The Scientist in an interview with Hervé This reports that:

Recently, New York University Assistant Professor of Chemistry Kent Kirshenbaum teamed up with chef Will Goldfarb to bring experts together to discuss the intersection of science, cooking and eating. Often they are talking about the same thing, but with different vocabulary, says Kirshenbaum, who specializes in the architecture of polymer chains. “I think of these as reagents. He thinks of them as ingredients.”

The initiative of Kent Kirshenbaum and Will Goldfarb resulted in The Experimental Cuisine Collective which was officially launched on April 11th with a workshop entitled “Experimental Cuisine: Science, Society, and Food”.

Their mission statement is an elaboration and expansion of Hervé This’ original and revised definitions of molecular gastronomy (ie. not excluding the technological and political aspects of molecular gastronomy, and including the social context):

Provide a venue for scientists, food academics, culinary and pastry professionals, journalists, and the dining public to gather and exchange knowledge.

Contribute to a rigorous scientific understanding of the physical basis for cooking processes.

Enhance understanding of the social contexts for cooking and the societal ramifications of new food technologies.

Accelerate the discovery of scientific and experiment-based approaches to innovative culinary practices, unorthodox flavors, and new dining traditions.

Provide technical expertise for chefs.

Advocate for a balance between modern cuisine while maintaining a healthful and sustainable approach to food preparation.

Disseminate knowledge about human diet and health; inform the public regarding the molecular basis of nutrition and the chemical constituents of food; and foster research that will improve people’s ability to obtain and choose healthful foods on a local and global level.

Introduce curricula on food and cooking as an approach for generating enthusiasm among school children for studying the physical sciences.

Celebrate taste.

Their mission statement sums up many of my interests related to molecular gastronomy and popular food science and I look forward to their contributions! And I really hope they will publish their results and findings on the web.

The New York Academy of Sciences has an interesting series on the Science of Food. On April 10th Hervé This, a pioneer of molecular gastronomy, talked about “Dinner: The Final Frontier”. An interview with This and the other speakers is now available for free download:

For the food blogging event They Go Really Well Together (TGRWT #1) I decided to used baked garlic. Baking gives garlic a slightly sweet, mellow taste and I figured this might work well with the soft texture of an espuma. Just make sure you get fresh garlic without green sprouts - they will give a bitter taste.

4 cloves of baked garlic (baked whole, 30 min @ 150 °C)
3.5 dL strong coffee
30 g sugar
40 g chocolate (70% cocoa)
ground cardamom
3.4 g gelatin (= 2 sheets)
1.5 dL heavy cream (38% fat)
1 iSi cream charger

Mix garlic cloves and coffee with blender or hand-held mixer. Add chocolate, a pinch of cardamom and heat while dissolving sugar. Stir in pre-soaked gelatin. Cool, add heavy cream, sift through fine mesh to remove remaining pieces of garlic and fill 0.5 L iSi gourmet whipper. Charge with 1 cream charger and leave in fridge over night. Serve with a drizzle of instant coffee.

How it tastes? In the finished espuma served cold, the first aroma noticed is coffee accompanied by a sweet taste on the tongue. This is followed by a faint chocolate aroma which then gives way for an aftertaste dominated by garlic. It’s quite surprising and the aromas blend well together. I used 30 g of chocolate, but I’ve increased it to 40 g in the recipe since the cocolate aroma was a little weak. As for uses, I think it would go well with a steak for instance. If used as a dessert I would perhaps reduce the amount of garlic to 2 or 3 cloves so as not to overwhelm the guests (unless they frequent the restaurant Garlic & shots in Soho, London where even the beer is served with garlic!).

Reading the comments on how to prepare a dish using garlic, coffee and chocolate, I figured it could actually be a good idea to make this into a food blogging event. Inspired by Is My Blog Burning (IMBB), Sugar High Friday (SHF) and the like, I hereby launch a new food blogging event called They Go Really Well Together (TGRWT).

