Tell us what you have; get the equivalent amount of every other type of yeast.
Recipe calls for fresh yeast but you have instant? Or active dry when the recipe wants rapid-rise? They’re interchangeable if you adjust the amount. As a guide, instant yeast is the most concentrated, active dry is a little less so, and fresh yeast — being mostly water — you need about three times as much by weight.
| From | To active dry | To instant | To fresh |
|---|---|---|---|
| Active dry | 1× | 0.8× | 2.5× |
| Instant | 1.25× | 1× | 3× |
| Fresh | 0.4× | 0.33× | 1× |
A packet of active dry (7 g / 2¼ tsp) is replaced by about 5.6 g (a scant 1¾ tsp) of instant yeast.
Use roughly 2.5 times the weight of active dry, or 3 times the weight of instant, when substituting fresh (cake) yeast.
No — instant (rapid-rise) yeast can be mixed straight into the dry ingredients. Active dry yeast is traditionally dissolved in warm liquid first.