A step mash rests at multiple temperatures to activate different enzymes. Common steps: protein rest (50-55°C), beta-amylase rest (62-65°C), alpha-amylase rest (68-72°C), and mash-out (76-78°C). Each step requires adding hot water to raise the temperature.

When should I use a step mash?

Step mashing benefits under-modified malts, wheat beers (protein rest), and recipes where you want precise control over fermentability. Most modern well-modified malts work fine with a single infusion.

Can my mash tun hold the extra water?

Each infusion step adds volume. Make sure your mash tun can hold the initial mash water plus all infusion additions. For large grain bills with multiple steps, you may need a larger vessel.

When is a step mash necessary?

Step mashing benefits undermodified malts, high-protein grains like wheat (for protein rest), and beers where you want precise control over fermentability. With modern well-modified malts, a single infusion at 65-68°C works for most recipes.

What are the common mash rest temperatures?

Acid rest: 35-45°C (pH reduction). Protein rest: 50-55°C (protein breakdown, head retention). Beta-amylase rest: 62-65°C (fermentable sugars). Alpha-amylase rest: 68-72°C (dextrins, body). Mash-out: 76-78°C (stop enzyme activity).

BrewCalcs

Step Mash Calculator — Infusion Steps

Calculate infusion volumes for multi-step mash schedules.

Current Mash Water Volume

Grain Weight

Current Mash Temp

Target Temp

Infusion Water Temp

Usually boiling (100°C)

How We Calculate This

Infusion Step Formula

Infusion Volume = Effective Mash Mass x (Target - Current) / (Infusion Temp - Target)

Effective mash mass includes water volume plus grain thermal mass (grain weight x 0.2). Run this calculator for each step in your mash schedule.

Frequently Asked Questions

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Last updated: 2025-02-20

All calculations are estimates. Always verify values and adjust based on your equipment and ingredients.