Brewhouse Efficiency Calculator

Brewhouse efficiency measures how well a brewing process extracts fermentable sugars from grain, expressed as a percentage and as a points per pound per gallon (PPG) figure. Four efficiency measurement types are supported: Conversion, Pre-Boil, Ending Kettle, and Brewhouse. Each measures extraction at a different stage of the process, which makes it possible to pinpoint where losses occur rather than seeing only a single combined number.

Wort volume is the amount collected at the measurement point in question; Conversion efficiency instead uses the total mash water volume, since it measures extraction from the mash itself rather than from collected wort. Gravity measurement is entered in standard 1.xxx format, and a hydrometer reading taken away from the calibration temperature needs a temperature correction first. The grain bill lists each grain's weight and its potential extract in PPG; common base malts run around 36 to 37 PPG, while specialty malts range from 25 to 35, so a grain bill heavy in crystal or roasted malts has a lower potential-points ceiling than the same weight of pale malt regardless of how well the mash converts it.

Actual Points equal (Gravity - 1) x 1000 x Volume. Potential Points equal the sum of each grain's weight times its PPG. Efficiency Percentage equals (Actual Points / Potential Points) x 100. For metric inputs, liters convert to gallons (1 L = 0.264172 gal) and kilograms convert to pounds (1 kg = 2.20462 lb) before the PPG-based formulas apply.

A grain bill of 10 pounds of base malt rated at 37 PPG goes into a 6-gallon batch that reads 1.046. Actual points are (1.046 - 1) x 1000 x 6 = 46 x 6 = 276. Potential points are 10 x 37 = 370. Efficiency is (276 / 370) x 100, about 74.6%, within the 70 to 75 percent range typical of an all-grain system.

Measuring efficiency at every stage of the process tracks and improves brewing over time. Comparing results across brew days isolates equipment upgrades, technique changes, or recipe adjustments that affect extraction.

• All-Grain Homebrewing: Measure brewhouse efficiency after transferring wort to the fermenter. Comparing actual efficiency to recipe assumptions, typically 70 to 75 percent, points to whether grain quantities need adjusting for future batches.
• Mash Optimization: Conversion efficiency evaluates how well the mash extracts sugars before any losses from lautering or boiling. A low conversion efficiency may indicate incorrect mash temperature, pH issues, or insufficient crush.
• Equipment Comparison: Tracking pre-boil and ending kettle efficiency separately isolates losses to specific equipment, showing whether a mash tun upgrade, a better sparge technique, or reduced dead space would have the greatest impact.
• Recipe Scaling: A known system efficiency lets grain bills be adjusted accurately when adapting recipes designed for a different system.
• Brew-in-a-Bag (BIAB): Conversion and brewhouse efficiency tend to differ from traditional three-vessel setups in single-vessel brewing, so tracking both shows improvement as squeeze technique or grain crush is refined.
• Competition Brewing: A known efficiency percentage predicts actual gravity from a planned grain bill before brew day, allowing preemptive adjustments to hit precise original gravity targets.
• Brewing Education: Seeing how gravity, volume, and grain potential interact in the step-by-step derivation builds intuition about extraction, with the formula substitution and intermediate values shown explicitly.