The name refers to flavour pairing of ingredients based on their content of volatile aroma compounds. The idea behind flavour pairing is that if two (or more) foods have one or more volatile compounds in common, chances are good that they might taste well together. Click for a list of other flavour pairings and to read previous blog posts on the topic. The molecule shown in the logo is of 2-methylfuran-3-thiol, a very potent aroma chemical found in coffee, chicken, meat, fish and popcorn - to mention a few.

Many flavour pairings seem strange at first, especially when the combination is not found in any recipes. To illustrate the flavour pairing one can always just eat the two ingredients together. But it would be so much nicer to actually make a proper dish out of it. Therefore I’m quite excited to see what the creative minds of all the food loving bloggers can come up with!

This is how the first round of the blogging event works (hereafter referred to as TGRWT #1):

1. Prepare a dish that combines garlic, coffee and chocolate. You can either use an existing recipe (if there is any) or come up with your own.
2. Write a entry in your blog by May 1st with TGRWT #1 in the subject and make sure to include a link to the header of this post for trackback links. Readers will probably be particularily interested in how the flavour pairing worked out, so make an attempt at describing it.
3. Deadline for submissions is May 1st. A round-up will be posted by me here some days later with pictures.
4. Please send me an email at webmaster (at) khymos (dot) org with the following details: Your name, URL of blog and URL of the TGRWT #1 post and a picture for your entry in the round-up.
5. If you don’t have a blog, email me your recipe, name and location and I’ll be glad to include it in the final round-up.
6. In due time I will ask one of the participants to host the next round on their blog (and provide an updated logo).

Google can be of great help when exploring flavour pairings, especially for those of us who don’t have access to the commercial database VCF. The following tip has been mentioned in a comment to a previous blog post, but I thought it could be a good idea to bring it to everyones attention:

The Good Scents company has en extensive range of aroma components, and the nice thing is that they list natural occurences and uses. The latter I guess, is based on the organoleptic properties of the aroma compounds. Using google, it’s possible to check if two or more foods have anything in common. Just type in the foods of interest and add site:http://www.thegoodscentscompany.com at the end. The triple combination in my last post for instance gives the following search string (click to perform the google search) and the top 5 hits are:

furfuryl mercaptan * 98-02-2
benzothiazole * 95-16-9
isovaleraldehyde * 590-86-3
bis(2-methyl-3-furyl) disulfide * 28588-75-2
5-methyl furfural * 620-02-0

The numbers following the name of the aroma compound are CAS registry numbers and indentify each compound uniquely. They are often more useful than the chemical name when searching the internet and databases.

Unfortunately there is no way to distinguish whether the foods listed for each aroma compound occur under the “Natural occurences” or “Used in” labels.

Preparing for a presentation on flavour pairing, Bernard Lahousse at Food for design visited François Benzi at Firmenich, a large supplier of aroma chemicals and perfume ingredients. Bernard plans to launch a website dedicated to flavour pairing soon, and in the mean time he posts about it on his blog, including this interesting expansion of the flavour pairing concept:

…you can also use foodpairing to pair food that doesn’t match. Like chocolate and garlic. The trick then is to search for a third food product that has something in common with chocolate and with garlic. An example is coffee. Coffee has flavour components in common with garlic: Dimethyl disulfide and with chocolate: Methyl pyrazine.

My challenge to you all is to come up with recipes that include garlic, chocolate and coffee. Any suggestions?

Were you told by your mom to chew each mouthful 20 or 32 times before swallowing? Her rationale was perhaps to prevent you from choking. But it turns out there is a link between chewing (or mastication) and release of aroma molecules. A group of French researchers have studied model cheese systems with varying hardness (J. Agric. Food Chem., 2007, 3066, 10.1021/jf0633793). Their key finding was that in hard cheese, more aroma is released, and it happens at a faster rate than in softer cheeses. It is slightly counter intuitive, because one would expect that volatile aroma molecules would have a harder time escaping from a hard surface than from a soft surface. The reason however is that when chewing a hard cheese our chewing pattern automatically adopts and we chew more intensely. Furthermore a hard cheese will break down into several pieces when chewed, resulting in a greater surface area from which the aroma components can escape into the air.

