His company makes a vegetarian turkey substitute called Tofurky. Tofurky is made from tofu. Tofu is made with soybeans. So what does Mr. Tibbott think of the idea of a hamburger made in a lab?

SETH TIBBOTT: "I think it sounds still pretty disgusting."

His company estimates that about three percent of Americans are vegetarian. Vegetarians do not necessarily want food that tastes like meat. But Seth Tibbott says a lot of other people might try meatless alternatives if those products did look and taste more like real meat.

SETH TIBBOTT: "In the industry, they're called flexi-tarians or they're called 'sometimes vegetarians.' And, depending on what study you look at, they're thirty to forty percent of America."

Turtle Island Foods is building a new Tofurky factory. It will let the company make three times as much Tofurky starting next year.

Biochemistry professor Patrick Brown at Stanford University in California has started his own company developing a meat substitute. His food scientists are working with plant proteins and oils to try to reproduce the look and taste of the real thing. But he says whatever they produce will also need a price that appeals to meat lovers.

PATRICK BROWN: "What we're intending to do is basically produce stuff that will compete by being substantially cheaper and every bit as good and essentially indistinguishable to a consumer who loves meat or dairy. That’s the only way I think you’re really going to win in the market."