Lab-grown meat. Cultured meat. Cell-based meat. Clean meat. It’s all the same thing: meat grown from just a few cells from an actual animal. And although it’s years away from your supermarket, its potential to radically change animal agriculture as we know it is stirring up tensions.

At the urging of traditional meat producers, Missouri passed a law in May prohibiting anything not “derived from harvested production livestock or poultry“ from being marketed as “meat” in the state. This week, advocates of lab-based meat sued, alleging freedom of speech infringement, just before the law went into effect on Tuesday.

While the Missouri law covers both imitation meats — like the Beyond Burger and Impossible Burger, which get their protein from plants — and lab-grown meat, they are not the same. Lab-grown meat is animal tissue, grown in a tank by putting a few cells in a growth medium and letting them reproduce. No plants.

The lab-grown startups and their supporters believe that their products can one day make cows, pigs, and chickens — and even fish — obsolete. Memphis Meats, Just, Finless Foods, SuperMeat (in Israel), and Mosa Meat (in the Netherlands) are a few of the companies working on it. Nonprofits like the Good Food Institute and New Harvest are working to help fund them.

And they have a compelling argument. If you could grow enough meat in a lab to satisfy at least some of the world’s meat demand, and if you could solve all the problems of animal welfare and environmental impact while you’re at it, why on earth wouldn’t you?

But don’t fire up the grill just yet. Between what we have now and a lab-grown chicken in every pot, there is quite a ways to go.

There’s no consensus on what to call the stuff, and it’s high time we figured it out, since some of the companies involved claim that they’re close to bringing a hamburger- or sausage-like product to market, although it may be in a very limited way. The company Just, for example, plans to release lab-grown chicken by the end of the year, in restaurants outside the US.

For this piece, I’m going with “lab-grown meat” because it seems to be a reasonable description of the process.

How to grow meat in a lab

Lab-grown meat starts with cells — you can use stem cells, muscle cells, fat cells, myo- or fibroblasts — that you submerge in a growth medium. The medium is “a soup of nutrients that mimics what happens in the animal’s body,” explains Vitor Santo, a senior scientist with Just (formerly Hampton Creek, the company that brought you plant-based Just Mayo).

Depending on the type of cells and the medium ingredients, you can grow different kinds of tissue. Muscle cells grow more muscle cells, fat cells grow more fat cells; both are in meat as we know it. Stem cells can be coaxed into growing different kinds of tissue.

There’s one more element beyond cells and soup: scaffolding. The cells need something to grow on. If the scaffolding is going to be part of the eventual product (as it would if you’re growing a whole muscle meat like a steak or a chicken breast), then it obviously has to be edible. If the meat gets removed from the scaffold, as it would if the product was more like ground meat, then it just has to be safe.

That’s the simplified version of a process that, in practice, is complex and tightly controlled. It all takes place in what’s called a bioreactor — a tank where you can control the temperature, pH, oxygen levels, and a host of other factors. Right now, Santo is working with 2-liter tanks, and one of the big questions of clean meat is how scalable the process is.

According to Ben Wurgaft, a historian working on a book about lab-grown meat, there are some significant challenges involved. First is sourcing the proteins, vitamins, sugars, and hormones that go into that medium without using serum from the blood of those actual animals, which would at least partially defeat the purpose of lab-grown meat and would certainly be cost-prohibitive. Second is creating bioreactors that are “vascularized,” or have the infrastructure to deliver serum to cells at the center of a piece of meat, as blood vessels do to animal cells. Without that, you can’t grow the thick tissue necessary for steak or chicken breast (although you can still grow the equivalent of ground meats).

“If those don’t turn out to be easier nuts to crack than they seem to be so far, we will not see cultured meat emerging at the time scale of companies and venture capitalists,” Wurgaft says — which is to say, soon.

There’s one advantage to a longer timeline: It gives our regulatory agencies, industry groups, and various other stakeholders time to sort out the politics.

Who will watch the henhouse?

The US Department of Agriculture has oversight on the kind of meat that involves farms and slaughterhouses. There are factions within the meat industry that want lab-grown meat to come under the jurisdiction of the agency, where they have longstanding relationships and some influence. The other choice is the Food and Drug Administration, and commissioner Scott Gottlieb staked a claim to the territory at a public hearing held in July, arguing that their “past experience with novel food technologies” and “extensive background in cell-cultured technologies” makes the FDA well-suited to the job. “It’s not our first rodeo,” added Susan Mayne, director of the FDA’s Center for Food Safety and Applied Nutrition.

One possible outcome, which the lab-grown meat company Memphis Meats and the North American Meat Association, a traditional meat industry group, pushed in a recent letter, is that the two agencies will split responsibility. As a USDA spokesperson told me, “As these new products begin to emerge in the marketplace, we look forward to working with the FDA and the public to tackle these issues.”

As for just what the agency — whichever one it is — will be regulating, “The questions are not different from other types of food,” says Greg Jaffe, the biotechnology director for the Center for Science in the Public Interest. You have to make sure there are no allergens in the scaffolding, and that hormone levels are comparable to those of traditional meat. (The various aspects of safety regulation were discussed at length by FDA officials and a variety of other stakeholders, including Jaffe, at the July hearing, and the transcript provides a comprehensive look at the regulatory challenges.)

