Cooking for Geeks: Real Science, Great Hacks, and Good Food (64 page)
Read Cooking for Geeks: Real Science, Great Hacks, and Good Food Online
Authors: Jeff Potter
Tags: #COOKING / Methods / General
Since transglutaminase binds proteins at the molecular level, you can also use it as a binder to form ground meats into a solid form (Spam!). Imagine taking wood glue and, instead of gluing two boards together, using the glue to re-form a piece of wood from sawdust. Yes, just like particleboard or chipboard. The next recipe demonstrates this concept.
Purée with an immersion blender or food processor:
- 175g shrimp, raw, peeled, and deveined
- 50g water
- 10g transglutaminase
Transfer the purée to the center of a large sheet of parchment paper. Using a spatula, fan out the purée so that it’s flat enough to place a second piece of parchment paper on top of it. Using a rolling pin, roll the purée out to a thickness of ⅛” / 0.3 cm, just as you would for a pie crust dough. Transfer the “sandwiched” purée to the fridge and let rest for a minimum two hours, preferably overnight.
In a large pot, bring salted water to a rolling boil.
Fill a large bowl with ice water.
Using a sharp chef’s knife, cut a portion of the sandwiched purée down to a size that will fit in your pot. Carefully slip the sheet into the boiling water. The parchment paper should detach from the shrimp purée; this is expected. After 30 seconds to a minute, use a spider (or slotted spoon and tongs, if you’re careful) to fish out the shrimp sheet from the boiling water, and transfer it to the ice water bath to stop the cooking process.
You should now have a “sheet” of shrimp that you can slice into noodles or use as a wrap around food items. To make shrimp noodles, slice the shrimp sheet into thin slices, which can then be floated in seafood broth or tossed with seared tofu, sesame seeds, sautéed green onions, and soy sauce. Or, try making “reverse sushi,” using the shrimp sheet as the wrapper for the rice in place of the customary nori seaweed wrapper.
You can use rubber bands on the edges of your rolling pin to achieve a consistent thickness. This photo shows the shrimp and transglutaminase purée sandwiched in parchment paper.
A spider is a handy tool for fetching delicate items from boiling water. Note that the shrimp noodles and parchment paper have separated in the boiling water.
Smoking — burning wood chips and directing either the hot or cold smoke vapors to come in contact with items such as meats — is a method for curing and preserving foods. Smoking also deposits a number of flavors onto the food that are generated as byproducts of the chemical reactions that occur when wood is combusted. The commercial food industry uses liquid smoke to infuse smoke flavor into foods that are traditionally smoked, such as bacon, and into foods for which the flavor is enhanced by smoke essence, such as “smoked” tofu.
The simplest way of creating a smoked flavor in your cooking — besides actually smoking it — is to include ingredients that are already smoked and contain those chemical compounds. You can infuse smoke flavors into your dish by adding spices such as chipotle peppers or smoked paprika, or by using dry rubs with smoked teas such as Lapsang Souchong. Tobacco, too, can be used to similar effect; some novel restaurant dishes include components like tobacco-infused crème anglaise. However, including smoked ingredients will also bring along the other flavors of the substance being used. Some dishes can use smoked salts, for example, but for many applications, this will contribute too much salt. This is where liquid smoke comes in.
A cook can use liquid smoke to highlight the smoky “toasted” flavors of foods, especially those that have similar molecular compounds to smoke, such as coffee, peanut butter, or Scotch whisky. You can also use it to impart smoke flavor in those situations where grilling isn’t an option — say, on the 27th floor of your apartment complex.
When buying liquid smoke, look for an ingredient list that reads “smoke, water.” Try to avoid products that have molasses or other additives.
Some of the more unusual uses allow for bringing smoked flavor to foods that can’t normally be tossed onto a wood-burning grill, such as tofu, ice cream, or liquids (along with some sandalwood incense and Chanel N°5, if you’re Maggie from
Northern Exposure)
. Butter also has some of the same phenols as smoke; try adding it to butter for table service with bread.
The big long evil list of nasty chemicals and ingredients that one would expect to see on a liquid smoke bottle? “Water, smoke.” In and of itself, liquid smoke is not artificial. It does not undergo any chemical modifications or refining steps that alter or change the compounds that would have been present in traditional smoking.
In theory, some of the mutagenic compounds (those that cause cancer) normally present in traditionally smoked foods are present in much smaller quantities in liquid smoke, meaning that liquid smoke might actually be somewhat safer for you than traditionally smoked foods. However, be aware that liquid smoke will have some amount of mutagenic compounds present. As a substitute for smoking foods, it should be as safe as traditional smoking, but you probably shouldn’t douse a teaspoon of it on your morning eggs every day until further research is done.
In addition to the following two recipes, consider revisiting the Salmon Gravlax recipe from earlier in this chapter (see
Salmon Gravlax
) and adding liquid smoke to give it a cold-smoked flavor.
