Which Yeast is Which?
There is a wide range of yeast available at BakeryBits. Which one should you choose, what's the difference, how should they be used? Some yeasts are general purpose while others are specifically formulated for a particular job - raising a high-sugar dough sugar as panettone for example. Many versions of yeast have arisen in response to commerical bakery plants that want to introduce yeast at a specific point in their processes. The result is that there is a wide variety of baking yeast available, despite all being of the same strain (Saccharomyces Cerevisiae), whether dried, fresh, organic or non-organic. Each variety has been prepared to suit preferred methods of working (fresh/dried), preferred food standards (organic/non-organic/gluten-free) and some specialised yeasts (osmotolerant and pizza yeast).
Dried active yeast, whether organic or non-organic is dormant, granulated live yeast waiting to be rehydrated so it can get to work in your dough. So to use it, you must get it wet first: simply add the required quantity to some lukewarm water before adding to the flour. Water that is too cold can cause the yeast to be shocked resulting in many cells being unable to reconstitute themselves, thereby becoming unviable. Fresh and dried active yeast works in the same way but some prefer one over the other remembering to use twice the weight of fresh to dry.
Fresh active yeast is the same as the dried, just not dried. It too should be added to water and dissolved before adding to the flour.
Some bakers like to add a little sugar to the warm water. It isn't necessary but will make the yeast reconstitute more quickly and, if there is any doubt over the viability of the yeast, it will froth and show activity before adding to the flour.
We have several variants of active yeast from the general purpose Saf-Levure Active Dried Yeast to the organic Bioreal range from Agrano which are available either in dried or fresh forms, and in various pack sizes and with an organic gluten-free dry active version (which can be used in exactly the same way as the standard). Both the Bioreal dried active yeast and the Bioreal fresh active yeast may be used in the same way but using twice the weight of fresh than dry.
Instant Dried Yeast
Instant dried yeast is designed to be added straight to the flour, to be as convenient as possible. It contains the same strain of yeast as active yeast but has had an emulsifier (E491 or sorbitan monostearate), added which protects the yeast while dry and helps rehydration. If you want to, this yeast can also be rehydrated prior to use but it is not necessary. This yeast’s particles are much smaller than the active dried yeast’s particles and this helps with dispersion through the dough.
There are several variants of instant dried yeast - the standard, general purpose Instant Yeast also known as Red Label for all breads, then the osmotolerant (high sugar) Saf Gold Instant Yeast yeast for enriched doughs, designed to rise vigorously in the presence of lots of sugar which otherwise impedes yeast and then there is a special Saf Pizza yeast specifically formulated to be used when making pizza dough. It has special properties that stop the dough shrinking back when stretched - very handy for pizzas.