How much dry yeast equals a cube of fresh yeast?

One 42 g cube of fresh yeast equals about 14 g of dry yeast (two 7 g packets) - dry yeast is roughly one third of fresh by weight, and each leavens about 500 g of flour.

What types of yeast are there?

Fresh (cake) yeast, active dry yeast and instant (fast-acting) dry yeast. Instant can be mixed straight into the flour; active dry is usually proofed in warm water first. Sourdough is a wild-yeast alternative that needs no commercial yeast at all.

Can I replace yeast with sourdough?

Yes. As a rule of thumb, leaven with about 20% of the flour weight as active sourdough starter and expect a longer proof (4 to 12 hours instead of 1 to 2). It trades speed for flavour, keeping quality and digestibility.

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Yeast Converter: fresh ↔ dry

Convert fresh yeast to dry (and back), see how many cubes or packets you need, how much flour it leavens - and how to swap it for sourdough.

Fresh yeast (g)

14 gDry yeast

1Fresh cubes (42 g)

2Dry packets (7 g)

~500 gLeavens flour

Rule of thumb: dry yeast is about ⅓ of fresh by weight, and ~42 g fresh (or 7 g dry) raises ~500 g of flour.

Skip the yeast entirely?

To leaven ~500 g of flour with sourdough instead, use about 100 g of active starter and a longer proof (4–12 h). No commercial yeast needed.

Types of yeast (Hefearten)

Fresh (cake) yeast is the moist block sold in the fridge - 1 cube is 42 g. Active dry yeast is dehydrated and usually proofed in warm water first. Instant (fast-acting) dry yeast is finer and can go straight into the flour. All three are the same organism (Saccharomyces cerevisiae); they differ in moisture and speed, which is why the fresh-to-dry ratio above is roughly 3:1.

Sourdough vs yeast

Commercial yeast is fast: one organism, a quick, neutral rise in 1–2 hours. Sourdough is a living culture of wild yeast and lactic-acid bacteria - slower (4–12 hours), but it brings tangy flavour, a longer-keeping loaf and easier digestibility. You can leaven the same bread either way; sourdough trades speed for depth, and needs no packets at all. The catch is keeping a starter alive - which is exactly what a feeding rhythm (and a tracker) is for.