What temperature should I cold crash at?

Most brewers cold crash at 0-4°C. Lower temperatures promote faster yeast and protein flocculation. Aim for 0-2°C if your equipment allows, but anything below 5°C will help significantly with clarity.

How long should I cold crash?

A minimum of 24 hours gives noticeable improvement. 48-72 hours is ideal for most beers. Very hazy or high-protein beers may benefit from up to 5 days. Longer crashes rarely provide additional benefit.

Will cold crashing affect carbonation?

If cold crashing before bottle conditioning, enough yeast remains in suspension to carbonate. However, cold crashing will reduce the yeast count, so allow extra conditioning time (add 1-2 weeks). For kegged beer, this is not a concern.

Can cold crashing cause suck-back?

Yes. As beer cools, CO2 contracts and can pull sanitiser from your airlock into the beer. Use a balloon, a filled airlock with vodka, or a closed transfer setup. Some brewers attach a CO2 source at low pressure to prevent oxidation.

Should I cold crash lagers?

Absolutely. Lagers benefit enormously from cold crashing and extended cold conditioning (lagering). After fermentation and diacetyl rest, crash to 0-2°C and lager for 4-8 weeks for the cleanest results.

BrewCalcs

Cold Crash Calculator

Calculate cold crash timing and temperature for clear beer.

Current Beer Temperature

Target Crash Temperature

Batch Size

Cooling Method

How We Calculate This

Cooling Time Calculation

Cooling time is estimated from the temperature drop needed divided by the cooling rate: Hours = (Current Temp - Target Temp) / Cooling Rate. A standard fridge cools at roughly 2-3°C per hour, glycol systems at ~5°C/hr, and ambient cooling in a garage at ~0.5°C/hr.

Crash Duration

The recommended crash time at target temperature is 2-3 days for standard batches. Larger batches and lower target temperatures benefit from longer crashes. Total time includes both the cooldown period and the hold time at target temperature.

Frequently Asked Questions

Related Calculators

Fermentation Time Calculator

Estimate primary and secondary fermentation duration for your beer.

Diacetyl Rest Calculator

Calculate timing and temperature for a diacetyl rest in lagers.

Secondary Fermentation Calculator

Determine if and when to transfer to secondary fermentation.

Bottle Bomb Calculator

Check if your beer is safe to bottle based on gravity readings.

Lag Time Calculator

Estimate yeast lag time based on pitch rate, temperature and viability.

Last updated: 2025-02-20

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