Welcome to Ask Dave Arnold, a new regular feature in which David Arnold, director of technology at the French Culinary Institute, provides in-depth answers to reader questions on food science, cooking technique, and other issues. If you'd like to send in a query, do e-mail it in. To this week's batch:
[Original artwork by Eric Lebofsky]
Question One: What are some new techniques or devices you're developing?
Dave Arnold: I am starting a new company, tentatively titled Dax and Booker LLC, backed by Momofuku and my buddy Dave Chang. I intend to develop a slew of new cooking devices over the next few years, both for restaurant kitchens and for homes. I could tell you about them, but Dave Chang would find and kill all of you. In the meantime, I will say that we just acquired a ZCorp 3-d printer which hopefully will let me churn out prototypes at a ferocious rate when we get started a couple months from now. Aside from prototypes the Zcorp can print plaster which can be vacuum impregnated with vitreous slip to make custom plates for events. An interesting idea I'm looking forward to testing.
I have a few techniques I haven't blogged about on Cooking Issues yet. One is the newest lime-juice clarification technique. Using the wine-fining agents Chitosan (a non-vegetarian hydrocolloid) and Kieselsol (a silica suspension), both of which you can purchase at homebrew shops, I can clarify any citrus juice without using heat in 1 hour 15 minutes flat with an 85-95% yield. Downside: you need a centrifuge (go buy one already). I hope to explain it soon.
Question Two: I just bought a new Polyscience circulator and am having a barbecue on Saturday for 30. Can you recommend a good summer dish where I can utilize both the circulator and the grill?
Dave Arnold: Here is what I would do. Get a bunch of Ziploc bags and put some melted butter in them. Take some thick rib steaks, pepper them but don't salt them yet. In the kitchen, get a pan screaming hot and sear the steaks 1 minute on a side. Put them into the Ziploc using these instructions from Cooking Issues. Cook the steaks at 55?C (131?F) for between 1.5 and 3 hours. You can cool them at this point if you wish and re-warm later (at 50?-52? C for 30 minutes to 1.5 hours), or if you are going to use them in the next hour and a half, just turn your circulator down to 50?C (126?F) and wait for the temperature to drop. Now salt and sear your steaks on the hottest grill you can muster (intensely hot, like the surface of the sun) for 1-1.5 minutes per side.
Almost as good as a vacuum.
This technique is fantastic for several reasons:
· You will never over or undercook a steak again. Ever.
· Steaks cooked this way are absurdly delicious.
· Even though you have more work at prep time your steaks are finished in only 2 or 3 minutes, so you can enjoy your guests.
· If your guests are late or don't sit down when they are supposed to, the steaks stay perfect, just waiting to be seared.
· If you add garlic to the butter in the ziplocs it makes awesome garlic bread.
Explaining the technique: The reason I don't salt the meat before the first sear is that, if the steak isn't going to be served within a couple of hours, salt will cure the meat, changing its texture. I then sear before I cook in the circulator to kill bacteria and start developing flavor. Bagging in the Ziploc means I don't need a vacuum machine and I can bag my steaks while they are warm. The reason I drop the temperature after I cook them is so I won't overcook the steaks when I am searing the second time.
Note: 50?C isn't a safe temperature to hold meat for a long time.
This same technique works for zillions of foods: thick hamburgers 55.5?C (make sure you cook them for at least 20 hours because ground meat is less safe than steak and needs more time to kill the bacteria) or chicken breasts at 63?C (146?F) for an hour.
Question Three: What is the best way to make hard liquor ice pops (ie: rum) without diluting too much?
Dave Arnold: Cocktails never make really good popsicles. They never freeze right, as they are soft and melt very quickly. Alco-pops are hindered a double whammy of alcohol and sugar: two ingredients that lower the freezing point of water and make your pop melt quickly. In fact, popsicles typically have a lot of sugar, because your perception of flavors, including sweetness, is reduced at low temperatures.
Typical solution: Make your popsicles very weak in sugar, or alcohol, or both. This is clearly an unacceptable solution. Remember, because you are freezing your mix, the flavors need to be bold, not weak. Lowering the sugar (unless you are making a dry martini-sicle) isn't the way to go. Even if you use no sugar at all, a good stiff martini clocking in at 20% alcohol just won't freeze well. Your question, as stated, is: how do we make a stiff drink-sicle?
Unacceptable solution number two: Make your popsicles really, really cold. I have no problem taking straight gin and freezing it solid like a rock with liquid nitrogen or dry ice, but popsicles made this way will severely hurt your tongue. I have been served liquid nitrogen alcohol sorbets that have burned my tongue so I couldn't taste for the rest of the night. Your pain threshold for cold 80 proof vodka is about -20?C (-4?F). Mixed drinks have an even higher pain threshold temperature because they contain more water, which packs a bigger cold wallop on your tongue. To get a really solid margarita-sicle at around 18-20% alcohol you would have to freeze down far below that -20?C (-4?F) pain threshold.
Better Solution: Homemade slow-melt pops. Slow melting popsicles contain gelatin. The gelatin is actually broken by the freezing process (so you wont just be sucking on cold jello, you'll get liquid), but it will maintain enough of a structure to inhibit melting. I haven't tested these, but for ratios, I would keep the total alcohol content of your mix around 15 percent to start (go higher if you have success), and use one pack of Knox unflavored gelatin (0.25 ounces) to about 4 cups liquid. Dissolve the Knox in hot water and add your booze to that. Freeze and enjoy. You can add more gelatin if you need to. If you are a vegetarian, you can try using agar-agar powder (a seaweed derivative you can get at Asian grocery stores) at a ratio of 3-4 grams per liter (sorry, I do agar in metric). PS, the agar should be added to cold water and simmered for 2 minutes before adding sugar, flavor, and alcohol.
See you in two weeks. Have questions for Dave? Send them in.
And for more answers to your cooking issues, tune into Dave Arnold every Tuesday at noon on the Heritage Radio Network