In a recent survey 72% of chefs say they may want to experiment with molecular gastronomy in 2007. That’s an impressive number and considering the attention molecular gastronomy gets in media I bet many home cooks would want to experiment in the kitchen as well. Here’s a list of things to consider if you want to make a scientific approach towards cooking:

1. Use good and fresh raw materials of the best quality available.

2. Know what temperature you’re cooking at. A dip probe thermometer with a digital read out is a cheap way to bring science into your kitchen.

3. Get a basic understanding of heat transfer, heat capacity and heat conductance. “Heat” in this context des not imply high temperature since it also applies to the understanding of freezing/thawing.

4. Learn how to control the texture of food. Some key points: temperature induced changes (freezing, heating), emulsifiers, thickeners, gelling agents, moisture content, pressure/vacuum, osmosis.

5. Learn how to control taste and flavor. Some key points: flavor pairings, spice synergies/antagonies, influence of temperature (Maillard reaction, caramelization, temperature stability, volatility), taste enhancers, taste suppresants, solubility of flavour compounds in fat/water, extraction.

6. Remember that prolonged exposure to a flavor causes desenzitation, meaning that your brain thinks the food smells less even though it’s still present in the same amount. Therefore, let different flavours enhance each other. Similarly, variation in taste, texture, temperature and color can open up new dimensions in a dish. This is referred to as “increased sensing by contrast amplification”.

7. Be critial to recipes and question authority – they do not necessarily represent “the truth”. Nevertheless, you can certainly learn a lot from the experts.

8. Dare to experiment and try new ingredients and procedures. Do control experiments so you can compare results. When evaluating the outcome, be aware that your own opinions will be biased. Have a friend help you perform a blind test, or even better a triangle test to evaluate the outcome of your experiments.

9. Keep a written record of what you do! It would be a pity if you couldn’t recreate that perfect concoction you made last week, simply because you forgot how you did it.

10. Have fun!

Heat causes many changes in food, but few appreciate how important it is to know at what temperature they are cooking and at what temperature the desired change occurs.

These tips for molecular gastronomy relate to the technical and scientific aspects of food preparation and eating, and I plan to elaborate on each of the points in separate blog posts. However, according to Hervé This’ definition of molecular gastronomy, one should also investigate the social and artistic components of cooking. A good example of this is the “Five Aspects Meal Model” developed at Grythyttan in Sweden (Gustafsson, I.B. et al. Journal of Food Service, 2006, 84.). Although intended for a restaurant setting, the general idea can also be applied for home cooking.

The meal takes place in a room (room), where the consumer meets waiters and other consumers (meeting), and where dishes and drinks (products) are served. Backstage there are several rules, laws and economic and management resources (management control system) that are needed to make the meal possible and make the experience an entirety as a meal (entirety – expressing an atmosphere).

Or to put it differently: average food eaten together with good friends while you’re sitting on a terrace with the sun setting in the ocean will taste superior to excellent food served on plastic plates and eaten alone in a room with mess all over the place.

One last thing: once you’re finished in the kitchen with your culinary alchemy, your gastro physics, your cutting edge science cuisine, your molecular cooking, your hypermodern emotional cooking, your science food or whatever fancy name you attach to it – remember the social and artistic components when you serve the food. Just so people won’t refer to you as a techno chef, a mad scientist or a modern day Willy Wonka. After all, molecular gastronomy is about the science of deliciousness, not technical wizardry.

Questions and topics for future blog posts are welcome at webmaster [a] khymos.org (substitute @ for [a]) or as a comment below.

Click to see the complete comic.

As a followup to the previous posts on chocolate pairings (chocolate sauerkraut cake and chocolate + caraway and other pairings), here’s a picture of an exotic chocolate I got for Christmas. It’s from Schloss Bückeburg in Germany, but a label on the back says it’s made in Austria (possibly by Johannes Bachhalm, one of Austria’s most famous chocolatiers).

