How the Climate Is Affecting Your Optimal Mash Temps

Imagine early spring in the barley fields, and the ground has just thawed. The farmers are sowing the barley, burying their hopes and worries with the seeds.

In two weeks, shoots will push above the soil, seeking sunlight. A few weeks later, the stalks will be longer, with the head beginning to form. Pollination follows, and about two months after the first shoots find the light, the barley kernels start their development. Called “grain fill,” that phase lasts about a month, and it’s when the farmers are perhaps most concerned with the field conditions and weather report.

If the climate cooperates, the kernels will be plump with starch, and have restrained protein levels—a harvest that would bring a good price per bushel. However, wacky weather patterns during this critical period don’t stress only the farmer—they also stress the barley. Hot, dry conditions lead to higher protein levels and denser endosperms—changes that affect the work of maltster and brewer alike.

“Brewers have to change mashing conditions, or they will see challenges downstream,” says Glen Fox, a brewing scientist at University of California, Davis.