My first spherification

Yes, I know. I'm six years late to be among the cool guys, but who cares? To me it's all about having fun and learning, and then being late is no issue.

As far as I know, spherification and it's related methods were introduced by El Bulli chef Ferran Adrià et al. some time after the turn of century. I has got a lot of attention, and a You Tube search on the term gives quite a few hits on demonstrations of DIY spherification.

The phenomenon is based on using hydrocolloids, that is compounds that can generate gels, mostly with water but other media are also know (oils and alcohol mixtures, that is). A good place to start is Martin Lersch's hydrocolloid recipe collection "Texture". A number of different gelling agents are being used, the most common household substances being gelatin and fruit pectin, the latter often used when making jams and jellies.

In this case I got my hands on some sodium alginate that I wanted to play with. When a mixture containing sodium alginate comes in contact with a calcium solution, the alginate starts to cross-link and a gel is formed. In this case, dripping a alginate-containing solution into calcium chloride generates small beads that are gelatinous on the surface and liquid in the centre. Alginate is somewhat sensitive to the pH, and sodium citrate might be used as a buffer to stabilise the pH at ca. 4-5 (all this information is found in the Textures recipe collection).

Sodium alginate is a polymeric carbohydrate-like compound which is soluble in water. When it reacts with calcium ions, cross-links are formed giving large three dimensional webs that become viscous/gel-like and holds water.


Strawberry spheres in sparkling drink (for lava lamp effect)
(Sparkling Chardonnay or non alcoholic cider are both fine)

Equipment
(immersion) blender
scale (0.1 g precision is needed)
some general kitchenware
disposable plastic pipette (7 ml) or plastic syringe (10-20 ml)
(pH strips)

Ingredients
frozen and thawed strawberries, 200 g
sugar, 25 g
sodium alginate, 1.9 g
sodium citrate¹, 2 g
calcium chloride², 2.5-4 g
water, 500 ml
Sparkling Chardonnay or non-alcoholic drink (i.e. apple cider)

Procedure (see You Tube for informative demonstrations)
For template, the recipe for Melon cantaloupe caviar taken from El Bulli's texturas recipes: The strawberries were blended and mixed with the sugar. pH measured to be ca. 3 (somewhat uncertain since the berries gave some colour to the strips). Sodium citrate was added gradually, stopping at a total of 2 g to get a pH of ca. 4-5.¹ Sodium alginate was added and blended (the alginate partially turned into lumps; should have added the alginate to a small portion, mixed this, and then added the rest. Lots of blending did the trick). The mixture was strained through a sieve. For easier dripping (see below), the mixture was diluted 1:1 with water (the initial strawberry mixture was rather viscous, resulting in oblong or drop-shaped "caviars"). This would of course affect gelation, hence the amounts here are deduced on a try-and-fail basis.

Calcium chloride was dissolved in the water. The strawberry mixture was dripped into the calcium chloride solution, the drops forming small strawberry beads, and left for 1/2 to 1 minute.³ The beads were strained, rinsed in water and added to the sparkling wine or cider.

(Tri)sodium citrate functions as a buffer due to its three carboxylic acid functional groups.


Verdict
The strawberry beads/spheres/caviars tasted good, no detectable flavour from the matrix. Simply strawberry. While mixing, the strawberries turned somewhat greyish. Not surprising, since the colour is an anthocyanin pigment (anthocyanin colours are pH dependent, often bright red in acidic environment and more on the green/blue side in basic conditions).

The reason for using Chardonnay was simply that I found Chardonnay to match well with strawberries at the food pairing database, and that this might be a fun aperitif (although I would maybe not spend money on an expensive wine and then put strawberry in it).

What might be taught

• chemical reactions might occur between chemical compounds
• experimental and cooking skills (weighing exact amounts, diluting etc.)
• dispersions: gels (hydrocolloids) and macromolecules
• pH, acidity and buffers (citrate)
• density (the beads float up together with the CO₂ bubbles, and sink when the bubbles burst)

The procedure is somewhat complicated, and I'm glad I didn't bring the kids the first time. When the table was set, and the solutions were ready, the kids loved dripping the solution making beads. Now I've got some experience, and next time I'll bring them along from the beginning.

Notes/comments
¹ It was difficult to assess the pH correctly, and the amounts of sodium citrate suggested in the textures recipe collection did not (seemingly) have the desired effect. Hence, citrate was added until the desired pH, adding up to 2 g.

