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Monday, November 23, 2009

Science to cooking Thanksgiving

Follow me on this meandering train of thought about festive molecular gastronomy on the cheap.

Perhaps one of the newest techniques to emerge in the field of cooking is sous vide, and it's taking  much of the new chefs by storm. In essence, in sous vide, an item (usually a meat of some kind) is encased and vacuum sealed in a plastic bag, and cooked in a circulating water bath at the precise target cooking temperature for the ingredient. This gains a lot of the benefits of poaching, where the meat is cooked evenly, but then can be finished at high heat to get the benefits of caramelization. I hear (thanks, Chef MO), that whole birds are not amenable to sous vide because they don't hold up to the vacuum.

Vacuum sealing the ingredient maximizes even conduction of heat because there would be no air separating the heated water from the plastic sealed ingredient; the plastic bag prevents the water from dissolving and diluting compounds. One could attain some of the same benefits by poaching in a non-ionic liquid, like olive oil or clarified butter. And gain some additional ones with regards to flavoring. Problem is, this is expensive, and, let's face it, you're soaking your dish in warm oil for a long time.

In celebration of Thanksgiving, many have chosen the avenue of deep frying the turkey - but perhaps butter poaching the bird could be a less cumbersome dish. Problem will be the inordinate amount of butter required...or is it? Nathan Myhrvold reported that you don't really need all the butter in poaching - he got similar results when the butter is just brushed on after steaming certain fish.

So, here's my idea:

1. Take the turkey (dry brined). Be sure it is dry.
2. Coat it in butter. I envision brushing on layers of butter on the cold bird so that it solidifies like primer and paint.
3. Partially freeze the bird to get it cold on the outside.
4. Embed the bird in 1.5% agar. This would involve pouring 50C agar around the cold bird to get it completely encased in a block of agar, again, chilling to make sure that the agar is completely solid
5. Poach the whole block at 65C. The effect here is that the solid agar is the water, and the butter layer will liquify - but stay as a layer around the bird, effectively butter poaching the bird. The agar will remain solid at this temperature indefinitely.
6. After the appropriate period of poaching, allow the block to cool to handle, and break the block to release the bird; stick it in a high heat oven to brown. At this point, the bird should be mostly cooked, the skin should crisp up, and any bits of agar will melt off as the outside surfaces hit a temperature above 100C.

Leftover agar can be reused, of course. :)

2 comments:

  1. But... do you save money substituting agar for butter? I would think agar would be a *lot* more expensive than butter... Perhaps it's because I've never purchased food grade agar, just lab grade...

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  2. Food grade agar is VERY cheap. Agar has been consumed as a food for a very long time, much longer than it's been used as an electrophoretic gel matrix. Moreover, this whole experiment should take no more than a few grams of agar (10-20?), and can be remelted and reused again.

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