Sprinkled on top the chocolate you see green and pink peppercorns! Furthermore it’s flavoured with vanilla, rosemary, juniper and cured red deer meat. What it tastes like? The pepper certainly goes well with the chocolate. Rosemary and juniper add some freshness. The taste of cured meat was more difficult to identify, but I guess it did add som saltiness. All in all very tasty!

Here’s some of the upcoming molecular gastronomy events. The field is really exploding and this list is far from complete. Feel free to add other events in the comments section.

One important aspect of molecular gastronomy is the application of scientific principles to food preparation in a normal kitchen. This can very well be illustrated by discussing the preparation of a steak. The surface of the meat needs to be heated to > 120 °C (250 F) for the Maillard reaction to take place at a reasonable rate. This gives meat much of it’s characteristic aroma. The interior of the meat however should not be heated to more than 50-65 °C (120-150 F) for a rare or a medium rare appearance. If the heat is provided by a frying pan with a temperature typically in the range 120-160 °C (250-320 F), the different temperature required for the interior and the surface of the meat can actually be quite difficult to achieve. Bringing the meat to room temperature before cooking by taking it out of the fridge 1-2 hours in advance helps. Also, half way through the cooking it’s advisable to let the meat rest on a plate to allow the heat to diffuse into the interior and to let the surface cool down a little.

There is however an easier way to make a perfect steak! In restaurants the method has been around since the 70′s and is known under the name sous vide (fr. under vacuum, more info on history of sous vide in this NY Times article). The meat is packed in plastic bags, vacuumed and put into thermostated water baths. This equipment is not (yet?) found in the average kitchen. So here is a simple DIY procedure. You just use a normal plastic bag, leave the meat in the water bath for 30 min (or longer) and then quickly fry both sides to generate the products of the Maillard reaction. You do need a thermometer though to control the temperature of the water bath, preferably one with a dip in probe.

1. Put the meat (I used a rib eye steak for this experiment) in a thick plastic bag. Only put one or two pieces of meat in each plastic bag – this ensures a greater contact surface with the water.

2. Add any spices you like (salt and pepper always works well – for the experiment shown I used curry paste, soy sauce and chili sauce in stead), press (or suck) out the air and close the plastic bag tightly by tying a knot (or use a zip-lock bag). You don’t want any water to enter the bag!

3. Heat a pot of water to the desired temperature (or use hot tap water) and place the plastic bag with meat in the water. Cover with a lid (not shown in the picture) to reduce heat loss. If you use a large pot of water it’s easier to keep the temperature constant. Also, it’s easier to control the temperature with an induction or gas stove top than with an electric plate since there is no additional heating once you turn them off. Regarding the temperature, start with 60 °C (140 F) and experiment from there (or check this table at Wikipedia for doneness temperatures of meat). You should leave the meat in the water for at least 30 minutes – more for a thicker cut. But the good thing is you can leave it for much longer (several hours) provided the temperature does not come above 60 °C (or whatever temperature you decided on). A convenient way to keep the temperature constant for a long time is to put the pan with water into the oven and use the thermostat of the oven.

4. Heat a frying pan, add a fat of you choice, remove meat from plastic bag and brown both sides of the meat. Since you take the meat directly from the water bath it’s already at about 60 °C. Therefore the browning is very fast.

5. A temperature of 60 °C (140 F) gives the meat a pink interior. It’s succulent and juicy. The short frying gives it a nice browned crust and the chewing resistance is perfect. All in all a wonderful combination of taste, aroma, texture and mouth feel!

Note added January 2009:
Since I published this procedure the first time I’ve learnt a lot more about sous vide. The procedure above is a rather crude procedure, but it works. If the meat turns out grey you’ll need to turn the temperature somewhat down. If you’re interested in reading more about sous vide, the best discussion I know of which also includes important safety aspects is Douglas Baldwin’s “A Practical Guide to Sous Vide Cooking”.

