I recently began baking bread. I've had great success with recipes where the yeast is bloomed in liquid. This is easy because you can see when the yeast is activated. A lot of recipes call for the yeast to be added to the dry ingredients and warmer liquids. These recipes scare me. How do you know that the yeast is doing yeasty stuff? How else is the process different with the yeast in dry ingredients?
Dissolving yeast in lukewarm water was the standard until three or four years ago. Old manufacturing techniques produced a much larger yeast granule that required dissolving before use. Many mistook that process for proving the yeast. While you can see the yeast activity, the real purpose of mixing dry yeast in water was to dissolve it.
Since recent improvements in manufacturing techniques produces a much smaller yeast granule, yeast no longer needs to be dissolved before use. Interestingly, instructions on packaging still directs bakers to dissolve the yeast. Instant yeast was actually developed to be added directly to dry ingredients.
But you can certainly prove ("prove" is not a typo) the yeast if you are concerned about its viability. Simply use 60g (2 oz; 1/4 cup) of the liquid to prove the yeast. If there is no liquid in the recipe, prove the yeast in 60g water, then add a bit more flour to the recipe. Active dry yeast (ADY) is slower to activate, so you will need to give ADY more time to prove.
Since yeast is a living organism it's important to use yeast not more than 6 months old. After opening, store yeast in an airtight container either in the refrigerator or the freezer. Yeast should be used within four months if stored in the refrigerator; six months if stored in the freezer. Since I purchase yeast in one pound sacks, I frequently have more yeast than I will use in 6 months. I have used yeast that has been stored as long as nine months without any noticeable loss of activity.
ADY and instant/ rapid rise yeast can be used interchangeably. However ADY takes longer to work. Also, for a long rise, refrigerated dough, or if you intend to freeze the finished dough, do NOT use instant/rapid rise yeast. Instant/rapid rise yeast is a different strain of yeast and a much smaller granule size. So instant/rapid rise yeast activates about 50% faster than ADY. If you use instant/rapid rise yeast in a long ferment, the dough will be over-proofed.
There is also a flavor difference given the different strains of yeast. ADY is much more mild. Instant/rapid rise yeast can give off that "yeasty" flavor and scent.
The type of yeast does matter when making a sweet dough. While yeast feeds on sugar, too much sugar will in fact inhibit yeast development. As a living organism, yeast requires water to reproduce. Sugar is hygroscopic, so it directly competes with the yeast for water in the dough. If there is more than 60g (2 oz; 1/4 cup) sugar per 140g (5 oz; 1 cup) of flour, the sugar will inhibit yeast development by robbing the yeast of water. That's why sweet doughs take forever to rise.
SAF Gold yeast is a strain that requires less water to reproduce. So SAF Gold is the best yeast to use in sweet dough. Do not use SAF in low sugar doughs.
If you don't bake a lot of sweet doughs, Red Star Quick-Rise is a good yeast to stock as it works well in both low sugar and sweet doughs.
SAF and Red Star are the same company. It's the more common brand used in commercial bakeries. Red Star makes a yeast called Platinum. Platinum is instant yeast mixed with dough enhancers. The enchanters creates a dough which is much more forgiving and creates incredible rise. So the home baker can achieve that bakery quality rise.
