Friday, February 26, 2010

Chilling your wine with salt

The Kitchn recently had a post about how to chill a warm bottle of wine quickly using salt.

There is an interesting little debate in the comments section about the science behind this phenomenon and the use of an ice/water mixture vs. ice in cooling wine. I'll take the liberty of giving you the DL on what's up.

First off, a ice/water mixture will cool the bottle of wine faster than ice alone. Why? It has to do with energy transfer (thermodynamics to the rescue!). In order to chill the wine, the heat in the bottle of wine needs to be transferred to its surroundings. This will only happen if the surroundings are colder than the bottle (obvi.). Liquids are better at transferring heat energy than gases (like air). If you pack some ice around a wine bottle, there are many pockets of air insulating the bottle from the ice. If you add some water, the liquid flows into these pockets, contacts the wine bottle, and begins to absorb the bottle's heat energy, cooling it.

So why add ice at all? Basically, to cool the water that's cooling the wine bottle. Ice is a crystal of water molecules. Melting of ice requires breaking up the ice crystal, which requires energy. This energy is taken from the surrounding water, dropping the temperature of the water to about the melting point of the ice. Good contact with this cold water will quickly chill the wine bottle.

Where does the salt come in? Well, adding salt to this system lowers the temperature, cooling the bottle faster. This is the same principle at work when you make ice cream in an old-fashioned hand crank machine or when you salt your driveway when it's icy. Adding salt to the water lowers the freezing point of the mixture. Once you add salt, the freezing point is now lower than the temperature of the mixture. More melting than freezing begins to occur, which means that the system is absorbing more energy than it releases, so the mixture cools. That's why ice water with salt is colder than ice water without.

Another note: the water will cool the bottle faster if you re-distribute the warmed water by agitating the bottle a little as it cools. This ensures that the bottle is always in contact with cool water by mixing up the water and ice in the container. It's also why a frozen item will thaw much more quickly in moving cold water than in will hot water, but perhaps that's another post...

Tuesday, February 23, 2010

Ode to a prune

I'll let you all in on a little secret - prunes are awesome, and I love them. I know the have a bad rap - as nature's laxative and food for old people, but they can be spectacular.

I say this especially of Pruneaux D'Agen, which are prunes from the south of France near a town called Agen where they take their name. These babies are large, tender, and delicious - they remind you that they used to be a fruit. I firmly believe that even prune haters should at least give them a shot. Unfortunately, they can cost quite a bit - a brief internet search comes up with prices around $16/lb. (!!). Luckily for New Yorkers, Fairway market sells them in bulk for $6.99/lb. Sweet. Literally. They're worth it, too - one taste of these and you'll never go back to Sunkist.

Pruneaux (that's French for "prunes") D'Agen have Protected Geographical Indication (PGI) from the E.U., meaning that if they are labeled "Pruneaux D'Agen" they are from a specific region in France and are subject to production oversight. They are naturally dried with no added preservatives, so I recommend keeping them in the fridge and warming them up to room temperature before serving, but keeping them at room temperature is okay, too.

Like all prunes, if you eat a bunch of them, they can have a laxative effect. This is because they contain a good bit of dietary fiber (about 6% by weight) like most dried fruit and also contain a naturally occurring laxative called dihydrophenylisatin.

I love to just eat them, but they are also great in recipes. They can be cooked with red wine or liquor and used as a topping for ice cream, a filling for pastry, etc. Maybe my favorite prune recipes is this one for Brandied Prune and Chocolate Chunk Cookies from The Kitchn. It mimicks a candy that I loved as a kid and still adore - chocolate covered prunes. We used to get them from the Polish shop in our neighborhood and called them Sliwka (pronounced schleev-ka) - Polish from plum. These cookies have that great chocolate and prune taste, with just a little added booziness. Yum!

Enjoy your prunes!

Wednesday, February 17, 2010

Science Cookies!

I get so excited when I find people combing my favorite (and only) livelihood (science) with my very favorite hobby (cooking). There is a super crafty and exciting example of these two worlds colliding at Not So Humble Pie, where Ms. Humble, blog proprietor, has amassed an awesome assortment of science themed cookies (from herself and other geeky bakers). Can you recognize the ones above? They're little electrophoresis gels. Squee! Check them all out here.

(via The Kitchn)

Marion Nestle and the Future of Food

The Kitchn has a rundown of a recent talk by Dr. Marion Nestle, Professor of Nutrition, Food Studies, and Public Health at NYU. Apparently, good news - she thinks we (meaning our society) are not all doomed to die of diabetes, as long as we stop eating so much processed corn by-products. Word.

Monday, February 15, 2010

Friday, February 12, 2010

Eating to Starve Cancer

There is an interesting summary of a presentation by Dr. William Li from the TED conference at BoingBoing. His talk discussed foods that prevent angiogenesis and thus prevent cancer from becoming deadly. File under: more good reasons to eat your fruits and veggies.

DIY Chicken Stock

(this is NOT chicken stock)

Once you figure out that making home made chicken stock isn't difficult, you'll look back with shame and sadness at all of the wasted roast chicken carcasses of your pre-enlightenment days.

Home made chicken stock is full of finger-licking goodness due to the presence of gelatin. Gelatin is formed when collagen, a protein found in animal connective tissue, is hydrolyzed (broken down). This process takes some heat and time to occur. That's why bones, tendons, ligaments and cartilage, though not tasty on their own, become tasty through the miracle of a long, slow simmer. It's also this finger-licking-goodness that you miss when you use powdered stock - it generally contains salt and chicken flavor but lacks delicious hydrolyzed proteins. Stock that comes in a can or carton is better, but still can contain some artificial ingredients and is generally inferior to homemade stock.