Related posts:
A mathematician cooks sous vide
Sous vide cooking joy
Santa came early this year
Upcoming books on sous vide

I have been pondering on the chocolate sauerkraut cake I wrote about, and considering the fact that caraway is a spice used in sauerkraut I did some googling… And voilá – I found a page on different chocolate and cognac pairings! In October 2006 a tasting sessions was held for sommeliers – it was hosted by John Campbell (author of “Formulas for flavour”) and sponsored by Hennesy. Here are the chocolate and cognac pairings that were offered:

“Another interesting flavour to arise was the peanut and Merlot vinegar chocolates. Whilst trialing the combination of a merlot vinegar flavoured chocolate and the Hennessy Paradis Extra Cognac we noticed an unexpected third flavour element, present only when the two were combined: peanut. We underscored this unusual taste discovery by adding salted and roasted peanuts. The result is amazing”

“The long tradition of savouring cognac together with a suitably matched, high-quality cigar led us to the logical conclusion that both of these products must contain taste elements that matched or complemented each other. Once we blended various tobaccos and oak it resulted in a smooth underscore of the tobacco taste that is present when smoking a fine cigar. This coupled with Richard Hennessey makes the experience unique. On further experimentation the Ganache itself delivers the aromas slowly, you therefore savour the chocolate as you would a fine cigar.”

Any cooks out there who can come up with recipe suggestions for the different chocolate dishes? I have added theses pairings to the list of other known pairings.

Caraway seeds (photo by Joyous! at flickr)

After giving a presentation about molecular gastronomy I was asked if I had ever heard about a chocolate cake baked with sauerkraut. I admitted that this was new for me, but that I would be very interested in the recipe. Could it be that this is a new flavor/flavour pairing? Remember, the hypothesis is: if the major volatile molecules of two foods are the same, they might taste (and smell) nice when eaten together. Perhaps there’s some one out there with access to a headspace gas chromatographer that could check this out? Or perhaps someone who has access to the Volatile Compounds in Foods database could do a quick search? If you’re unfamilier with such flavor pairings, another nice pairing with chocolate is the one with caramelized cauliflower and chocolate jelly.

I did get the recipe and it turned out that it was from a cookbook called “Food that really schmecks” by Edna Staebler. The book is a collection of recipes from the Mennonite community in Ontario. Many Mennonites came from Germany, hence the word “schmecks” in the title which is German (zu schmecken = to taste). According to the cookbook, leftover sauerkraut makes the cake moist and delicious – which I can certainly confirm! And the strange things is you can’t really taste the sauerkraut. Here is the recipe (the way I made it):

Sauerkraut chocolate cake
170 g butter (ca. 3/4 cup)
300 g white sugar – less than the 1 1/2 cups in the original recipe
3 large eggs
1 teaspoon vanilla (either essence or vanilla flavored sugar)
2.5 dL water (= 1 cup)
6 dL flour (= 2 1/2 cup)
1.3 dL unsweetened cocoa (= 1/2 cup)
1 teaspoon baking powder
1 teaspoon soda (sauerkraut is sour, therefore the recipe calls for soda!)
1/2 teaspoon salt
330 g drained  sauerkraut (1 1/2 cup) – more than in the original recipe

Mix butter and sugar. Add eggs, water and dry ingredients. Stir in the sauerkraut and pour batter into greased pan. Bake at 350 F/180 C for 30-50 minutes.

The cake was a little too moist in the center when I made it and could have needed a couple more minutes in the oven. Make sure you check if it’s all set by inserting a wooden match or a knitting pin in the center of the cake!

Interestingly, the cookbook “Food that really schmecks” was recently presented in the blog Cream Puffs in Venice, with the following statement attached: “There is no haute cuisine or molecular gastronomy to be found here”. But chocolate and sauerkraut might turn out to be another flavor pairing based on sound chemical reasoning.

Update: Read the followup on this post with more about chocolate and caraway (the main spice in sauerkraut)

Since The fat duck and El Bulli were announced “Best restaurant” in 2005 and 2006 respectively by Restaurant Magazine, molecular gastronomy has received increased attention. This has also resulted in a greater demand for the ingredients used, especially various thickeners, stabilizers and emulsifiers. In Europe, these have been given E-numbers ranging from E400-E499. The other ranges include colours (E100-199), preservatives (E200-E299), acidity regulators, anti-oxidants and anti cacking agents (E300-E399, E500-E599) and flavour enhancers (E600-E699). The European numbering is a sub-set of an international list of food additives, the Codex Alimentarius.

