Home
Back
Grain Formula:
| From: | To: |
The grain calculation formula determines the amount of grain needed for beer brewing based on volume, target gravity, brewing efficiency, and the extract potential of the grain. This calculation is essential for recipe formulation and consistency in homebrewing and professional brewing.
The calculator uses the grain formula:
Where:
Explanation: This formula calculates the pounds of grain needed to achieve a specific gravity in a given volume of beer, accounting for your system's efficiency and the grain's potential extract.
Details: Accurate grain calculation is crucial for achieving target beer characteristics, consistency between batches, cost control, and efficient use of brewing ingredients. It helps brewers create balanced recipes and predict final beer properties.
Tips: Enter batch volume in gallons, target gravity in points (OG-1000), brewing efficiency as a decimal (e.g., 0.75 for 75%), and the grain's extract potential. Typical extract potentials: base malts 36-38 points/lb/gal, specialty malts 25-35 points/lb/gal.
Q1: What is gravity in points?
A: Gravity points represent the specific gravity minus 1000. For example, a specific gravity of 1.050 equals 50 points.
Q2: How do I determine my brewing efficiency?
A: Efficiency is calculated by comparing the actual extract obtained to the theoretical maximum. Most homebrew systems range from 65-80% efficiency.
Q3: What are typical extract potential values?
A: Base malts typically have 36-38 points/lb/gal, while specialty malts range from 25-35 points/lb/gal. Check with your malt supplier for specific values.
Q4: Can I use this for extract brewing?
A: This calculator is designed for all-grain brewing. For extract brewing, you would calculate based on extract potential of dry or liquid malt extract.
Q5: How does water volume affect the calculation?
A: The calculation uses the final batch volume, which already accounts for water absorption by grain and boil-off rates.