Alpha acids are a class of compounds primarily of importance to the production of beer. They are found in the flowers of the hop plant and are the source of hop bitterness. Alpha acids may be isomerized to form iso-alpha acids by the application of heat in solution. Iso-alpha acids are typically produced in beer from the addition of hops to the boiling wort. The degree of isomerization and the amount of bitter flavor produced by the addition of hops is highly dependent on the length of time the hops are boiled. Longer boil times will result in isomerization of more of the available alpha acids. The alpha acid "rating" on hops indicates the amount of alpha acid as a percentage of total weight of the hop. Hops with a higher alpha acid content will contribute more bitterness than a lower alpha acid hop when using the same amount of hops. High alpha acid varieties of hops are more efficient for producing highly bitter beers.
For example, this list shows a number of hop varieties with the highest percentages of Alpha Acids typically found in each variety (percentages are based on total dried weight). Alpha acid percentages may also vary within specific varieties depending on growing conditions, drying methods, age of the hop, and other factors.
- BULLION 11%
- CASCADE 8%
- CENTENNIAL 11.5%
- CHINOOK 14%
- CLUSTER 8.5%
- CRYSTAL 5%
- EAST KENT GOLDINGS 7%
- EROICA 14%
- FUGGLES 5.5%
- GALENA 14%
- HALLERTAUER HERSBRUCKER 5%
- HALLERTAUER MITTELFRUEH 5%
- LIBERTY 6%
- MT. HOOD 8%
- NORTHDOWN 9.95%
- NORTHERN BREWER 8%
- NUGGET 14%
- PERLE 9.5%
- SAAZ 5%
- STYRIAN GOLDINGS 7%
- SUMMIT 19.5%
- TARGET 12.5%
- TETTNANG 6%
- WILLAMETTE 6%
No comments:
Post a Comment