The Alchemist’s pantry – an early predecessor to that of the modern cook! (picture source)

Some of the most used ingredients in restaurant kitchens are listed below:

E322 Lecithin
E327 Calcium lactate
E331 Sodium citrates
E400 Alginic acid
E401 Sodium alginate
E402 Potassium alginate
E403 Ammonium alginate
E404 Calcium alginate
E406 Agar
E407 Carrageenan
E407a Processed eucheuma seaweed
E410 Locust bean gum (Carob gum)
E412 Guar gum
E413 Tragacanth
E414 Acacia gum
E415 Xanthan gum
E416 Karaya gum
E417 Tara gum
E418 Gellan gum
E422 Glycerol
E425 Konjac
E440 Pectins
E441 Gelatine
E461 Methyl cellulose
E463 Hydroxypropyl cellulose
E464 Hydroxy propyl methyl cellulose
E466 Carboxymethyl cellulose
E473 Sucrose esters of fatty acids
E474 Sucroglycerides
E621 Monosodium glutamate
E631 Disodium inosinate
E636 Maltol
E953 Isomalt
E1103 Invertase
E1400 Dextrin
Transglutaminase (no E-number as far as I know)

(click here for the full list)

Unfortunately these ingredients are not available in normal stores (with one exception: gelatine). Of course they are readily available in large quantities to the food industry, but lately suppliers of sub-kilogram amounts have appeared. I have collected a list of these suppliers – if you’re not on the list, drop me a note at webmaster((a))khymos((dot))org). Recent additions to the list include Kalys, texturePro and DCDuby.

One challenge with the different shops is that some products come with little or no technical specification. For cellulose ethers for instance, Dow provides an extensive range to industrial customers (more on this in a previous blog post on cellulose ethers), just to give you an idea of the product range available.

I should also add a closing remark om tools: some companies sell syringes, measuring spoons etc in “nice boxes”. However, these tools can most often be obtained for a fraction of the price at any drug store, pharmacy or kitchen hardware store.

Once you have stocked up with your cooking chemicals, the next question is – how do you use them? I would recommend the information provided by INICON on molecular gastronomy and textures (MANY pdf’s to download). Also, many of the suppliers have recipes on their homepages.

Videos from the MG seminar in Belgium held on November 20th last year have generously been made available for free on the net. There are four videos to watch: presentations by Prof. Peter Barham (‘Molecular Gastronomy? The science of taste and flavour’) and Prof. Jorge Ruiz (‘Methods in the kitchen: the science behind’) plus demonstrations by Kobe Desramault and Sang Hoon Degeimbre.

Also, Bernard Lahousse (who is in charge of food for design and a co-organizer of the MG smeinar) has let me know that the next seminar will be held on March 16th with the title “A world of Pinot noir” – focus is on wine, but with live MG demos. Stay tuned!

Experimental and clinical studies indicate that tea exerts protection against cardiovascular diseases. However, a group of German researchers (abstract, European Heart Journal 2007, ASAP contents) have found that the beneficial effects of drinking tea may be reduced if milk is added to the tea.

(Picture by IreneM entiteld “coffee with a “drop” of milk” from DPchallenge – OK, it’s not tea, but I just love this picture!)

By measuring the blood vessel’s ability to expand (and thereby reduce the blood pressure) the researchers found that this ability was improved by tea, but the effect was completely blunted if milk was added to the tea. It was found that the caseins were responsible for the observed inhibition, probably by formation of complexes with catechins. It is believed that catechins (polyphenolic compounds, belong to the group of flavonoids, structure of epicatechin shown below) trigger the release of other active substances that are responsible for the expansion of blood vessels (also known as vasodilation).

The results of this study are not limited to tea, because catechins are found in many other foods, including citrus fruits, wine and chocolate.