Yeast Converter 🍞

Enter the amount of yeast you have, select the type, and see the equivalent in any other yeast type.

The Yeast Converter lets you swap between the three commercial bread yeasts — fresh (cake) yeast, active dry yeast, and instant (rapid-rise) yeast — without altering rise times or flavor. Each form contains a different concentration of live cells: fresh yeast is roughly 70% water and the most fragile, active dry yeast is dehydrated and needs proofing in warm liquid, instant yeast is fine-grain dehydrated and can be mixed straight into the flour. Recipes published in Europe almost always specify fresh yeast, US recipes default to active dry, and modern American bread books often specify instant. Using the wrong amount throws fermentation off by a factor of two and either ferments too fast (yeasty, alcoholic) or too slow (dense, under-risen). Enter the amount and type you have, and the converter returns the equivalent weight of the other two types plus the correct activation tips.

How to Use the Yeast Converter

  1. Select Source Yeast — Choose the yeast type your recipe calls for or that you have on hand: fresh, active dry, or instant.
  2. Enter Amount in Grams — Enter the weight in grams. If your recipe gives the yeast in teaspoons, weigh the teaspoon — 1 tsp instant yeast ≈ 3.1g.
  3. Read Equivalent Weights — The calculator shows the equivalent weight in the other two yeast forms. Use this number directly in your recipe.
  4. Activate Correctly — Fresh yeast: crumble into 35–38 °C (95–100 °F) lukewarm water. Active dry: proof in 38–43 °C (100–110 °F) water with a pinch of sugar for 10 minutes. Instant: mix straight into the flour.
  5. Adjust Liquid If Needed — Fresh yeast carries water — replacing 30g fresh with 10g instant removes roughly 21g of liquid from the formula. Add that water back to the dough liquid for high-precision recipes.

Formula Reference

Conversion ratios used: fresh × 0.4 = active dry; fresh × 0.33 = instant; active dry × 0.83 = instant; instant × 1.2 = active dry; active dry × 2.5 = fresh; instant × 3 = fresh. These ratios reflect the live-cell concentration in each form — fresh yeast is mostly water, active dry is roughly 92–94% solids after dehydration, instant is similar but with smaller particles for direct mixing. Liquid adjustment: fresh yeast contributes ≈70% of its weight as water. When swapping fresh for instant, add (fresh weight − instant weight) × 0.7 grams of extra liquid to the recipe.

Source: Lallemand Inc. — Yeast Conversion Reference; SAF Lesaffre Baker's Yeast Technical Sheet; Peter Reinhart, The Bread Baker's Apprentice (Ten Speed Press, 2001).

FAQ

How much instant yeast equals 1 packet of active dry?

A standard 7g (¼ oz) packet of active dry yeast is equivalent to about 5.8g of instant yeast — roughly 1¾ teaspoons. Most home bakers use 6g or 2 teaspoons interchangeably.

Do I have to proof instant yeast?

No. Instant yeast (also called rapid-rise or bread machine yeast) is designed to be mixed directly into the dry ingredients. Proofing is only needed for active dry yeast and fresh yeast.

Can I substitute sourdough starter for commercial yeast?

Yes, but it changes the recipe. Use 100g of 100% hydration starter to replace about 1g of instant yeast, and reduce the recipe's flour by 50g and water by 50g to compensate. Fermentation will take 2–3× longer and develop more flavor.

Why does my yeast not foam during proofing?

Either the water is too hot (above 46 °C / 115 °F kills yeast), too cold (below 27 °C / 80 °F is sluggish), or the yeast has expired. Proofed yeast should produce a creamy foam in 5–10 minutes.

How long does each yeast type keep?

Fresh yeast: 2 weeks refrigerated. Active dry: 1 year unopened, 4 months opened in the fridge. Instant: 2 years unopened in the freezer, 4 months opened in the fridge. Always check the expiry date and proof a small amount if unsure.

Related Tools