For me, there are only 2 kinds as far as the results I've seen - Live and dead. Live is good. Dead not so much.
Actually I have used 2 kinds - instant or quick yeast, aimed at the inflexible time frame of the bread machine; and active, which is what I use for pretty much everything including bread machine recipes. I don't use the packets because many of the breads I've made don't call for using that much yeast. Each packet is 2Ĺ teaspoons, and recipes like my ciabatta only call for 1Ĺ teaspoons for 3 loaves. What do I do with the leftover teaspoon? With the jar, I just measure out what I need.
Regular active yeast work seems fine without proofing it, but I usually do that anyway for insurance. It only takes 5 to 10 minutes to proof your yeast in a cup or less of warm (about 110įF) water. You can feed the yeast by adding 1/2 tsp of sugar to it if you like - that won't change the taste or texture of your bread - but it seems to be about the same whether I add sugar or not. The yeast and water still get sort of creamy looking and that tells me that the yeast is doing okay.
I keep my jar of Red Star in the freezer to help it last longer. I've had a jar for as long as 1Ĺ years still going strong. Using water that is too hot, or too much salt before the rise, can kill your yeast too.