Crosby's Kitchen & CocktailInceptus

As it happened, Joran walked into the brewery that day with an ear-to-ear grin. The crisp, frigid air, he announced, was clean and healthy. In sum, perfect conditions for open fermentation, a process by which wild yeast is “caught” from the air instead of cultivated. So the brewers transferred wort into a mini-fermenter and placed it outside, exposed to the air. Over the next few days they observed the signs of spontaneous fermentation and were rewarded with a wild yeast strain that literally arrived with the wind.