(Photo by kurafire at flickr.com)

Heston Blumenthal has investigated how sound affects chewing, but I didn’t know that sound was so important for how we perceive the taste of apples. Studying particularily crisp apples, named Jazz apples, researchers found the following:

Professor Povey said, “When you munch a Jazz apple you create pulses of sound containing large amounts of ultrasound which our brains interpret differently from ordinary sounds such as speech. The pulses are so intense that if they were sustained as a tone, they would destroy our hearing.”

“It appears that ordinary hearing is short-circuited somehow and the greater the number of pulses of sound, the crisper we think the food is. Ultrasound is sound that is beyond the range of normal human hearing but it helps shape the noise into pulses that sound quite different.

“Our group of subjects were culturally diverse but all were able to identify crispness similarly. So perhaps there is a genetic disposition to the appreciation of crispness which has evolved as a sign of freshness in food.”

In a comment to my post on making carbonated fruit the iSi way, JoJo at eat2love made me aware of a company, FizzyFruit, that actually sells carbonated fruit in pressurized containers. The fruits currently available are grapes, honeydew and cantaloupe. Turns out that their homepage features some recipes by - surprise, surprise - Homaru Cantu! Here are some of the recipes:

Proscuitto and melon
150 g carbonated melon
12 slices proscuitto ham
1 dL balsamic vinegar, frozen, shaved to snow
salt
olive oil

Wrap melon pieces with proscuitto, season with salt and drizzle with olive oil. Scatter balsamic “snow” over the top just before serving.

Champagne and Crab
150 g carbonated grapes
350 g picked crabmeat
1/4 bunch of chives, chopped
1 diced shallot
1 orange, juiced and zested
1/2 dL mayonnaise
1/2 dL fennel, shaved thinly
salt

Toss crab with shallot, fennel, mayonnaise and orange juice/zest. Season with salt and leave in refridgerator for 1 hour. Add carbonated grapes, toss with crab mixture and chives. Serve immediately.

Orange Sangria
2 L fresh squeezed orange juice
150 g carbonated fruit (grapes, melon)
8 sprigs of crushed mint
5 dL of crushed ice

Combine ice, orange juice and mint. Add carbonated fruit and serve immediately.

Fresh Fruit Trifle
150 g carbonated fruit (grapes, melon)
2.5 dL fresh whipped cream
1/2 vanilla bean scraped

Add vanilla bean scrapings to cream and whip until stiff peaks are formed. Layer carbonated fruit with whipped cream and serve immediately.

Ants on a Log
150 g carbonated grapes
2.5 dL of chunky peanut butter
4 long ribs of celery

Rinse and dry celery. Fill celery with peanut butter. Stud the celery with the carbonated grapes. Serve immediately.

(The recipes were made generic and converted to metric units)

Based on some googling of espuma and foam recipes (including Ferran Adria’s coffee espuma), I figured that the following should work:

2 dL coffee
2 sheets of gelatine
3 dL heavy cream
sugar/vanilla sugar

Soak gelatine in cold water. Strain. Dissolve gelatin sheets in the hot coffee and stir in sugar while heating. Cool. Add heavy cream. Filter through a fine meshed sift (just in case there should be any undissolved sugar, gelatin or particles) into a 0.5 L iSi gourmet whipper. Screw on top and charge with a cream charger. Shake 2-3 times and leave in fridge for a couple of hours. Hold whipper upside down, shake once to displace mixture towards the nozzle in case it is stuck and dispense. Texture is soft and silky. Tastes delicious!

Some more chemistry: The cream chargers contain dinitrogen oxide (N₂O) which is less polar than carbon dioxide (CO₂), and hence more soluble in fat (such as heavy cream for instance). Another reason why carbon dioxide is not used in this recipe is probably that when it dissolves, some carbonic acid is formed which could curdle milk based products if pH drops to much and also influence taste (but carbonated milk has actually been marketed!). The idea of using dinitrogen oxide for soda/beer has also been explored.

