Baking Basics: Dry Yeast vs Live Yeast
Ah, yeast. I get lots of questions about yeast. In Germany, you can buy dry yeast, which is the most common, and live yeast, which must be kept in the refrigerator. But what's the difference between them? And can you convert from one to the other? Let's talk about it. So, first off, what is yeast at all? As opposed to baking powder or baking soda, which both have chemical reactions that creates carbon dioxide that cause leavening, yeast is actually a living organism. Yeast is a fungus. When you buy live yeast, the yeast is cooled between 0° and 10°C, so refrigerator temperatures, and it becomes semi-dormant and stops growing. It will come out of its dormant state when warmed up and given something to feed on. It is fastest to get the yeast to grow by giving it sugar, but you can also use flour dissolved in water. What about dry yeast? The same concept, except instead of forcing dormancy by chilling the yeast, dry yeast has been forced into dormancy by dehydrating it. T...