² The CaCl₂ must be dry/dehydrated. In my case, it had absorbed moisture from the air and gone all wet (quite hygroscopic). It was in left in shallow bowls in the oven at 150-200 °C stirring occasionally. A couple of hours later, a white crystalline/powdery salt was left.

³ Using 2.5 g CaCl₂ per 500 ml water and leaving the beads 30 seconds in the bath resulted in rather soft beads. Leaving them for one minute gave beads that were solid almost throughout. I wanted firmer beads with a soft interior. Increasing the concentration to 4 g CaCl₂ per 500 ml water did the trick: firm shell, and liquid interior when the beads were left in the bath for somewhat less than a minute.

References
McGee, H.: McGee on Food and Cooking. London: Hodder and Stoughton 2004.
Lersch, M.: Hydrocolloid recipe collection

Has the term "Molecular gastronomy" lost it's content?

The term Molecular gastronomy has been debated quite heavily the few last years, and several prominent chefs and writers have denounced the term. What's in a name?

An interesting post on the development and applications of molecular gastronomy (MG), both as a term, but also as a phenomenon at Martin's khymos. Most of the relevant links are found in that post as well. Also, many of the comments are relevant and interesting, making the post more complete.

Has MG reached a point of matureness in the sense that it might have some real impact on peoples cooking in general? As mentioned in Martin's post, it has already to a certain extent, such as sous-vide cooking. However, some of the more spectacular applications (foams, alginate spheres etc.) combined with misuse of the term in media has resulted in the term being discredited. In my opinion, the name is not the main thing (although its ok to avoid misunderstandings and establish a common ground languagewise as well). I'll continue using the term until a better alternative gets the main foothold.

"Iberico on window pane". Photo: Naturlegvis/Erlend Krumsvik

However, I'd be somewhat surprised if we don't see more of the results from MG/research reaching a general public soon. Hopefully, some of the "less spectacular" but more "relevant" or "useful" knowledge might hit the domestic kitchens in not too long. The real test for me is: is this knowledge so relevant to the everyday citizen that I should teach this to my preservice teacher students attending our Food & health courses? A few examples from the top of my head:

• Alginate/hydrocolloid spheres (specifically)? No
• Sous vide cooking? Yes if the focus lies on the method rather than specialty equipment
• Application of knowledge about maillard reactions? Yes/probably
  
• Application of knowledge about umami taste? Probably
• Dispersions in food and everyday life (two posts)? Yes
  

Among the more recent and interesting examples is the 2007 Mottram et al. (incl. Heston Blumenthal) article on tomato pulp being more rich on umami taste than the flesh (short RSC chemistryworld article free of charge). When dealing with tomatoes, many cookbooks and recipes tell you to remove the pulp and use the flesh of the tomato only. However, Mottram's results indicate that the pulp and seeds carry lots of wonderful umami taste, and hence it'd be a shame to throw that away. Heston Blumenthal demonstrates this in one of his BBC In search of perfection episodes, more specifically making tomato sauce in "The perfect hamburger" episode. Also, tomato sauce figures among the freely available Blumenthal BBC videos.

Many cookbook recipes might be rewritten just slightly to incorporate this knowledge, giving more flavourful dishes. Furthermore, this knowledge is something that the domestic cook might adopt rather easily. I'd be really happy to see something like this making it into the domestic kitchens around. In that case, MG (or whatever one prefers to call it) does indeed have had an impact.

References (not comprehensive)
Ubbink, J. et al.: "Molecular gastronomy: a food fad or science supporting innovative cuisine?", Trends in Food Science & Technology, 2008, 19, 372-382

Ubbink, J. et al.: "Molecular Gastronomy: A Food Fad or an Interface for Science-based Cooking?", Food Biophysics, 2008, 3, 1557-1866

Martin Lersch (khymos) on definitions of Molecular gastronomy

Kroger, M: "Editorial: What's All This We Hear about Molecular Gastronomy?", Comprehensive Reviews in Food Science and Food Safety, 2006, 5, 48 - 50.

This, H. :"Molecular gastronomy", Angewandte Chemie, 2002, 41, 83-88.

Thorvald Pedersen's recent book: "Molekylær gastronomi"

Thorvald Pedersen has been writing about food and cooking from a scientific perspective for years (mostly in Danish as far as I know), probably well before the term molecular gastronomy gained much attention.

