Free Fermentation Temperature Controller Calculator
Calculate peak yeast metabolic heat, ambient thermal ingress, glycol chiller BTU/hr sizing, and heating pad wattage for beer, cider, and wine.
🍺 Fermenter & Batch Parameters
📊 Thermal Load & Equipment Sizing
Recommended Tools & Equipment
Tested hardware and components for high reliability
Frequently Asked Questions
How much heat does yeast produce during peak fermentation?
At peak krausen, active yeast produces between 1.5 and 2.5 BTU per hour per gallon of fermenting wort for standard ales (10–14°P / 1.040–1.056 SG), and up to 3.5–4.5 BTU/hr/gal for high-gravity imperial stoutery or fruit wine musts.
What size glycol chiller do I need for a 1-barrel (31-gallon) fermenter?
A 1/3 HP to 1/2 HP glycol chiller producing 2,500 to 4,000 BTU/hr is typically recommended for a single 1-barrel jacketed fermenter to support both peak fermentation cooling and rapid 24-hour cold crashing.
How does fermenter insulation affect cooling requirements?
Insulating a stainless steel tank with 2 inches of closed-cell polyurethane foam reduces the overall heat transfer coefficient (U-value) from ~1.4 BTU/(hr·ft²·°F) down to ~0.12 BTU/(hr·ft²·°F), cutting ambient heat ingress by over 90% and saving substantial compressor electricity.
What PID controller hysteresis should I use for fermentation cooling?
Set your temperature controller hysteresis (deadband) between 0.5°F and 1.0°F (0.3°C to 0.5°C). Setting the deadband tighter than 0.3°F can cause rapid short-cycling of the glycol solenoid valve or compressor, causing premature equipment failure.