1. What is Brewing Attenuation?

Attenuation in brewing refers to the percentage of sugars that are converted to alcohol and carbon dioxide by yeast during fermentation. It indicates how completely the yeast has fermented the wort.

2. How Does the Calculator Work?

The calculator uses the attenuation formula:

Where:

• \( OG \) — Original gravity (dimensionless)
• \( FG \) — Final gravity (dimensionless)

Explanation: The formula compares the drop in gravity from original to final against the potential maximum drop (OG - 1).

3. Importance of Attenuation Calculation

Details: Attenuation helps brewers understand yeast performance, predict alcohol content, and diagnose fermentation problems. Different yeast strains have characteristic attenuation ranges.

4. Using the Calculator

Tips: Enter original and final gravity values (typically between 1.030-1.100 for OG and 1.000-1.030 for FG). Both values must be greater than 1 and OG must be greater than FG.

5. Frequently Asked Questions (FAQ)

Q1: What is typical attenuation for different yeast types?
A: Ale yeasts typically attenuate 65-80%, lager yeasts 70-85%, and high-attenuation Belgian strains up to 90%.

Q2: How does attenuation relate to alcohol content?
A: Higher attenuation means more sugar converted to alcohol, resulting in higher ABV for the same OG.

Q3: What causes low attenuation?
A: Possible causes include unhealthy yeast, insufficient nutrients, low fermentation temperature, or unfermentable sugars.

Q4: What's the difference between apparent and real attenuation?
A: This calculator shows apparent attenuation. Real attenuation accounts for alcohol's effect on hydrometer readings and is about 20% lower.

Q5: Can attenuation be too high?
A: Yes, over-attenuation can lead to thin body and off-flavors. Some styles benefit from residual sweetness.