Yeast Starter Calculator

Calculate the DME and water needed for a yeast starter to grow enough cells for your batch. Supports stirred and unstirred starters with growth rate modeling.

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How It Works

A yeast starter propagates yeast cells by providing a small amount of wort for them to consume and reproduce. The ideal starter gravity is 1.036-1.040 — higher gravities stress the yeast without improving growth. A stir plate dramatically improves growth (2-4x) by keeping yeast in suspension and providing constant oxygenation. The basic recipe is about 100 grams of DME per liter of water. Allow 24-48 hours for the starter to complete. Cold-crashing the finished starter lets you decant the spent beer and pitch only the yeast slurry, avoiding off-flavors from the starter wort. Step starters (multiple stages) can achieve even higher cell counts for very high-gravity beers.