The art of baking at home, while not exactly lost, has been on a decline as Americans slowly shifted from eating in to dining out. But with over 90% of the U.S. now under some form of stay-at-home order, it appears that an increasing number are dusting off old recipes for breads, pastries, cookies and cakes.

As a result, baking staples can be hard to find, as society finds comfort in carbohydrates. Sales of baking yeast were up 457% over last year for the week ending March 28, according to Nielsen data. Flour was up 155%, baking powder up 178%, butter up 73% and eggs up 48%.

Kelly Olson, a spokeswoman for Red Star Yeast, said the demand spike was unexpected and it’s doing all it can to replenish empty store shelves. “We hope to have availability at retailers back to normal within a few weeks,” Olson said.

It has also been chaos for flour makers. Central Milling and Bob’s Red Mill have posted notes to customers describing an unprecedented surge in demand.

Hopkinsville Milling Co. is packing twice as much flour as normal, according to company President Robert Harper. This is usually a slow time of year for the mill, which sells mostly self-rising wheat-based flour and corn meal.

Home baking tends to slack off as winter turns to spring, but about three weeks ago, the orders started pouring in. “It started to look like Thanksgiving and Christmas all rolled into one,” Harper said. “People have time on their hands and are trying to save some money.”

While the Great Depression turned the Great Generation into frugal home bakers, Baby Boomers turned away from cooking and toward working outside the home, said Sharon Davis, a director at the Home Baking Association, a consortium of farms and commodity groups.

Home baking began dropping off in the 1960s, and today, with many households having two working parents, there’s less time for basic meal preparation, never mind baking. Still, a rising U.S. population contributed to consumption gains for wheat-based flour in recent years, even as per-capita use dropped from 146 pounds in 2000 to 132 pounds in 2018, federal data show.

While restocking of grocery shelves isn’t happening as fast as consumers are buying, there’s no actual shortage.

“Here in the U.S., our wheat supplies would be considered abundant at this point,” said Erica Olson, market development and research manager at the North Dakota Wheat Commission.

Today’s bare shelves are a logistics problem, not a supply issue. “People were rushing to buy flour they may or may not use, and the mills were not prepared for that,” Olson said. The disconnect between what is produced in American fields and what ends up in the baking aisle is a temporary blip, she said.

It’s a similar story outside the U.S. Alex Waugh, director general of the National Association of British & Irish Millers, said British millers have been working around the clock, “genuinely milling flour 24-hours-a-day-seven-days-a-week to double the production of retail flour in an effort to meet demand.”