 g milk chocolate ("lys kokesjokolade")
60 ml heavy cream
50 g butter (salted)
60 ml caraway schnaps
260 g salty almonds
13 g caraway seeds

Directions
1. Almonds were chopped in food processor and mixed with caraway seeds
2. Chocolate was finely chopped in food processor
3. Cream and egg yolks were heated gently in a pan, stirring constantly until slightly thickened. Butter added and stirred over low heat until melted. Chocolate added and stirred over low heat until melted. Stirred in the caraway schnaps
4. Left to cool in the pan (4-10 °C for a few hours or overnight)
5. Scooped up and made ca. 2-3 cm (1 in) diameter rough spheres. Rolled the spheres in my hands (warm hands make them melt slightly on the surface, helping ground almonds to stick)
6. Rolled in the ground almonds/caraway-mixture and left to cool


The experience
Firstly, a burst of crunchy, salt, roasted almonds followed by rich, dark chocolate. Second, while the chocolate melts and the cocoa flavour still dominates, the caraway comes through and lingers on together with the chocolate. Balance and contrast at the same time, both in flavour and texture, taking me through various phases of experience. Also, the chocolate and caraway work very well together.

The experience is different whether I let it melt in the mouth or if I chew it. Melting in the mouth gives a stepwise flavour experience since the caraway takes some time to come through. Chewing results in all the flavours coming out at the same time.

Comments
The size of the balls seem to make a difference. Too small, and all the tastes come out at once, and the amount of salt/almond/caraway is somewhat overpowering. Making them ca. 2-3 cm (1 in) diameter gives a creamy interior and a somewhat crunchy exterior which, to me, gives the best result.

The caraway schnaps does not seem to cut through the chocolate on its own, but gives that extra bite. I tried covering with cocoa powder rather than the almond/caraway mixture, resulting in no discernible caraway flavour. Hence, the caraway schnaps on its own does not give sufficient caraway flavour.

The amount of salt and caraway is of course a matter of taste preference. Some might want to reduce the amount of salt (i.e. use more lightly salted almonds), and caraway (less caraway vs. chopped almonds). To me the given amounts work well, though.

Reference
O’Corriher, S.: Cookwise. New York: William Morrow 1997.

4 Dec 2008

TGRWT #13: caraway and cocoa/chocolate

"They go really well together" round no. 13 is hereby announced. In taking on the task of hosting this somewhat sinister-sounding round, I thought a whiff of Christmas might be a proper safeguard, announcing caraway and cocoa/chocolate as flavour partners.

For newcomers: TGRWT (They Go Really Well Together) is a monthly(?) open invitation to come up with dishes that combine certain given ingredients that are supposed to match well. The hypothesis is that foods containing one or more common major volatile compound will work well in combination. The result of this might thus be a range of new and, sometimes unlikely, good combinations of ingredients. For further introductions to the topic, see the foodpairing web site and the introduction to the topic at khymos.


This is how you can participate in TGRWT #13:

1. Prepare a dish that combines chocolate and caraway. You can either
use an existing recipe (if there is any) or come up with your own.

2. Take a picture of the dish and write an entry in your blog by
January 1st with TGRWT #13 in the title. Readers will be particularly
interested in how the flavour pairing worked out, so make an attempt
at describing the taste and aroma and whether you liked it or not.

3. A round-up will be posted here (with pictures). Please send an
email to erik_at_fooducation.org with the following details: Your
name, URL of blog, URL of the TGRWT #13 post and a picture for your
entry in the round-up. If you don't have a blog, email me your name,
location, recipe and a brief description of how it worked out and I'll
be glad to include it in the final round-up.

Late addition: deadline 31. December

I'll have a look in the literature, and in the round-up I hope to be able to say something about what makes these two ingredients match, at least according to the favour pairing hypothesis.

30 May 2005

Book: The Science of Chocolate

I finished the book "The Science of Chocolate" yesterday night:



In my opinion, the book is ok for people with a certain scientific overview, but a little heavy on the industrial side to be very relevant to everyday molecular gastronomers (see future postings for definition). The experiments part in the last chapter is fascinating, but should have been elaborated further (experiments are described, but the expected outcome is up to the experimenter himself to find out). "Ideal for those studying food science" (from the synopsis) is probably correct, rather than for the science school teacher who wants to play around with food in the classroom (although some of the experiments probably are relevant and usable).

Erik

Post comment march 2009: The book has now come in a second, revised edition.