At Jardinière, an upmarket restaurant in San Francisco, the Impossible Burger is served in a pretzel bun with buttery lettuce, tomato relish, vegan mayonnaise, caramelised onions, avocado and Dijon mustard. Brown on the outside, the patty was pink in the middle. In the mouth, it felt juicy, fatty and acceptably bloody. Sandwiched in a bun and slathered in condiments, it could easily be mistaken for real meat.

Protein and dairy substitutes have been around for years. The difference with the Impossible Burger – created by Patrick Brown, a Stanford biochemist, and backed by Bill Gates – is the amount of research that has gone into mimicking meat. The task is complex. When meat is cooked, a series of molecular reactions between amino acids and sugars produce hundreds of flavour compounds. It is this process – called the Maillard reaction, after Louis-Camille Maillard, the French chemist who first described it – which gives browned meat its distinct taste and smell.

When cooked together, the wheat protein, potato protein and coconut oil that make up an Impossible Burger achieve the colour and texture of grilled meat. Emulsified coconut oil melts in a similar way to beef tallow, giving the patty a fatty sizzle; wheat protein, serving as the muscle tissue, adds chewy robustness; potato proteins, acting as connective fibres, become firm at high temperatures and lend the patty its freshly seared appearance. The inclusion of leghemoglobin, also known as heme protein, makes it “bleed”. Heme, an iron-containing compound, circulates in blood, but it is also found in plants. The scientists at Impossible Foods inject the soybean’s heme gene into yeast cells so their burger looks and tastes à point.

Brown’s burger has competitors. Beastly Sliders are beige rounds with prefabricated sear marks made by Beyond Meat, another company that has attracted investment from venture-capital firms. They are made from pea-protein isolate. Like the Impossible Burger, they contain coconut oil to mimic the fat that sizzles when seared. Their bloodiness is derived from beetroot.

The similarities only go so far. One review of Beastly Sliders likened their appearance to dog food. This was a fair assessment. But I would not be deterred, sautéeing them and serving them with onions, lettuce and tomatoes, alongside a glass of pea-based milk. In the pan they emitted a distinctly vegetal aroma, and they tasted similar to an ordinary veggie burger: nutty, almost tempeh-like – in other words, not at all meaty. The Maillard reaction didn’t happen. The milk, meanwhile, resembled liquid barium or the slurry-like food replacement Soylent.

New Wave Foods aims to create sustainable shrimp from red algae and pea protein. Nailing the appearance of shrimp proved relatively easy – red algae has a peachy flush when cooked. The algae also imparts a marine tang which is central to a shrimp’s taste, although the product is deep-fried which makes it easier to disguise shortcomings in flavour. Replicating the texture proved trickier. Water temperature and pH levels affect the texture of algae. “Shrimp is more challenging in some ways,” co-founder Dominique Barnes says. “We’re recreating almost the entire body, an animal body, as opposed to a fillet of a fish where you’re simply looking at a muscle.”

The ambitions of these companies are admirably ecological. Impossible Foods claims its burger is produced with 95% less land, 87% less greenhouse gas, and 74% less water than a regular beef burger. But consumers will continue to gnaw at real bones if the alternatives are more expensive. All these products are pricier to manufacture than a Peperami or a pint of milk, thwarting ambitions for mass-market dominance. In 2013, Mark Post, a vascular biologist at the University of Maastricht, created a cultured meat patty from thousands of strands of muscle tissue extracted from bovine stem cells. This turned out to be about as appetising as it sounds, and the high price was even more off-putting: producing one burger cost $330,000.

There are practical challenges to producing plant-based substitutes efficiently and bringing them to market. Barnes says that one of the biggest hurdles for New Wave Foods was finding a manufacturing facility that had laboratory-quality processing equipment. Impossible Foods currently supplies just a handful of American restaurants. New Wave Foods supplies popcorn shrimp to Google’s employee cafeteria, although a retail launch is planned for the next couple of years. We might be waiting a while for the cows to come home for good.