1. What is the Beer Gravity Equation?

The Beer Gravity Equation estimates the final gravity of beer based on original gravity, alcohol percentage, and a conversion factor. It helps brewers predict and control the fermentation process.

2. How Does the Calculator Work?

The calculator uses the Beer Gravity equation:

Where:

• \( Original\ Gravity \) — Starting specific gravity before fermentation (SG)
• \( Alcohol\ \% \) — Alcohol by volume percentage (%)
• \( Factor \) — Conversion factor (typically 131.25 for most beers)

Explanation: The equation accounts for the relationship between alcohol production and sugar consumption during fermentation.

3. Importance of Gravity Calculation

Details: Accurate gravity estimation is crucial for brewers to determine fermentation completion, alcohol content, and beer sweetness.

4. Using the Calculator

Tips: Enter original gravity in SG units, alcohol percentage, and factor (default is 131.25). All values must be valid (OG > 1, alcohol ≥ 0, factor > 0).

5. Frequently Asked Questions (FAQ)

Q1: What's a typical original gravity range?
A: Most beers range from 1.030 (light lagers) to 1.120 (barleywines) SG.

Q2: Why is the factor typically 131.25?
A: This empirical factor accounts for the average relationship between alcohol production and gravity change during fermentation.

Q3: When should I measure gravity?
A: Measure original gravity before fermentation and final gravity after fermentation appears complete.

Q4: Are there limitations to this equation?
A: Less accurate for very high-gravity beers or unusual fermentations with non-standard attenuation.

Q5: How does temperature affect gravity readings?
A: Hydrometer readings should be temperature-corrected - most are calibrated to 60°F (15.5°C).