I blogged about carbonated strawberries some while ago. Those were made using dry ice which unfortunately is not always easy to get hold of. Last week however I bought a iSi Gourmet Whipper - one of those Ferran Adria uses to make foams/espumas. I plan to experiment with that as well, but the first thing I decided to prepare was carbonated fruit. In fact this is a safe way (the only?) to make carbonated fruit at home using a pressurized container.

The instruction booklet which comes with the iSi Gourmet Whipper only mentions cream chargers (filled with N₂O, dinitrogen oxide), whereas soda chargers (filled with CO₂, carbon dioxide) are not mentioned (I guess the opposite is true for the iSi Siphons?). This is quite amazing actually! Luckily however the cream and soda chargers are exactly the same size and both hold 8 g of gas. So it should be possible to make carbonated fruit with any of the iSi whippers (cream, easy, gourmet, dessert, thermo) or siphons available.

Here’s how you proceed:

1. Fill you iSi whipper (or siphon) with fruit, preferably fruit which has a cut, wet surface to allow the carbon dioxide to dissolve in the water/juice.
2. Screw on top securly
3. Charge with one soda charger (two if you have the 1 L whipper)
4. Leave in fridge over night
5. Release pressure with valve (Important!)
6. Unscrew top and serve immediately!
7. Enjoy!

This is what carbonated grapes look like. As you see, I decided to cut the grapes in to halves.


Notice how they sizzle!

A quick recap of the chemistry: cold water dissolves more CO₂ than tempered water, that’s why we leave it in the fridge. Also, remember that it takes some time for the carbon dioxide to dissolve in water, therefore it’s better not to be in a hurry. A quick calculation of the pressures gives the following: Both gases have molecular weights of 44 g/mol, so 8 g of gas corresponds to 0.1818 moles or 4.1 L at 25 °C and 1 atm pressure. The volume of the chargers is 0.01 L which gives an initial pressure in the chargers of impressive 445 atm! With an approximate volume of 0.7 L this gives a pressure (in an empty whipper) of nearly 6 atm - the same as in a bottle of champagne. However once you add water, the equilibriums will change and the pressure in the head space will drop. Anyone who remembers how to calculate the head space pressure at equilibrium if the container is filled with 0.5 L of water and cooled to 4 °C?

I’ve done some googling and there is also some mention of making carbonated fruit with an iSi whipper over at Ideas in food.

(The word play in the title works better for those with a mother tongue where iSi would be pronounced just like “easy”!)

About.com has a nice guide on how to color eggs, and the list of colors is quite impressive (click for instructions):

Lavender
Small Quantity of Purple Grape Juice
Violet Blossoms plus 2 tsp Lemon Juice

Violet Blue
Violet Blossoms
Small Quantity of Red Onions Skins (boiled)

Blue
Canned Blueberries
Red Cabbage Leaves (boiled)
Purple Grape Juice

Green
Spinach Leaves (boiled)
Liquid Chlorophyll

Greenish Yellow
Yellow Delicious Apple Peels (boiled)

Yellow
Orange or Lemon Peels (boiled)
Carrot Tops (boiled)
Celery Seed (boiled)
Ground Cumin (boiled)
Ground Turmeric (boiled)

Brown
Strong Coffee
Instant Coffee
Black Walnut Shells (boiled)

Orange
Yellow Onion Skins (boiled)

Pink
Beets
Cranberries or Juice
Raspberries
Red Grape Juice
Juice from Pickled Beets

Red
Lots of Red Onions Skins (boiled)

More information about the chemistry behind can be found in the article “Chemistry in the dyeing of eggs” (Journal of Chemical Education, 1987, 291). The article discusses anionic dyes with sulfonate groups. These bond to the cuticle (protein) covering the egg shell forming salt linkages as shown (illustrated using FD&C yellow no. 6):

By lowering the pH (for example by adding vinegar), more amino groups in the proteins covering the egg shell are protonated and thus available for formation of the salt linkages with the anionic dyes.