The three types at a glance
- Instant (rapid-rise / bread-machine) — fine granules, very active, mixes straight into the flour. The most convenient.
- Active dry — larger granules, traditionally dissolved in warm liquid first to “bloom”. The most common in older recipes.
- Fresh (cake / compressed) — a moist block sold refrigerated. Beloved by some bakers, but perishable and harder to find.
They’re all the same species of yeast — the difference is how they’re processed and how much live yeast you get per gram.
Conversion ratios
By weight, instant is the most concentrated, then active dry, then fresh.
| If the recipe calls for… | Instant | Active dry | Fresh |
|---|---|---|---|
| Instant | 1× | ~1.25× | ~3× |
| Active dry | ~0.8× | 1× | ~2.5× |
| Fresh | ~0.33× | ~0.4× | 1× |
In practice, most home bakers swap instant and active dry 1:1 by volume and adjust the method (see below). For precision — especially in enriched doughs — go by weight: 7 g (one packet / ¼ oz) of instant is about 2¼ teaspoons.
How to use each (the part people get wrong)
- Instant — add it straight to the dry ingredients. No need to dissolve it first.
- Active dry — bloom it in warm liquid (100–110°F / 38–43°C) with a pinch of sugar for 5–10 minutes until foamy. Modern active dry can be mixed in directly too, but blooming proves it’s alive.
- Fresh — crumble it into the warm liquid and stir to dissolve before mixing.
Blooming is also a test: if active dry or fresh yeast doesn’t foam in warm water, it’s dead — start over with fresh yeast rather than waste your flour.
Storage & shelf life
Dry yeasts (instant and active dry) keep for months in a cool, dry place — and far longer in the freezer, where many bakers store an opened jar. Fresh yeast lasts only a couple of weeks refrigerated, which is the main reason most home bakers prefer the dry forms.
Always check the date. Old yeast is the single most common reason a loaf fails to rise — see the troubleshooting in the pillar guide.