Settling this in advance is a good thing, says Jaffe. The fact that a viable product is years away gives everyone involved the chance to get ahead of it. And the industry is asking for regulation, knowing that oversight will be critical to consumer acceptance.

There’s one big regulatory issue that has nothing to do with safety: what we’re supposed to call it. Bruce Friedrich, founder and executive director of the Good Food Institute, a nonprofit supporting plant-based and lab-grown meat, likes “clean meat.” Memphis Meats, another one of the startups, goes with “cell-based.” Josh Tetrick, the CEO of Just, likes plain old “meat.”

Tetrick is an outlier, as most people want a way to distinguish lab-grown meat from field-grown meat. And while some meat industry groups (like the US Cattlemen’s Association) oppose the use of the word “meat,” others (like the North American Meat Institute) have argued specifically that the lab-grown products meet the USDA’s definition of meat — part of their bid for at least partial USDA oversight. The variety of interest groups involved in the decision, and the fate of state efforts like the Missouri law, all muddy the waters.

Will it matter? How will consumers react?

Lab-grown meat makers claim their products will taste exactly like the real thing because they are the real thing. That leaves consumers to make their decision on factors other than taste, and lab-grown meat definitely has advantages.

Some are obvious, like the animal welfare issue. Take the animal out of the equation and the welfare problems go with it. No more slaughterhouses, no more caging, crating, and crowding animals, no more (rare) cases of outright abuse.

Then there’s the issue of foodborne illnesses. Since the meat is grown in a closed vessel in a sterile environment — as opposed to, say, a barn — the hope is that there would be much less chance for pathogens to sneak in. That’s relevant for antibiotics, too. Although the drugs can theoretically be used in the lab-grown process, a sterile environment shouldn’t require them, and so the issue of antibiotic-resistant bacteria goes away.

Then there’s environmental impact. Taking the animals out of the industry drastically reduces land and water use, and it can help reduce greenhouse gas emissions. Animal agriculture is responsible for about 15 percent of greenhouse gases, mostly from enteric methane burped up by ruminants like cattle and goats. No cows, no methane, and no need to cut down tropical forests for new ranches.

Will all those advantages pan out? The climate impact is particularly uncertain, since all the analyses have had to speculate about inputs and energy required in lab-grown meat.

Also, where will the growth medium come from? How much electricity will a full-scale factory need? None of the analyses (that I’ve seen) take into account the impact of having to find substitutes for animal byproducts. What will cats eat? What will shoes be made from?

We also don’t know if consumers will find all of this compelling. Asking whether we’ll see mainstream acceptance of a product that is completely unfamiliar, unavailable in the near term, and very hard to explain is a big ask.

According to Colleen McClellan, the director of client solutions at the consumer research company Datassential, only 10 percent of consumers are familiar with lab-grown meat, and they are disproportionately tech enthusiasts and young people. Among them, personal health and larger concerns about sustainability are about equally important, so the environmental footprint may indeed resonate.

How it will go down with everyone else is an open question. “We have no way of knowing how consumers will react to the prospect of lab-grown meat,” says Wurgaft.

The biggest determinant of success may have to do with a much more prosaic factor: money.

To gauge the long-term prospects of lab-grown meat, follow the money

Lab-grown meat is poised to disrupt a massive industry, and in some cases, the industry is even investing in the disruption. Tyson Foods and Cargill, two of the biggest meat processors in the country, have both put money into lab-grown meat startups. As Tyson CEO Tom Hayes said in a recent Bloomberg interview, “If we can grow the meat without the animal, why wouldn’t we?”

Meat the old-fashioned way is filled with distasteful necessities that consumers don’t want to know about. There’s a reason sausage-making is the idiom for unsavory processes. Concentrated animal feeding operations, or CAFOs, are a culmination of farmers’ history-long quest to grow animals more efficiently. But the bad PR that comes from both the farms and the slaughterhouses is something the industry would be happy to dispense with, if there were an alternative.

It could be a while, though, before most of us can taste the alternative for ourselves. Wurgaft believes the most reasonable claims suggest a product “that could be presented at restaurants as a stunt” is “relatively close,” and the industry could use those kinds of releases to string us along “maybe for another decade.” That would buy time for them to develop more viable products that could be scaled up.

The lab-grown chicken from Just will get a small, restaurant-based rollout. Similarly, Memphis Meats is working on lab-grown beef, poultry, and fish and expects to have a product on the market “in the near future,” sold at a “premium price” in “select locations.” Memphis Meats’ last public production cost estimate, from last year, was $2,400 per pound, and the company aims to get that below the production cost of conventional meat. So there’s clearly work to be done.

But people and money are on the job. And with a growing population with a growing appetite for meat, there’s a lot riding on it. Lab-grown meat won’t be what’s for dinner in the next few years, but humans are planning to eat meat for the foreseeable future. And in the long run, at least some of it is likely to come from a lab.

Tamar Haspel is a freelance food and science journalist. She writes the James Beard Award-winning Washington Post column Unearthed, and farms oysters off Cape Cod.