“The big thing for me was not thinking of a recipe as just the ingredients but also the dilution, aeration and temperature,” said Mr. Peterson, who went to culinary school and has degrees in physics and engineering. “That’s the big difference between drinks at a bar and drinks at home.”

The idea for a take-home cocktail cube had percolated when Castalia first opened, but the couple were so focused on getting people in the bar that they didn’t have time for extraneous products. Now they are making — and selling out of — 750 cubes every weekend. They would do more, but they are limited to the space in their home freezer.

“I take solace in doing stuff,” Mr. Peterson said.

Experiment with what you know.

Some businesses find themselves in a position to help fight the pandemic. Distilleries like Cathead Distillery in Jackson, Miss., are converting production to hand sanitizer, while apparel companies, like Simms Fishing Products in Bozeman, Mont., are making hospital gowns. Still others are making masks.

But all that product has to find its way to hospitals and homeless shelters. That’s where Garry Cooper comes in. His Chicago technology firm, Rheaply, specializes in connecting resources to the people who need them to reduce waste and overbuying.

He normally works with universities, government agencies and the world’s largest companies to help them better manage their inventories. When the pandemic broke out, he realized that there was no single place to go to find out who needed what — and who had it.