Robert Moreland

“Yeast can travel on dust, and air currents carry yeast to new areas. The yeast settle on just about every surface, anxious to find more sugars to ferment so they can multiply. Look at that sunshine streaming in through the brewery window. Do you see the dust particles? There is a good chance they are carrying native yeast, and bacteria, too, just waiting for an opportunity to land in your beer.”
― Chris White, Yeast: The Practical Guide to Beer Fermentation