These days, Greek yogurt is hugely popular. But it also poses a problem: what to do with that leftover whey?
About a year ago, I decided to try and make my own cheese. I opted for an easy one – cream cheese – and chronicled it on my blog. Figuring that I ought to start with high quality ingredients, I got about a gallon of the best non-homogenized organic whole milk I could afford - and set to work. A day later, I had a pint and a half of cream cheese and six and a half pints of whey.
This is similar to the dilemma the Greek yogurt industry now faces. So-called “Greek” yogurt is nothing more than yogurt with the whey removed. (Greeks don’t have a monopoly on eating yogurt minus whey, but it would not behoove marketers to change their winning brand based on accuracy at this point.) With two to three ounces of whey for every ounce of Greek yogurt produced, the industry faces a challenge to dispose of all that whey.
Rigutto compares it to manure. She produces whey in small quantities as she needs it, just as her horses, goats, and chickens produce just as much manure as she requires to fertilize her soil organically. “I know how much manure I need, so that's how much livestock I have, and that works. If I had too many animals on the farm, then the manure becomes a problem and not an asset.” You might not like to think of food product as something comparable to manure, but both are nutrient dense and useful, but toxic when produced in excessive quantities.
To start, what is whey? Milk is an incredibly complex food, but it can be easily separated into three parts.
After it leaves the cow, if you let the milk sit, the cream will rise to the top. You can skim this off to use as cream, or you can turn it into whipped cream or even butter. The fat-free milk that remains, of course, is what we know as skim milk. The dairy industry generally removes the butterfat from the milk via centrifuge and then adds it back in to make one percent, two percent, and “whole” milk. And while the “whole” milk found in stores contains 3.25 percent butterfat, that’s not how it comes out of the cow. Cows vary in the amount of butterfat in their milk, with the favorite industrial breed, the Holstein, producing a lower percentage than some other dairy breeds like Jerseys.
But aside from separating out the butterfat, you can also separate the curds from the whey. Either starting with skim milk or whole milk, add a bit of lemon juice and the milk solids will curdle, separating out from a cloudy liquid called whey. Strain the curdled milk with a cheesecloth to fully separate the curds (the solids) from the whey. This is how you make the paneer cheese found in Indian food.
Separating curds from whey is a key part of making cheese. Paneer is not technically cheese, as no cultures were added and no fermentation takes place. Cheesemaking – and yogurt making – requires heating the milk to a specified temperature, adding cultures, and holding the milk at that temperature for a period of time. To make yogurt, heat the milk to 180F and then cool it to 115F before adding the cultures. Some recipes recommend holding it around that temperature for longer periods, but I find that keeping it between 105 and 115 for four hours generally does the trick.
For cheese, you add a substance called rennet – an enzyme typically taken from the stomach of a calf, although now vegetarian options are available – to induce curdling. Once the cultures have done their job, most cheeses require straining through a cheesecloth to separate the curds from the whey.
Yogurt’s a different story. Even if you never plan to make your own cheese, you can separate the curds from the whey with store-bought yogurt at home. This is all that the product sold as Greek yogurt actually is. Strain any kind of yogurt through a cheesecloth and the whey will drip out, leaving behind what some believe is a creamier and healthier product for you to eat.
The notion that Greek yogurt is healthier than normal yogurt comes from the fact that Greek yogurt is a more concentrated product with the whey removed. Compared to plain yogurt, one cup of Greek yogurt contains more protein, fewer carbs, and less lactose. Therefore, if you don’t tolerate lactose well, or if you subscribe to the notion that all carbs are the devil and protein is the most valuable macronutrient around, Greek yogurt is for you.
The runaway marketing success of Greek yogurt has left manufacturers with a problem on their hands: what to do with all of that whey. The very same problem I faced after my first bold steps into the world of cheesemaking.
But whey, while watery, is not the nutritional equivalent of water. Yes, it contains some of the lactose from milk, but it’s also rich in calcium and other nutrients, not to mention beneficial microbes. Whey, it turns out, is useful.
For one thing, you can use whey to make your own ricotta cheese. Ricotta is simply the Italian word for “recooked.” First, you make cheese or yogurt. Then you take what’s leftover – whey – and “recook” it into ricotta. Recipes that specifically call for whey drained from yogurt are available online.
When looking for a way to put my own whey to good use, I turned to a few friends and a few websites for help. One friend gave me a cookbook called Nourishing Traditionsby Sally Fallon and Mary Enig, as it contained several recipes calling for whey. Fallon and Enig often recommend soaking grains overnight prior to using them to break down an antinutrient in them called phytic acid. You can help this process along by adding a bit of whey to the soak water. A nice bonus is that whole grains like steel cut oats and brown rice cook faster following soaking. You can add whey when you soak beans too.
Farmer Joanne Rigutto contributed more tips for using whey. When she’s in a “cheesy mood,” she makes a few pounds paneer cheese per week, yielding about three quarters of a gallon of whey per pound of cheese. “If I’m eating soup all the time and doing a lot of stews and whatnot,” she says, “it will take me anywhere from one big stews to four to five days to use all that up.”
She replaces water in her recipes with whey for soups, stews, breads, muffins, cornbread, and more. “If you make pancakes, if you use whey instead of water, it will produce the lightest fluffiest pancakes you’ve ever had.”
“Anywhere you use water,” she continues, “it adds a little extra flavor. It adds umami.” That’s the fifth flavor, named for the Japanese word meaning deliciousness. “You can't really taste that it's whey but it enhances the flavor to everything.” Rigutto used to use wine in her cooking, but found she could now use whey instead. “It’s cheaper than using wine for one thing, and if you’re making cheese, you’re gonna have the whey anyway.”
She also feeds whey to her animals. “I just started malting barley for beer-making and because I have enough animals right now, I can brew beer all the time and I’ll have animal feeds from the spent grains. I’m going to start milking the goats here soon too, which means I’m going to be making cheese on a regular basis.” She then mixes the whey with her spent beer grains and feeds it to the chickens and – in small quantities – to the horses. When she gets pigs, they will receive spent grains and whey too.
“When you’re making cheese,” she summarizes, “You’re pulling out the protein mostly. So the whey has all the other good things.” Using the whey is “just another way to get the squeal out of the pig.”
In other words, if you’d like to help Greek yogurt makers with their pollution problem, a simple way to do so is by depriving them of your business. Opt for regular yogurt instead and using the whey yourself.
(And if you’re feeling brave and you try making yogurt at home, here’s some advice from my yogurt-making exploits: don’t give up if it does not work the first time. Yogurt is very easy to make, but it’s also easy to screw up. I’ve done so by using dead cultures instead of live ones, by attempting to make yogurt in a metal pot that was too conductive and cooked the cultures, and by using a broken thermometer without realizing it wasn’t working. But if so long as you use live cultures and keep the milk at the right temperature, it’s a cinch.)