Rather, it’s a process increasingly used by food companies to answer a ballooning demand for natural ingredients that are hard to come by. Instead of sourcing these ingredients from nature, food scientists are creating them through an industrial method that they describe as similar to brewing beer.

Here’s how it works: Scientists identify the desired genes in a plant or animal and insert them into a host such as yeast. The yeast is fed sugars and nutrients to stimulate fermentation. Then the yeast and its genes are filtered off, and the desired ingredient is purified out of the remaining broth.

“Companies want to go more natural, but they’re running into constraints,” says Neil Goldsmith, CEO and co-founder of Evolva, which provides companies with the yeast for fermentation or runs the process for them. “Fermentation offers a way to make ingredients without being reliant on a challenged supply chain.”

Over at startup Perfect Day, the company is using fermentation to make cow’s milk without cows. They 3D-print the DNA sequence of a cow and insert it into a specific location of yeast—which they have aptly named Buttercup—obtained from the U.S. Department of Agriculture. The yeast ferments sugar to make real milk proteins (casein and whey), which are then combined with plant-based fats and nutrients to get milk that is lactose free.

The resulting milk is an answer for consumers concerned about the environmental and animal welfare impact of cow’s milk. Unlike plant-based alternatives, Perfect Day’s milk performs just like the stuff that comes from cows when making products like cheese and yogurt since both have the identical chemical composition. The company is working on commercialization and plans to go to market early next year.

Rendering courtesy of Perfect Day

Fermentation is also an integral tool for meat-alternative company Impossible Foods. It uses fermentation to make an essential ingredient in its plant-based products: heme, the molecule that makes meat taste like meat. Iron-rich, beet-colored heme is found in the roots of nitrogen-fixing plants, but Impossible Foods chose to make it via fermentation because it’s more economically feasible and environmentally friendly.

“We spent a long week in Minnesota and Texas digging in the fields,” explained Impossible Foods CEO and founder Pat Brown earlier this month. The problem? In turning the soil, they were releasing carbon into the atmosphere—an unintended consequence that countered their goal of creating a more sustainable product. Now instead they transfer genes from the soybean plant into the yeast, grow the yeast, and then isolate the heme protein from the resulting broth.

The process has also become a critical tool in the ongoing quest to find a natural, zero-calorie alternative to sugar. The sugar alcohol erythritol, for example, is found in some fruits but at such low levels that it makes more economic sense to make it through fermentation.

Meanwhile, Natur Research Ingredients has developed a product called Cweet made from the brazzein protein, which is 2,000 times sweeter than sugar and originates from the African Oubli plant. The company starts with the brazzein protein and molecule but produces it in higher volumes through fermentation.

“I believe that fermentation is one of the possible technology breakthroughs of being able to feed the global population,” says Natur Research Ingredients CEO Loren Miles. “We feel it’s more oriented to what the future demands are going to be for the world.”

Cargill is tackling the sugar problem by attempting to produce the sweetener stevia through fermentation. The compounds that give stevia its sweetness are called steviol glycosides, which make up only a fraction of the stevia leaf’s weight. The leaf contains more than 40 different kinds of glycosides, but some of the best tasting ones are also among the rarest so Cargill is producing them through fermentation.

Cargill’s product, called EverSweet, has been delayed because of production costs, but there’s also the looming question of whether consumers will accept the product as natural if it doesn’t come from a leaf—an issue that Cargill acknowledges. Concerns over consumer acceptance of fermentation is why food companies are quick to equate it with accessible and acceptable food processes like brewing beer or making bread. One advantage is that even though the yeast is genetically modified, the resulting ingredient is considered non-GMO since the yeast is filtered out and doesn’t end up in the final product.

As Fortune wrote, last month, this is the crux of the current dilemma. How does one engineer a natural solution?

Think of food companies’ plight this way: The finest scientists in industry have spent decades trying to find or invent a no-calorie sweetener that tastes and feels as good as the stuff extracted from pure cane. And now, after they largely failed to master that complex, arduous task, the level of difficulty is being raised even higher: This improbable concoction cannot appear to have been engineered by scientists.

The same principle applies to fermentation more broadly. It’s food science at its finest. Now companies just need to convince consumers, many of whom want technology nowhere near their food, that the process has nothing to do with science.