Lucky for us, homemade stock is easy and cheap to make! The Kitchn has a great DIY guide to making home made chicken stock, but here is my take (somewhat similar, with some hacks to make it easier and a little cheaper).

Chicken Stock Protocol

Materials: roast chicken carcass, vegetable scraps, garlic (optional), whole black peppercorns (optional), 2 pots large enough to hold everything, strainer, cheesecloth, several containers to hold finished stock ( about 1-2 quarts per chicken)

1) Take the remains of one or more roast chickens (bones, cartilage, and bits of meat, avoid the skin) and put it into a pot that fits snugly.
2) Add in several handfuls of vegetable detritus. I use celery ends, carrot ends and peels, onion ends and skins, herb stems, etc., but use whatever you have got on hand. This makes great use of what is otherwise garbage and saves more useful veggies for another meal. Add in a couple crushed cloves of garlic and some whole peppercorns if you have them.
3) Cover the solids in the pot with about an inch of water. Bring to a low simmer for 3-4 hours - you will see some bubbles, but try to avoid a real boil.
4) Line a strainer with cheese cloth and place that inside another pot to catch the finished stock. Pour the chicken stock and solids through the strainer.
5) Aliquot stock into containers to be refrigerated (about a week) or frozen (indefinitely). For this purpose I like the re-usable twist-top storage containers or re-used takeout soup containers.

- If you notice that there is a lot of fat floating on top of the stock, refrigerate overnight then remove the solidified fat with a spoon and then freeze or use the stock.
- If you don't have enough time or materials to make stock after roasting a chicken, put the parts in a bag or plastic container in the freezer until you do have time. In the mean time, toss any veggie scraps that you generate into the container for making stock.
- This method can be used for any amount of chicken leftovers - just scale up.
- You can also make other kinds of stock this way - try turkey stock after Thanksgiving, or buy a bunch of soup bones and make beef stock.

Friday, February 5, 2010


Topless Robot presents a list of essential cookbooks for the nerd kitchen. I want all of them. Especially number two. I can hear someone, somewhere, yelling, "NERD!"

Thursday, February 4, 2010

Food Fab

That's fab as in fabrication, not fab as in AB-solutely FAB. Or maybe it's both?

Salon has an interesting piece up about a concept food fabrication machine called the Cornucopia that is the idea of two MIT grad students. Basically, it uses tubes of ingredients that it can heat, cool, and otherwise manipulate into meals using a program.

It all seems very interesting, but I think in reality the best that this technology will achieve is being the centerpiece of a gimmick restaurant. Maybe I'm biased as a cook, but I think a machine will never replicate the experience of a meal well-cooked by a caring human. It still has to be programmed by a person and it seems cost-prohibitive into the foreseeable future. Plus it doesn't exist yet except in the minds of its creators. But maybe there's a place for this in a space station somewhere where some government or another can foot the bill?

For the mean time, you can build this DIY open-source CandyFab from Evil Mad Scientist and print yourself out some cool 3D sugar sculptures for just $500 and some precious spare time.

Tuesday, February 2, 2010

Is your bread the same species as you pasta?

(image via wikimedia commons)

Have you ever wondered about the genetics of dinner at an Italian restaurant? Probably not. Chances are, though, that the species of wheat in your garlic bread was different than the one used to make your spaghetti.

Humans have a complicated relationship with wheat. We've been cultivating many species for thousands of years and have molded these species' characteristics using selective breeding. Many wheat species are polyploid, meaning that they have more than two sets of chromosomes (that's how many humans and most animals have), which generally makes genetic manipulation difficult. However, Monstanto, the largest producer of genetically modified crops, is developing genetically modified wheat, although it won't be on the market for several years.

Some people have a severe intolerance to wheat gluten, a protein found in wheat, called Celiac disease. People with this disease have a severe immune reaction to wheat gluten that damages the intestinal lining, causing a host of symptoms. Related proteins found in rye and barley will likely also cause these symptoms. Since all species of wheat are related and produce similar proteins, Celiac sufferers must avoid all species of wheat in their diets. Currently, there is no cure for Celiac disease, although it can be managed with diet. The exact mechanism is still under investigation.

In case you've ever wondered, here is the 411 on some common species of wheat that you will encounter at your grocery store or neighborhood restaurant:

1) Common wheat or Bread wheat (T. aestivum) is a hexaploid species that is the most commonly cultivated in the world.
2) Durum wheat (T. durum) is a hard wheat used to make semolina flour for pasta.
3) Spelt (T. spelta) is a wheat species that is recently gaining in popularity but still less prevalent than other types.
4) Emmer wheat (T. dicoccum), also known as Farro, was widely cultivated in ancient times but is less prevalent now. It was specifically referred to in several ancient texts.
5) Einkorn wheat (T. monococcum) is a rarer type of wheat that may be less toxic to Celiac sufferers1

Additionally, there are many, many other species of wheat that I don't have the space (or frankly the willpower) to go into here. Interested parties are referred to this excellent Wikipedia article.

Wheat is usually ground into flour, using all (in the case of whole wheat) or part (in the case of white) of the wheat kernel. In general, "hard" wheats contain more protein, which makes dough made from their flour more chewy and elastic. They are best for bread and pasta, whereas "soft" wheats contain less protein and are best for cakes, biscuits, etc. "All-Purpose" flour is usually a mix of these two types and can be used for a wide variety of purposes, hence the name.

1Pizzuti D, Buda A, D'Odorico A, D'IncĂ  R, Chiarelli S, Curioni A, Martines D (November 2006). "Lack of intestinal mucosal toxicity of Triticum monococcum in celiac disease patients". Scand. J. Gastroenterol. 41 (11): 1305–11.