Impossible Foods, makers of the super popular “bleeding” plant-based burger, has been on a hot streak lately. In January they launched a (very tasty) version 2.0 of their iconic “meat,” which is now available in four countries. They’re on the menus of major fast-casual and fast-food chains like Red Robin, Qdoba, White Castle, and, soon, Burger King. And later this year, they’ll hit grocery shelves.

But it’s not all smooth sailing. Eater reported yesterday that Impossible is having trouble making enough product to keep all their restaurant partners stocked.

The news is not exactly surprising. As we’ve noted time and again, consumers can’t get enough plant-based protein. This news from Eater shows that demand for meat alternatives seems to be outpacing the production capabilities of at least some popular vegan meat companies.

Impossible isn’t the only one grappling with the supply-and-demand problem. Beyond Meat, one of their main competitors, went through similar growing pains last year when fans complained that Beyond’s plant-based burger patties were often sold out at grocery stores. The El Segundo-based startup even had to delay its scheduled entry into the U.K. due to difficulty meeting demand.

Since then Beyond Meat has opened up a second production facility and seems to have bounced back. I haven’t heard any other internet murmurings of “out of stock” signs (comment if you have!), and the aforementioned Eater piece notes that many New York restaurants who couldn’t get their Impossible burgers are replacing them with Beyond. In fact, Beyond’s shortages seem to be behind them as the company prepares to go public later this week.

Even bigger alternative meat companies are having to add new production means. Maple Leaf Foods, which owns Field Roast and Lightlife Foods, recently announced plans to build a $310 million plant-based protein factory — the largest one in the U.S. As demand for meat alternatives continues to grow I’m betting we’ll see even larger alt-protein factories being built, especially once poultry giant Tyson fulfills its promise to enter the plant-based meat space.

In the end, this shortage isn’t a devastating blow for Impossible. It is a reality check, both to consumers and the company, that the startup darling isn’t hiccup-proof. The shortage also shows that the skyrocketing demand for plant-based protein isn’t going to slow down anytime soon.

Impossible is clearly aware of their production issues and scrambling to fix them. Eater notes that the startup is increasing staff and hours of operation at its plant in Oakland, California, and that it plans to double production by the summer.

That’s a good start. However, Impossible is planning to roll out to 7,000-plus Burger King locations soon, doubling its restaurant footprint. It’s also going to launch in retail sometime this year. With all these moves, Impossible may have to start thinking beyond (ha) just adding another production line if it plans to continue expanding at such a rapid clip.

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