This recipe uses liquid smoke to impart the toasted flavor of campfire-roasted marshmallows. The concept was inspired by a demo by Kent Kirshenbaum of NYU’s Experimental Cuisine Collective.
You’ll need a standard ice cream mixer, or you can go all-out geek and either make your own (see
DIY Lego Ice Cream Maker
in
Chapter 3
) or use liquid nitrogen or dry ice. For the latter options, see the instructions in
Making ice cream
in
Chapter 7
.
To create the base, combine in a mixing bowl:
- 2 cups (475g) whole milk
- 1 cup (238g) heavy cream
- ⅓ cup (75g) sugar
- ¼ cup (75g) chocolate syrup
- ¾ cup (25g) medium-sized marshmallows
- 15 drops (0.75g) liquid smoke
Proceed with the directions for your chosen method of making ice cream. Once the ice cream has set, stir in:
- 1 cup (60g) graham crackers, toasted and chopped into pieces
Serve with hot fudge or chocolate syrup — whipped cream, cherries, and nuts optional.
In a large baking pan (9” × 13” / 23 cm × 33 cm), place:
- 2 pounds (1kg) pork baby back ribs, excess fat trimmed off
In a small bowl, create a dry rub by mixing:
- 1 tablespoon (15g) salt
- 1 tablespoon (15g) brown sugar
- 1 tablespoon (9g) cumin seed
- 1 tablespoon (9g) mustard seed
- 20 drops (1g) liquid smoke
Cover ribs with spice mix. Cover baking pan with foil and bake at 300°F / 150°C for two hours.
In a small bowl, create a sauce by mixing:
- 4 tablespoons (60g) ketchup
- 1 tablespoon (15g) soy sauce
- 1 tablespoon (15g) brown sugar
- 1 teaspoon (5g) Worcestershire sauce
Remove foil from baking pan and coat ribs with sauce. Bake for 45 minutes, or until done.
Note
- Experiment with other savory spices in the dry rub, such as chilies, garlic, or paprika. Also, try adding items such as onions, garlic, or Tabasco to the sauce.
The smells that we associate with that smoky, barbeque goodness result solely from the chemical reactions that occur during pyrolyzation (burning) of wood. The flavor that you think of as “smoky” does not come from a chemical interaction between the food and the smoke. This lucky quirk means that the chemicals in smoke can be isolated, so the stage of generating smoke flavor can be separated from the step of applying that flavor to food.
You can make your own liquid smoke for about $20 worth of supplies and a few hours of your time. For day-to-day uses, you’re way better off buying liquid smoke from the grocery store, but it’s rewarding to see how straightforward it is to make, and the process touches on some elementary chemistry techniques as well.
Liquid smoke is made by heating wood chips to a temperature high enough for the lignins in wood to burn, condensing the resulting smoke, and then dissolving it in water. The water-soluble components of smoke remain dissolved in the water, while the non-water-soluble components either precipitate out or form an oil layer that is then discarded. The resulting product is an amber-tinted liquid that you can brush onto meats or mix in with your ingredients.
What actually happens when you burn wood? Wood is primarily made of cellulose, hemicellulose, and lignin, which during burning convert to several hundred different chemical compounds. The aromatic molecules that provide smoke flavoring are generated by the lignin, which breaks down at around 752°F / 400°C. Cellulose and hemicellulose break down at lower temperatures (480–570°F / 250–300°C), but they generate compounds that both detract from the flavor and are mutagenic. This is why, when grilling, you should make sure you have a hot fire, which will guarantee that the lignins, and not just the celluloses, break down.
Making your own liquid smoke can be a little tricky because of the high heat required to properly burn the lignins and the difficulty in correctly capturing the resulting lignin-based compounds, not to mention the need for proper chemistry lab equipment for creating a closed system and heating it safely.
Kent Kirshenbaum demonstrates making liquid smoke during a talk at NYU’s Experimental Cuisine Collective (see
http://www.experimentalcuisine.org
). Here, he burns hickory chips using a propane blowtorch. The smoke is then piped through a water flask (on right), which traps the water-soluble particulate in suspension.
Start by placing wood chips — either hickory or cedar — into a vessel that can be sealed (to create a closed system) and heated with a burner or blow torch. Run a line from the closed system into a container of water, so as to filter the smoke vapor through the water. Heat the vessel, making sure to get it hot enough for the lignins to burn. Because the “tasty molecules” of the smoke are water soluble, the water will end up capturing those flavors, becoming your liquid smoke. Discard any solids that precipitate out or oils that separate and float to the top. Theoretically, something like this could be done with a pipe on a charcoal grill, with the pipe sealed on one end and copper tubing running from the other end into a water container, but it’s definitely not up to lab safety protocols.
If you do manage to make your own liquid smoke — it does make for a fun experiment — you’ll probably find that it’s a lot more work than it’s worth. Still, understanding that liquid smoke is nothing more than smoke particles captured in water removes most of the mystery about what’s in the bottle at your grocery store.