Now he's published his third book on the subject and has dared to use the debated and, according to some, oft misunderstood and misused name Molecular gastronomy. In fact, Pedersen has suggested his own definition of the term, being different from Hervé This' and Harold McGee's:

• Pedersen: "The science of choosing, preparing and eating good food"
• This: "The scientific discipline that looks for the mechanisms of culinary transformations and processes, from a chemical and physical point of view"
• McGee (1 and 2): "The scientific study of deliciousness"
  

This debate has been running on the MG mailing list also, by the way.

Anyhow, the book has been out for a few months and I got it for present. I've always loved reading Pedersen because he's got this way of making everything warm and cosy, very Danish in a way (Danes seem to be far more relaxed and life-enjoying than us Norwegians, or Swedes for that sake). Reading his books and articles are almost like having one's grandfather telling stories. For that reason, I think Pedersen is even more enjoyable to read than This and McGee language-wise. He seems more relaxed somehow, maybe because he has nothing to prove, being a professor emeritus in chemistry.

The book is shorter than his previous books "Kemikeren i køkkenet" (Chemist in the Kitchen), a collection of his articles in the Danish magazine Dansk Kemi (Danish Chemistry) and "Kemien bag gastronomien" (The Chemistry Behind the Gastronomy) which is more of a textbook in food/cooking science or molecular gastronomy.


"Molekylær gastronomi" is divided based on short articles into two main parts (following the introduction):

• The preparations. Articles on various foods (not dishes); carrots, potatoes, onions, fish, meat. Each article has one or two recipes, mainly taken from classic(?) cookbooks , exemplifying the main point in the article
  
• The meal: starting off with an article on flavour and goes on to describing three meals of increasing complexity, from outdoor cooking during his time as boy scout, to a tasting menu at the fat duck
• Also, the book is scattered with 27 small boxes on various themes such as plant cell structure, starch, how to identify fresh fish, colours in food, viscosity etc.
  

In terms of what he writes, most of the results refer to McGee and a few other sources, including his regular food column in Dansk Kemi (the Danish research on gourmet salting for juicy and tender meat is especially interesting, and I've planned to write a post on this). Hence, if you've read McGee, there are not many new astounding discoveries.

One interesting thing is how he uses the tables of nutrients given the various foods. Most commonly people use such tables looking for amount of sugar, fat, whether a food contains gluten etc., that is health purposes. Pedersen however, uses this information for cooking purposes, and he gives the relative amounts of nutrients by dry weight as well. This is really useful, because various foods are easier to compare. One example is looking for amount of starch in different sorts of potatoes, which might have different percentage amount of water. Given values by dry weight makes it much easier to compare (there seems to be something wrong in the potato tables however, as the amount of nutrients add up to more than 100%).

In my opinion, the book is worth buying just for the sheer enjoyment of reading it. Also, I warmly recommend his food column "Kemikeren i køkkenet" in Dansk Kemi, mentioned above, freely downloadable (single pdf files).

Very easy odour adaptation experiment

Matmolekyler published last month an incredibly easy and straightforward experiment for illustrating the phenomenon of odour adaptation.

Adaptation is the phenomenon in which you stop noticing an odour/aroma when you've been subjected to it for a while. This is, amongst other, used as a motive for varying aroma components throughout a meal. Have a look at "Jullovsexperiment: Hacka ditt luktsinne" (Google translated version: "Christmas holiday experiment: Hack your sense of smell"). In this case, Malin Sandström, proposes to use coffee and cinnamon.

I'm on constant search for experiments that give personal experiences with food and science. In my eyes, the sheer ease of this experiment is maybe the greatest advantage, making it very acessable for anyone wanting to experiment with these phenomena.

Heston Blumenthal and Peter Barham have also described this in one of their Kitchen Chemistry episodes (Discovery channel):

"Our brains, it seems, respond much more to changes in which molecules are in the nose and mouth than they do to what is actually there, for example - if you chew a piece of gum, the flavour will disappear after a few minutes, as your brain gets "bored" by the aroma in the nose - but there is virtually no reduction in the amount of flavour molecules in the nose. However, if you simply change the input from your tongue, by, for example - taking a sip of sweetened water - the full flavour will be instantly restored"

Peter Barham (Discovery Channel)

What to teach/learn

• Gain experience with aroma and sense of smell
• Experience the phenomenon of adaptation
• (Experience that flavour experience is both taste and aroma)

Post-comment
I tested the experiment with our students and it worked perfectly! The student with the cinnamon even commented: "the odour fades away while I'm smelling it". Great fun. A colleague has been doing this experiment for several years using (synthetic) almond and rum essences. However, the intensities of these are somewhat uneven, and one swamps the other. Coffee and cinnamon works perfectly :)

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):

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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.

