How much fresh yeast should I use if I want to use it instead of dry yeast?
Look at: http://whatscookingamerica.net/Bread/yeastbreadtip.htm


  Conversion Measurements for Using Different Yeasts in Recipes:

Multiply the amount of instant yeast by 3 for the equivalent amount of fresh yeast.

Multiply the amount of active dry yeast by 2.5 for the equivalent amount of fresh yeast.

Multiply the amount of instant yeast by 1.25 for the equivalent of active dry yeast.