Yeast Converter - Convert Between Yeast Types
Convert between active dry yeast, instant yeast, fresh yeast, and packets. Essential for bread baking and adapting recipes with different yeast types.
Reviewed by the Calcura editorial team · Last reviewed
- Question
- How do I substitute one type of yeast for another?
- Answer
- 1 US packet of yeast = 7 g = 2¼ teaspoons active dry yeast = 2 teaspoons instant yeast = 17 g (0.6 oz) fresh (cake) yeast. To swap: instant = active dry × 0.75 (instant is more potent); fresh = active dry × 2.4 by weight. Active dry needs to be proofed in warm water first; instant can go straight into the dry ingredients.
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- Formula
1 packet = 7 g = 2¼ tsp active dry = 2 tsp instant = 17 g fresh- Caveats
- Fresh yeast is perishable — about 2 weeks refrigerated; active dry and instant keep for months.
- Substitute by weight, not volume, when possible — density varies between brands.
- Doubling yeast to speed rise makes bread taste yeasty. Better to let time do the work.
Yeast Conversion Table
Industry-standard equivalents from Red Star / Fleischmann's / SAF.
| Active Dry | Instant (Rapid-Rise) | Fresh (Cake) | Packets |
|---|---|---|---|
| ¾ tsp (2.3 g) | ½ tsp (1.8 g) | 5 g | ⅓ packet |
| 1½ tsp (4.7 g) | 1 tsp (3.5 g) | 11 g | ⅔ packet |
| 2¼ tsp (7 g) | 2 tsp (6 g) | 17 g (0.6 oz) | 1 packet |
| 4½ tsp (14 g) | 4 tsp (12 g) | 34 g | 2 packets |
| 6¾ tsp (21 g) | 6 tsp (18 g) | 51 g | 3 packets |
| 9 tsp (28 g) | 8 tsp (24 g) | 68 g | 4 packets |
What This Calculator Does
Converts between the four commercial forms of baker's yeast — active dry, instant (rapid-rise), fresh (cake), and standard packets — so a recipe written for one can be made with another. Packet size and ratios follow the Red Star/Fleischmann's/SAF industry standard: 1 packet = 7 g = 2¼ tsp active dry = 2 tsp instant = 0.6 oz (17 g) fresh.
When To Use This Calculator
Recipe calls for fresh yeast but you only have instant
Recipe asks for 1 oz fresh yeast → converter returns 3.33 tsp instant. Mix directly into flour.
Converting a packet count to teaspoons for a scale-based recipe
3 packets active dry = 6.75 tsp = ~21 g. Useful when scaling up bread batches.
Substituting active dry for instant in a no-proof recipe
Recipe calls for 2 tsp instant → 2.24 tsp active dry. Bloom it in 110 °F water for 10 min first to activate.
Using bulk yeast from a jar instead of packets
Recipe needs 1 packet instant → measure 2 tsp from the jar.
How It Works
All commercial baker's yeast is the same organism (Saccharomyces cerevisiae), but the forms differ in moisture and how densely packed they are. Active dry yeast is ~5% moisture with larger granules requiring rehydration; instant (also called rapid-rise or bread-machine yeast) is ~5% moisture in smaller granules that rehydrate in dough; fresh (cake) yeast is ~70% moisture pressed into blocks. Because the dry forms contain more live cells per gram, you need less of them. The ratios here come from manufacturer guidance: instant is ~11% more potent than active dry per teaspoon; fresh yeast needs roughly 2.5–3× the weight of instant. Packet size (7 g / ¼ oz) is a Fleischmann's standard adopted across the US industry.
Formula
instant_tsp ≈ active_dry_tsp × 0.89 | fresh_oz ≈ instant_tsp × 0.30 | packet = 2.25 tsp active dry = 2 tsp instant = 0.6 oz freshReal-World Example
Scenario
A European sourdough-enriched brioche recipe calls for 25 g fresh yeast. You have a jar of SAF instant yeast and a kitchen scale.
Calculation
25 g fresh ≈ 0.88 oz. From the chart: 1 oz fresh = 3.33 tsp instant. So 0.88 oz × 3.33 = 2.94 tsp ≈ 3 tsp instant (about 9 g). Since instant doesn't need proofing, mix it straight into the dry ingredients.
Result
Substitute ~9 g (3 tsp) SAF instant for the 25 g fresh yeast — about 36% of the weight — and skip the blooming step.
Common Mistakes to Avoid
Mistake: Using equal volumes when swapping dry for fresh
Solution: Fresh yeast has ~14× more water per teaspoon. Use 1/3 to 1/4 the volume — this converter returns the correct weight ratio.
Mistake: Proofing instant yeast in hot water anyway
Solution: Water at 110 °F is fine for active dry but too cool for optimal instant performance. Either use active dry for proofing or skip the proof when using instant and rely on the dough itself.
Mistake: Killing yeast with water that is too hot
Solution: Yeast dies above ~130 °F. Use 100–110 °F for active dry blooming; dry ingredients reach yeast-friendly temps on their own once mixed.
Mistake: Assuming RapidRise, Quick-Rise, and bread-machine yeasts are all identical to instant
Solution: They're all instant-type yeasts but some are cut finer. Substitute 1:1 for instant, and for slow-ferment doughs (overnight), reduce by ~25% to avoid over-proofing.
Related cooking tools
When This Isn't the Right Tool
Sourdough starter / wild yeast cultures
Use instead: Commercial-yeast ratios don't apply to natural leavens, which depend on culture vitality and bacterial balance. Use a baker's-percentage levain formula instead.
Brewer's or nutritional yeast
Use instead: Those aren't leavening agents. Brewer's yeast ferments sugars in brewing; nutritional yeast is inactive. They can't substitute for baking yeast.
Dough-conditioned or pre-fermented recipes (poolish, biga, sponge)
Use instead: Yeast is split between the preferment and the final dough. Convert each stage separately, keeping the preferment time unchanged.
How to Verify This Calculation
Quick checks: 1 packet should always return exactly 2.25 tsp active dry, 2 tsp instant, and 0.6 oz fresh. 1 tsp active dry should be about 0.89 tsp instant. If the tool deviates, the conversion table was modified.
Sources
- Fleischmann's Yeast — product guide and conversions — Manufacturer source for the 7 g packet standard and active-dry/instant ratios.
- Red Star Yeast — dry-to-fresh conversions — Primary source for fresh-to-dry yeast weight equivalences.
- King Arthur Baking — yeast types and substitutions — Test-kitchen guidance on when active dry and instant can be swapped 1:1.
- USDA FoodData Central — yeast composition — Authoritative moisture content (%) references for dry vs fresh yeast.
Reviewed by the Calcura editorial team · Last reviewed