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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.

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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.

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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!

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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.

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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.

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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.

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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 [...]

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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.

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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 :)

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.

Salty roasted almonds and caraway schnaps

Christmas time is making your own stuff from the basics. This year brought, amongst other things, salty almonds and caraway schnaps (aquavit).

Salty roasted almonds

• ca. 1 l concentrated brine
• 0.5-1 kg almonds
  

A very approximate, but still fool proof, method: Make a concentrated brine by dissolving as much salt as possible in ca. 1 l boiling water (takes approx 500 g or so, maybe). Dump in almonds (0.5-1 kg), as much so that the almonds are just covered. Put on lid and leave cool/cold overnight. The lower the temperature, the saltier the almonds, I usually keep them on the porch in wintertime but the fridge works well. Next day, strain and spread on a baking tray with parchment. Roast in the oven, fan turned on, at 150 °C to taste (I usually prefer 15-20 minues).

Principles governing the crystallisation of salt on the almonds

• Rapid cooling gives small crystals. If you want larger salt crystals that crunch, cool slowly (start with placing in a warm room), and use less saturated brine.
• A lower end temperature results in precipitation of a larger proportion of the salt, probably giving saltier almonds. For less salty almonds, leave in warmer place to cool and/or strain earlier.
  

The good thing about these is that no fat is involved, avoiding greasy almonds. Also, the method allows for easy production of rather large amounts (0.5-1 kg at a time) with a minimum of labour.


Caraway schnaps (aquavit)
The caraway schnaps/aquavit/snaps is inevitable at many Norwegian Christmas dinners. Making one's own (in Norway and Denmark, the term would be "dram" or "krydderdram") is in fact rather easy. Although the flavour might not be as complex as the commercial ones (sherry cask aging is not an option in our home...), I believe that the ones you make at home might be more concentrated in the spice/herb flavour. The directions follow the recipe from Rolf Øvrum:

• 25 ml caraway seeds
• 50 + 450 ml 40% unflavoured alcohol/ethanol (80 proof)
  

Mix caraway seed and 50 ml ethanol in a lidded jar and leave in room temperature for 5-6 days to extract (longer storage times results, according to the literature, in unpleasant turpentine-like flavour). Make sure that the jar is perfectly clean as the alcohol might extract remaining flavour from plastic-lined lids of jars previously used for other foods. Filter through filter paper (paper coffee filter works fine), giving a highly concentrated caraway extract. Dilute with the 450 ml ethanol, rinsing the caraway seeds and filter paper with some of the ethanol in order to recover all the extract. It is perfectly drinkable right away, but will round of well if left to mature, preferably for 3-5 months. Goes well with strong flavoured meats such as mutton or game.

Reference
Øvrum, R.: Akevitt av egen avl. Cappelen Damm 1999.

Leavens in cookies - theory and practice

Recently, I published a popular science article in Norwegian. Title might be translated "Christmas cookie chemistry, ...and some physics" on www.naturfag.no/mat. Focus is testing the effect of using different chemical leavening agents on the same cookies (yeast is hence not the issue here). A summary follows.

All photos (unless otherwise stated): Erlend Krumsvik

Why do some recipes require baking powder, others ask for baking soda, and yet others want hartshorn (baker's ammonia). For some cookies, various recipes for the same cookie even ask for different leavening agents. Puzzling...

(In writing this, I've realised that hartshorn is a rather rare ingredient in English speaking countries(?), even though it's still common in Scandinavia, and possibly also in central Europe. See references in the end for some information)

The chemistry, in short

• Baking soda = sodium bicarbonate = NaHCO3. Requires acidic ingredient in order to produce CO2 (but see below)
• Baking powder = baking soda plus (most commonly) two solid acids, one reacting at room temperature whereas the other doesn't react before heated. Does not require acid but does require water in order for the reagents to react.
  
• Hartshorn = bakers ammonia = ammonium bicarbonate = (NH4)(HCO3). Does neither require acid nor water (but water may be used if required by other reasons). Reacts at higher temperatures only.

