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.
When many people hear molecular gastronomy, they think of culinary foams, originally introduced by Ferran Adria at El Bulli. In case you’re fed up with the foams, here’s a T-shirt to express your feelings:
Personally, I can’t even say I’ve taste any of these foams yet… Guess I’ll wait a little with the T-shirt then 😉
The kits illustrate the use of various hydrocolloids to produce foams, gels, dispersions, emulsions and pearls. The principle of flavor pairing is illustrated and binary taste interactions are explored. They also include experiments to explore crunchy vs. soft textures. Each kit comes with four different experiments and enough ingredients to make 8 servings. Furthermore they let you serve every experiment at two different tempereatures. This is neat because is allows you to explore the great influence temperature has on texture and aroma. Each kit sells for $125 – expensive yes, but from the presentation it seems like a good bundle.
Science tasting kit no. 1
The following is illustrated in kit no. 1:
Experiment 1: foaming of pectin and gelatin gels, spherification of a fruit juice/chocolate emulsion (there’s no info on this, but I guess the spherification is alginate based)
Experiment 2: explore how temperature influences sweet and bitter tastes, make a chocolate emulsion (with cream, strawberry juice, wine, cocoa butter and oil) and serve it at two different temperatures
Experiment 3: explore the fact that “taste” is 80% smell, illustrate how salt can suppress bitterness, use a special powder made from an aromatic liquid and maltodextrin which is then dried under vacuum with microwaves (sort of like freeze drying, only this uses microwaves in stead)
Experiment 4: Hervé This’ double dispersion chocolate “cake” made with chocolate and egg white foam which is set in a microwave oven (described in his Angewante Chemie article on molecular gastronomy), short lived crunchy texture, flavor pairing is illustrated by combining cumin and coffe with chocolate
Science tasting kit no. 2
Kit no. 2 starts of by exploring culinary “equations” which are remarkably similar to (yet somewhat less comprehensive than) the CDS formalism described by Hervé This elsewhere. The following is illustrated in the second kit:
Experiment no. 1: a “whisky” is constructed from ethanol lignin, aromatic aldehydes, sugars, acetic acid, oak flavor, vanilin, malt etc.
Experiment no. 2: ice cream is made without churning using foamed egg whites to incorporate air (is this what Italians refer to as a frozen parfait?)
Experiment no. 4: meringues floating on a pool of custard sauce drizzled with caramel
If you’d rather reverse engineer the dishes, my list of hydrocolloid suppliers might come handy. The “tasting notes” also gives you some hints if you want to have a go on your own.
An object does not need to be superconducting to levitate. Normal things, even humans, can do it as well, if placed in a strong magnetic field. Although the majority of ordinary materials, such as wood or plastic, seem to be non-magnetic, they, too, expel a very small portion (0.00001) of an applied magnetic field, i.e. exhibit very weak diamagnetism. The molecular magnetism is very weak (millions times weaker than ferromagnetism) and usually remains unnoticed in everyday life, thereby producing the wrong impression that materials around us are mainly nonmagnetic. But they are all magnetic. It is just that magnetic fields required to levitate all these “nonmagnetic” materials have to be approximately 100 times larger than for the case of, say, superconductors. This experiment was conducted at the Nijmegen High Field Magnet Laboratory.
This is slightly off-topic, but take a look at these two videos on mechanical gastronomy. First one is a lego-machine that opens a bottle of beer. The second one is a Rube Goldberg (homepage, Wikipedia) machine that pours a beer (jump to 2:10 if you want to skip the intro and just watch the action). Rube Goldberg described his cartoons as “symbols of man’s capacity for exerting maximum effort to accomplish minimal results”, but has since given name to complicated machines that perform simple tasks!
Have you ever though about how far you can shoot a champagne cork? The swedish physicist Hans-Uno Bengtsson has actually done the necessary calculations in the wonderful Swedish book “Kring flaskor och fysik” (which translates to something like “Among bottles and physics”, it was written together with sommelier Mischa Billing). Assuming a bottle pressure of 6 atmospheres, a cork length of 25 mm (the part in contact with the bottle), a radius of 9 mm and a mass of 7.5 g, this gives an initial cork velocity of approximately 20 meters per second or 70 km/h! This translates into a maximum shot length of around 40 m (if we neglect air resistance). In case you prefer not to shoot the cork, you could of coarse turn to a saber or a heavy kitchen knife instead to open the bottle.
When opening a bottle of champagne, you might have noticed the cloud forming right above the bottle neck (see picture below). This is due to a significant temperature drop, caused by gas expansion when we open the bottle. Assuming an adiabatic expansion (meaning no heat exchange with the surroundings), Hans-Uno Bengtsson has calculated a temperature drop of 112 °C! No wonder the vapor around the bottle neck immediately freezes forming a small cloud.
If this doesn’t satisfy your craving for champagne science, there’s a whole book on the subject: “Uncorked – The Science of Champagne” by Gérard Liger-Belair. He’s an associate professor of physical sciences at the University of Reims Champagne-Ardenne and probably knows more about champagne bubbles than anyone else! In addition to many fascinating pictures of bubbles, the book has many interesting facts. Did you know that:
0.1 liters of champagne (the contets of an average flute) contains approximately 0.7 liters of carbon dioxide which must escape to restore equillibrium – assuming an average bubble size of 500 micrometers in diameter this corresponds to 11 million bubbles!
Contrary to popular belief, nucleation sites for bubbles are not found on scratches or irregularities on the glass itself, but on impurites stuck on the glass wall. These impurities are typically fibres from paper or fabrics.
From the point when a bubble leaves the nucleation site till it reaches the surface, the volume increases by a factor of 1 million. This is due to diffusion of carbon dioxide from the solution and into the bubble.
Surfactant molecules in champagne form a protective shield around the rising bubbles. This stiffens the bubbles and significantly increases the drag on the bubble as it rises (which gives us more time to admire the trail of bubbles!).
The surfactant coating of the bubbles helps keeping them in line as they rise. In pure water, the bubbles would jostle around.
The bursting bubbles play an imporant role in flavor release as they collect and concentrate surface active molecules which are thrown against your nose once the bubble bursts, creating a cloud of droplets.
(these facts should be perfect conversation starters!)
Why does a pot roast brown in a crockpot? It seems to be steaming in the pot, which one would think would create a blanched and pale cut of meat, but it comes out as browned as if we had seared it on the stovetop (not that I’m complaining).
[…]
Now, did I say the Maillard browning reaction involves parts of sugar molecules?
Yes, I did.
Does that mean there are sugars in the meat?
Absolutely not.
Then what the. . . .
Easy, now. Let me explain.
A carbonyl group is indeed a certain grouping of atoms found in sugar molecules. But it also is found in many other kinds of molecules, including the meat’s very own fats and proteins. The Maillard browning process can use the carbonyl groups that are inherent in the meat; it does not require sugars. And that’s fortunate, because there are no sugars in meat, beyond perhaps traces of glycogen, a source of glucose that fades away following the animal’s death.
[…]
Check out the other posts – there’s a lot to pick up for anyone interested in the food and science (especially if you like Wolke’s anti “tech speak” jargon – otherwise I would suggest reading McGee instead)!
Under the heading “The Curious Cook” Harold McGee recently started an occasional column on food and chemistry and everything in between in the New York Times. It’s definitely worth reading as Harold McGee has time and opportunity to really dig into these matters. Also, don’t forget to check out his blog. The latest post on his blog provides more detail on the blue-green colors in garlic and onion, discussed in the NY Times column.
