Case 1
- How much fresh yeast?
- 30g
10.00g
Open with these valuesFresh Yeast to Dry Yeast Converter
10.00g
Result: 10.00 gDivide the fresh yeast by three and you have the instant dry yeast: 21 g of fresh yeast is 7 g of dry, which is exactly one standard sachet. Fresh yeast is mostly water, so the dried form does the same work at a third of the weight. Brands vary a little, so treat the result as a starting point.
The numbers at a glance
| How much fresh yeast? (g) | Result (g) |
|---|---|
| 10.0 | 3.33 |
| 20.0 | 6.67 |
| 30.0Your value | 10.00 |
| 40.0 | 13.33 |
| 50.0 | 16.67 |
| 60.0 | 20.00 |
Worked examples
Case 2
- How much fresh yeast?
- 42g
14.00g
Open with these valuesCase 3
- How much fresh yeast?
- 21g
7.00g
Open with these valuesHow it's calculated
instant yeast = fresh yeast ÷ 3
- StepRead the fresh-yeast weight off the recipe — a standard cube is 42 g.
- StepDivide it by three to get the instant dry yeast.
- ResultStir instant yeast straight into the flour; no soaking needed.
What this number means
Three is the factor sources agree on
Fresh yeast divided by three gives instant dry yeast. The active-dry factor is disputed and quoted anywhere from fresh ÷ 2 to fresh ÷ 2.5.
The numbers line up with the packet
21 g of fresh yeast is exactly 7 g, one standard sachet, and a whole 42 g cube gives 14 g. The calculator also runs backwards when the recipe names the dry yeast.
Instant and active dry are handled differently
Instant yeast is stirred straight into the flour, while active dry is usually woken in warm liquid first. The conversion says how much to use, not whether the yeast still works.
A starting point, not a measured constant
Yeast is a live product and its lifting power varies between brand and batch. The divisors are rounded baking conventions.
Commonly misread
I can swap the two weights one for one.
Fresh yeast is largely water, so a third of the weight does the same work. 30 g of fresh yeast becomes 10 g of instant dry yeast.
Dry yeast always has to be dissolved in warm water first.
Instant yeast normally goes straight into the dry ingredients. Active dry is worth waking in warm liquid, and an old packet is worth proofing until it foams.
The 2.5 factor for active dry is as solid as the 3.
Sources disagree on the active-dry factor, quoting fresh ÷ 2 or fresh ÷ 2.5. This calculator uses the instant factor of three, which sources agree on.
Reference table
| Fresh yeast | In cubes | Instant dry yeast |
|---|---|---|
| 7 | A sixth of a cube | 2.33 |
| 21 | Half a cube | 7.00 |
| 30 | Two thirds of a cube | 10.00 |
| 42 | One whole cube | 14.00 |
| 100 | Small bakery batch | 33.33 |
Questions
How do I convert fresh yeast to dry yeast?
Divide the fresh-yeast weight by three. 30 g of fresh yeast becomes 10 g of instant dry yeast, and 21 g becomes exactly one 7 g sachet.
Why do I need less dry yeast than fresh yeast?
Fresh yeast is largely water, while the dried forms have had that moisture driven off. The live yeast is therefore far more concentrated, and a third of the weight delivers the same rise.
What is the difference between active dry and instant yeast?
Both are dried, but instant yeast has finer granules and can be stirred straight into the flour, while active dry is usually woken in warm liquid first. Their conversion factors differ too, and sources disagree on the active-dry one — it is quoted anywhere from fresh ÷ 2 to fresh ÷ 2.5. This calculator uses the instant factor of three, which sources agree on.
Do I need to proof the converted yeast?
Instant yeast normally goes straight into the dry ingredients. Active dry is worth dissolving in a little warm liquid for a few minutes first, to see it foam and confirm it is alive. The conversion says how much to use, not whether the yeast still works.
How much fresh yeast is one sachet?
A 7 g sachet of instant yeast stands in for 21 g of fresh yeast, which is half a standard 42 g cube. Enter 21 above and the calculator returns exactly that.
Sources and last check
Information, not professional advice.