Nondairy milk isn't just for hippies and vegans—though, would it be so wrong if it were?—and it's gone through waves of appreciation and admonition among baristas and coffee snobs alike. Far from being the worst thing you can add to your coffee (I'm looking at you, Splenda), nondairy milk is actually pretty fascinating stuff, and it can be totally delicious in its own right.
Here are five handy facts about nondairy milk.
Soy will never, ever be as "foamy" as milk.
I'm sorry to burst your cappuccino bubble here, but the chemistry that allows cow's milk to create such beautiful, lasting microfoam simply isn't the same in nondairy milks of all types.
Dairy milk captures and suspends air bubbles so well because of the interaction between proteins and lipids that occurs via heat application. Surfactants created by denaturing of these compounds during heating allow them to bond with each other, creating a network that holds bubbles—also introduced via the steam wand—in place within the liquid base of the milk. (That might be the geekiest-sounding paragraph I've ever written about coffee.)
While there are still proteins to denature in soy (and almond) milk, the liquid tends not to have the same ability to emulsify the air bubbles for a frothy texture throughout: Different extraction methods applied to the soybeans themselves can affect the content of polar lipids in the drink, which are what's necessary for foaming. Additionally, the higher water content in soy milk means that the hydrophilic ends of the polar protein groups are overwhelmed, and additives to temper this process tend to create a less-than-perfect finished foamed result. (Okay, actually that might be the geekiest-sounding paragraph.)
Getting cross-eyed? Don't worry: Just accept that your soy cappuccino might be less "cap" and more "-ino," and go ahead and enjoy it anyway.
You can, however, make nice-looking lattes with it.
It just takes a little practice.
This soy milk has gone bad—or has it?
You know that awful thing when you pour soy milk into your cup of drip coffee and the whole mess turns to, like, roiling curds of nastiness?
Don't worry: It's not that the soy milk has turned, I promise. (Go ahead: Smell it. It's fine.)
What's happening is the acids in the coffee are coagulating the proteins in the soy milk, a kind of liquid-to-solid chemical reaction that can be exacerbated by the shock of the temperature difference between the two beverages. (Hot coffee, cold milk = Clots in the cup.)
Heating the soy milk will likely only result in more coagulation, but allowing the coffee to cool slightly seems to temper the effects. Vigorously shaking the soy milk before pouring can also help (but make sure the cap's on that thing before shaking). Many brands of soy milk have also added stabilizers to prevent this from happening.
Nondairy milk is really easy to make at home.
Making nondairy milk is actually a cinch: All you'll need are the nuts or seeds you'd like to use, some fresh water, a tiny bit of salt if you like, a blender or food processor, and something to strain with. I love making sunflower seed milk, but any seed or nut will do: cashews, almonds, soybeans, pepitas, hazelnuts, you name it.
Simply soak 1 cup of the (washed, raw) seeds or nuts for about 12 hours in just enough water to cover them. Drain the seeds, and blend them with a dash of salt and 3 cups of fresh water until fully smooth. Sweeten it, if you like. A little honey is nice.
You can drain the pulp from the liquid for a smoother milk by using a cheesecloth, fine-mesh sieve, or nut-milk bag (tee hee), which are available at most grocery stores. Don't toss the pulp, either: It's great spread on crackers or toast, and can be used to make all kinds of baked goods, spreads, or vegan cheese-like things.
Almond milk is on the rise.
Almond milk is quickly replacing soy as the standard (or only!) nondairy offering in cafés all over (e.g. San Francisco's Four Barrel), for several reasons, typically including digestion difficulties and allergies some folks have with soy; the fact that most soy milks have many, many unpronounceable additives and loads of sugar in them; concerns over the GMO weirdness of soybeans in the United States; and logistical problems concerning texture and steaming on the espresso bar.
Oh, and maybe most important of all? Almond milk tastes totally awesome. Once you go nuts, you may never...go...back to soy, I guess?
Do you have a favorite nondairy milk for coffee?