The nearly $8 billion dairy-alternatives market is expected to double in size over the next four years, thanks in part to the growing number of people avoiding cow's milk. But, even if former milk drinkers can get over the differences in taste, there's one front on which the almond, cashew and coconut cannot compete with the cow: protein.

That's the problem Adam Lowry and Neil Renninger — Silicon Valley-based scientists who previously founded Method cleaning products and Amyris Biotechnologies, respectively — set out to solve when they launched a line of Ripple Foods milks made not from nuts or soybeans, but from split yellow peas. Their goal: a plant-based milk that could rival the real deal in both nutrition and taste while using a fraction of the natural resources.

"Depending on the study, anywhere from 20 to 40 percent of carbon emissions globally come from the food system — and a quarter of all food emissions come from the dairy industry," says Renninger, an MIT-educated biochemical engineer. "If we could make a change here, we could have a massive impact."

Ripple's lineup of pea-based milks was the first of its kind when it hit the market in 2015. They milks are now available at 10,000 stores nationwide, including Kroger, Target and Whole Foods Market. The plant-based beverages boast 8 grams of protein per cup — the same as a cup of cow's milk — compared with 1 gram of protein in a cup of almond milk. Ripple's original milk also has half the sugar and twice as much calcium as a cup of 2-percent cow's milk.

The pea's nutritional punch has other dairy-alternative brands adding it to their recipes. WhiteWave Food's Silk brand launched a " protein nutmilk" in late 2016 that leans on peas for 10 grams of protein per serving while leaving other nuts in the mix. And Bolthouse Farms, owned by Campbell Soup Company, launched its own " plant protein milk" made from peas last year.

But Ripple's founders say they have something the others do not: a pea milk that leaves behind the legume's funky flavor. Their secret sauce is a patent-pending process that extracts the protein isolate from the pea without any of the taste that accompanies many plant-based proteins in their final products.

They call the flavorless, protein-packed ingredient " Ripptein" — and it could have uses far beyond the dairy section. Already, the company has expanded its offerings to include a creamy half-and-half and, this month, a Greek-style yogurt.

Renninger says they developed the technology while breaking down the parts that make up cow's milk — proteins, fats, sugars — and replicating them with plant sources in a lab. Those sources can often mimic milk while containing less fat and sugar, and many also have the protein needed to bond the disparate parts together. But there's more to the equation.

"The problem with most plant proteins is they taste like the plants they come from," Renninger says. Protein molecules, however, "are too big to hit the taste receptors on your tongue. Really, what we're tasting is not the protein; it's all the other stuff that's coming along for the ride."

Using a combination of pressure, temperature and salt, Renninger found a way to untangle the plant protein from its flavor-carrying parts. He describes it as a several-step process in which the protein molecule is mined from the others until it's all that remains.

The resulting protein powder is combined with ingredients such as sunflower oil, cane sugar, algal oil (for omega-3 fatty acids) and vitamins and minerals to create a beverage that resembles milk. In its lab, Ripple is working on recipes to take over more of the dairy aisle, with nutritional shakes, cheese and ice cream products.

"It's great for people who have to avoid cow's milk or nut-based milks like almond and cashew to be able to have another alternative for a beverage," says Alexia Beauregard, a registered dietitian who specializes in food allergies in Greenville, S.C.

But she cautions patients dealing with food allergies against seeing any one plant-based product as a cure-all for their sensitivities. Plant proteins, for example, are not considered "complete," meaning they do not contain the same combination of essential amino acids — those our bodies cannot produce on their own — as meat and eggs.

"Variety is the key to a healthy diet, no matter what diet," Beauregard adds.

Still, having a dairy alternative with eight times the protein of almond milk could be a boon for parents trying to funnel nutrition into their children with allergies or aversions — especially if it passes muster on taste. (In a taste test, three out of four editors at Cooking Light gave Ripple's original milk the green light.)

"We still have people who look at the product and think, 'Oh, milk from peas. I don't like peas,'" says Renninger, who says his two boys, ages 9 and 11, aren't fans of the green orbs but "guzzle" Ripple. "A lot of the marketing we've done is just to get people to try the product."

Though taste and nutrition are the deciding factors for most consumers, the pea has an impressive sustainability portfolio, too. Peas are good rotational crops for farmers that fix nitrogen into the soil and often can be grown without irrigation. Making milk from them uses six times less water than making milk from almonds, which are a water-intensive crop.

For Ripple, peas are just the beginning. The same protein-extraction process behind its milk could, for example, be used to turn waste products such as flaxseed meal and spent brewer's yeast into protein-rich ingredients.

"Having this really clean protein allows us a lot of space," Renninger says, "We can do a lot of things that haven't been done before."

Copyright 2018 NPR. To see more, visit