The two former produce CO2, whereas the latter produces both CO2 and ammonia (NH3). In all cases, gas production results in bubble expansion, giving porous and levened cookies.

Physics, in short
Either whipping eggs with sugar or creaming butter + sugar generates bubbles. When placed in the oven, the air in the bubbles expand and (more importantly) water evaporates expanding the bubbles.

Discussion
Both baking powder and hartshorn do not require any other ingredient to work properly.

Baking soda, however, needs some acid (i.e. lactic acid from sour cream or buttermilk, syrup etc.). Heating pure baking soda releases some gas, but half of the baking soda remains as sodium carbonate (Na2CO3, soda). This might give a soapy bitter taste. Also, baking soda alone results in a dough in the basic pH range (opposite of acidic). In short, higher pH promotes Maillard reactions, resulting in darker cookies and more pronounced baking/caramel/nutty flavour. Also higher pH retards gluten formation, resulting in shorter texture (or more correctly, low pH promotes gluten formation).

Hartshorn liberates CO2 and ammonia. Ammonia is quite a basic substance, and seems to give rather marked different results compared to the rest (see below). Also, harthorn gives crisp, brittle and porous cookies. I haven't found any sources say exactly why, however (frustrating...). One reason might simply be of physical nature: cookies made with hartshorn are perforated due to bubble formation in a rather dry dough, resulting in cookies with lots of small holes.*

Results
Made "tyske skiver" (shortbread cookies) and "sirupssnipper" (variety of gingerbread cookies).

(Click for table in pdf format or here for table in html format)

Of course, there are lots of variables to take into account in addition to the ingredients; baking temperature, baking time, inhomogenous temperature in the oven, using more than one tray, craftsmanship etc. The experiments above were conducted in identical fashions as far as possible. The various versions were not baked on the same tray, however, which would have given the most comparable results.

Some rules of thumb

• For soft cookies: use baking powder, alternatively baking soda plus and acidic ingredient
• Extra brown/dark cookies: use (more) baking soda. Not recommended if the cookies have a mild flavour, strong flavour might/will mask the taste of sodium carbonate (soda). Hartshorn might work, but has other side effects.
• Brittle/crisp: hartshorn
  
• Short texture: avoid working dough with water. Crumble flour and butter thoroughly. Keep pH above neutral by using (or adding a little) baking soda, or use hartshorn.

Skipping the leavening agent altogether is also an alternative that should be considered.


General quantities and conversions

• 1 ts baking powder = 1/2 ts hartshorn = 1/4 ts baking soda
• amount of acid for 1/2 ts baking soda ↔ ca. 250 ml buttermilk or 1 ts lemon juice/vinegar
• 1 ts baking powder ↔ 250 ml (150 g) flour
  

References
Belitz, Grosch & Schieberle: Food Chemistry (3. ed.). Berlin: Springer 2004.
Gardiner & Wilson: The Inquisitive Cook. New York: Henry Holt & co 1998.
McGee, H.: McGee on Food and Cooking. London: Hodder and Stoughton 2004.
O’Corriher, S.: Cookwise. New York: William Morrow 1997.
Olver, L.: The Food Timeline


* Harold McGee has an interesting entry on hartshorn, however erraneously stating that ammonium bicarbonate does not release water. Indeed, it does as seen from the reaction scheme below. I gues, the main point is that hartshorn does not require water to funtion, allowing for rather dry doughs (flour - sugar - butter).

The food timeline

A visit by The Food Geek made me aware of this treasure of a web site. The food timeline gives a comprehensive overview on the history of various foods and dishes. When teaching food topics, historic facts (or myths) are often excellent starting points. The problem is that such information isn't really very easy to get to. Here, loads of fascinating information is organised in a straightforward and highly effective way.


The site is far more than a timeline with information on foods and dishes, though:

• historic cookbooks
• economics & historic prices
• Christmas food
• meal times
• references to various literature
• free e-mail answer service promising answer withing 24 hours! (I haven't tested it yet, however)
• tips and strategies in searching for historic information on food
  

Finally, citing the pages: "Information is checked against standard reference tools for accuracy". Also their book shelf is quite impressive.

Highly recommended


Late addition: I submitted a question (on hartshorn) and received an answer less than two days later. Not bad at all, taken that the service is free and done by a professional

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.