Curious Cook in the New York Times: Vodka in the fish fry

My column in today's New York Times Dining section is about a batter for fried fish developed at The Fat Duck, Heston Blumenthal's restaurant west of London. I first enjoyed the very crunchy crust it makes last spring, when Christopher Young, the restaurant's research manager--yes, they do enough research at The Fat Duck that it needs managing!--demonstrated it at the Greystone campus of the Culinary Institute of America. The key ingredient is alcohol. In an email, Chris explained how vodka ended up in a beer batter. Heston and his colleagues were doing a cookbook and TV series on popular British foods, and developing an updated recipe for fish and chips.

The story with the fish batter was that we had developed a really fantastic batter recipe using special starches from National Starch. By using these, along with the siphon to create a very irregular foam structure (an idea that based on the work of Julian Vincent at Bath University and the mechanics of brittle fracture) we created a really outstanding batter that would cook fast enough so that the fish wasn’t over cooked, but stay crisp for a good 20+ minutes. The only downside to this was that no one could recreate this batter at home.

We mostly dealt with this “pickle” by waiting for divine inspiration. That occurred one afternoon at my house when I was reducing alcohol for a sauce and while I had my back turned it boiled away to nothing. I was reminded that alcohol takes far less energy to evaporate than water. I thought it might be possible to reduce the amount of water in the batter by replacing it with alcohol and creating a batter that would cook faster. The added bonus was that alcohol destabilizes the foam, which creates a more inhomogenous structure, which makes the batter crisper!

There was a bit of trial and error, because you do need some gluten or the batter just “blows” off the fish. It seems that a final alcohol content of around 20% seems about right.

Inspiration favors the prepared mind!
For the other big advantage that alcohol brings to a batter, see my column. The Times also gives an adaptation of the Fat Duck's recipe for siphonless cooks.

Grass-Fed Beef vs. Farmed Salmon

My post last August about the weak claim of grass-fed beef to healthful quantities of omega-3 fatty acids has drawn a skeptical response from Robert Buxbaum, who found a contrary view in Michael Pollan's important new book, The Omnivore's Dilemma. I'd like to dissect the discussion a bit, because I think it's a cautionary example of how easily speculations about food and nutrition can stray from the facts, become accepted as fact themselves, and end up being unintentionally misleading.

For context: I've long been a believer in the importance of local, small-scale, sustainable food production, greatly admired Michael Pollan's address in the moving opening ceremonies at Terra Madre last month, and have been a fan ever since reading his 1991 book Second Nature.

Bux wrote:
I have some comments and a question about your August 25 report on
omega-3 fatty acids in grass-fed beef. Are you comparing farm raised
salmon or wild salmon when comparing grass-fed beef to salmon? As I
posted on [Michael] Ruhlman's blog: Pollan, in "The Omnivore's Dilemma,"
mentioned that our impression of salmon as superior to beef as a
source of omega 3 fatty acids was based on measurements taken at the
time in which we first became conscious of omega 3s. That was when
most available beef was corn fed and most salmon was wild. Pollan
further claims that grass fed beef is a better source omega 3s than
farmed salmon, which is what most consumers eat now.
It seems as if how the salmon, as well as the cattle, are raised is significant in
each case.

What Michael Pollan does say on pp. 268-269 of his book is that, like industrial cattle, farmed salmon are fed on grain, and they therefore contain less omega-3s than wild salmon, which eat small creatures that have accumulated omega-3s from the oceanic equivalent of grass, the tiny phytoplankton. He then speculates (my italics) that "if the steer is fattened on grass and the salmon on grain, we might actually be better off eating the beef," and that "the species of animal you eat may matter less than what the animal you're eating has itself eaten."

In fact, farmed salmon are primarily raised not on grain but on fish meal, a feed which is problematic in its own way, but which is plenty rich in omega-3s. A thorough survey published in 2005 found that salmon farmed in various regions throughout the world have consistently higher omega-3 levels than wild salmon, mainly because they are consistently fattier. And beef? The long-chain omega-3s in grassfed beef are present at around 20 milligrams per 100 grams (about a quarter-pound) of beef. The levels in farmed salmon are around 3 grams per 100 grams of fish: more than a hundredfold higher. Even salmon raised experimentally on vegetable oil for three-quarters of their life (to begin to address the issue of sustainability) have 1 gram of omega-3s per 100 grams fish: 50 times more than grass-fed beef. These are huge differences!

So species matters a lot. Ocean-going creatures live in a cold environment and need highly unsaturated fats that won't congeal at temperatures that can approach the freezing point; mammals are warm-blooded and need saturated fats that won't be too fluid at body temperature. Even grass-fed beef still comes from a warm-blooded steer, and farmed salmon is still a cold-blooded fish. And when it comes to the highly unsaturated omega-3s, we're far better off eating salmon.

Of course this is just one small piece of a large and complicated picture. There is plenty to be said in favor of grass-fed beef, plenty of problems with salmon aquaculture, and there's more to a healthy diet than omega-3s, which we can also get from other fish and shellfish. But it's good to have each piece of the picture in the right place, right-side up, however small it is.

Hamilton, M.C. et al. Lipid Composition and Contaminants in Farmed and Wild Salmon. Environ. Sci. Technol. 2005, 39, 8622-8629.
Torstensen, B.E. et al. Tailoring of Atlantic salmon (Salmo salar L.) flesh lipid composition and sensory quality by replacing fish oil with a vegetable oil blend. J. Agric. Food Chem. 2005; 53:10166-78.