Quantities of the different yeasts:
1 x 7gm sachet of Instant dried yeast would be equivalent to : 15 gm fresh yeast 10 gm active dried yeast
Fresh yeast is the type most used by pro bakers. It must be refrigerated
Instant dried yeast was a new strain developed by yeast manufacturers, quicker to feed and generate gas. It includes an E-number that is an emulsifier, and works well whether it is tumbled through the dry flour (as manufacturer recommends) or thoroughly whisked in the dough liquor.
Active dried yeast was developed in yeast factories at roughly the same time as fresh yeast (middle of 19th century), and has absolutely no additives, hence is approved by the Real Bread Campaign. It is recommended to whisk it into the dough liquor, but not necessary to feed it sugar as often recommended.
Well, Panarians, thanks again for your contributions to the survey, and I hope you are generally pleased with my responses.
Good baking, Paul