And some producers think it might make a good beverage.
Whey is an acidic liquid drained from conventional yogurt to create Greek yogurt.
"You produce the cream-top yogurt, just a pure traditional yogurt. And then you put it into these big nylon bags and you let them hang," explains Scott DiGuistini, co-owner of B.C.'s Tree Island Gourmet Yogurt.
"The whey drains out of the bags and you're left with the slightly green, watery, cloudy liquid, which is the whey. And then also a richer, creamier yogurt."
Even if you don't make your own yogurt, you've likely encountered whey. It usually puddles in your container after you leave it in the fridge for a day or two. Most of us stir the whey back into the yogurt.
The problem of whey
But the popularity of Greek yogurt means there is a lot of whey around these days. And it can't be dumped into municipal sewage systems, because it is so acidic it can affect the pH level in water systems, killing fish or contributing to algae blooms.
The alternative for some large manufacturers has been to produce Greek yogurt without draining whey. The thick texture is instead created using various additives.
Meanwhile, some manufacturers who use traditional methods of Greek yogurt production are hoping consumers might pay money for their by-product.
DiGuistini has made a sparkling beverage with whey. He's also made whey vodka, and even whey wine.
"I found it kind of heavy," he says of the wine. "We sparkled it. We tried different flavours."
But in the end, he says none of those products were tasty enough to actually sell to consumers.
For now, DiGuistini sends his whey to a nearby farm to be fed to animals. Large-scale Greek yogurt producers do the same, but they have to pay the farmers to take it.
Now, some producers in the United States have started selling plain whey by the litre, to be used in cooking. Some chefs brine meat in whey or use it to make smoothies or soup.
A whey forward?
But even DiGuistini isn't certain it would make for a popular beverage in Canada.
"You know, whether it'll turn into the next beverage trend, I'm cautiously optimistic. I feel like there is that possibility, which is why we keep playing with it. It's been tried before. At one point, it was launched into North America, and it failed."
That marketing failure was a product called Rivella, a popular whey-based soft drink in Switzerland and other parts of Europe. But attempts to introduce it to the mass market in North America haven't worked.
A Facebook group called "We Need Rivella Outside of Switzerland!" has been created, but so far has just over 200 "likes."