No, old beer does not get stronger.
Based on the provided information, the alcohol content of beer does not change over time. This means that a beer's strength, which is determined by its alcohol percentage (ABV - Alcohol By Volume), remains constant as it ages.
Aging beer can affect its flavor, aroma, and overall quality, sometimes in desirable ways for certain styles, but it does not increase the amount of alcohol present in the liquid. The fermentation process, which creates the alcohol, is completed before the beer is packaged. Once bottled or canned, the alcohol level is stable.
Understanding Beer Strength
Beer strength is measured by its Alcohol By Volume (ABV) or sometimes Alcohol By Weight (ABW).
- ABV: This is the standard measurement, indicating the percentage of total volume that is pure alcohol.
- ABW: This measures the percentage of total weight that is pure alcohol (less common).
The conversion is roughly ABV ≈ ABW * 1.25.
Regardless of which measure is used, this percentage is determined during the brewing and fermentation process.
What Happens to Beer as It Ages?
While the strength doesn't change, other characteristics do.
- Flavor: Flavors can evolve. Some desirable aging notes include sherry-like, dried fruit, or malty characteristics. Undesirable flavors like cardboard (oxidation) can also develop.
- Carbonation: Beer typically loses carbonation over time, becoming "flat."
- Aroma: Aromas can change, often mellowing or developing new notes.
As the reference states, "Generally, it is safe to drink flat beer, as the alcohol content does not change over time and beer does not become unsafe to drink as it ages." This confirms that the primary effect of aging discussed here relates to carbonation and safety rather than increased strength.
Key Takeaway
The alcohol content of a beer is fixed at the time it finishes fermentation. Aging does not cause the alcohol level to rise. Therefore, old beer is not stronger than it was when it was fresh from a strength perspective.
| Aspect | Change with Aging | Note |
|---|---|---|
| Alcohol Content | No Change | Stays the same (e.g., 5% ABV remains 5%) |
| Flavor | Can Change | May improve or degrade depending on style and storage |
| Carbonation | Decreases | Beer often becomes flat |
