What is a decoction mash?

A decoction mash involves removing a portion of the mash, boiling it, then returning it to raise the temperature of the remaining mash. This traditional German technique develops melanoidins and rich malt flavours.

Should I pull thick or thin decoctions?

Pull thick decoctions (mostly grain with some liquid) for more malt flavour development. Thin decoctions (mostly liquid) are less impactful on flavour. Traditional single decoctions are thick.

Is decoction necessary?

With modern well-modified malts, decoction is not strictly necessary. However, it can add complexity to German and Czech-style lagers. Many award-winning Pilsners and Märzens use decoction mashing.

Is a single, double, or triple decoction best?

Single decoction is most practical for homebrewers and adds noticeable malt complexity. Double decoction gives richer melanoidin character, ideal for Märzen and Bock. Triple decoction is traditional for Czech Pilsner but time-consuming. Most homebrewers find single decoction sufficient.

Can I simulate decoction with melanoidin malt?

Adding 3-5% melanoidin malt to a single-infusion mash approximates some of the malt richness from decoction. It is not identical — decoction also affects protein and enzyme behaviour — but it is a practical shortcut that produces similar flavour results.

BrewCalcs

Decoction Calculator

Calculate decoction volume needed to raise mash temperature.

Total Mash Volume

Current Mash Temperature

Target Temperature

How We Calculate This

Decoction Formula

Decoction Volume = Mash Volume x (Target Temp - Current Temp) / (100 - Current Temp)

This assumes the decoction is boiled to 100°C before returning to the main mash. The formula calculates what fraction of the mash to pull and boil.

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.