Cluster hops, which accounted for over 90% of US hop production from the end of Prohibition to the 1970s, were America’s longest-continuously grown commercial hop variety. The hop is known for its vigor, and the pellets are prized for their excellent storability.
Despite its popularity in the past, Cluster’s popularity has decreased as craft beer enthusiasts seek out more fruit-forward hops. However, Cluster remains a valuable option for brewers, providing clean, neutral bittering with floral, herbal, and spicy flavors and aromas. It is suitable for use in ales, lagers, porters, and stouts where a clean bittering canvas is desired to showcase the malt flavors.
|Country of Origin:||United States|
|Hop Growers Code:||CLU|
Where To Buy Cluster Hops
Cluster Flavor And Aroma
Cluster is a dual-purpose hop that is often described to have the following aroma characteristics:
Cluster Hop Oil Breakdown
Hop oils can vary from year to year and farm to farm but based on our research, here are the typical values we have seen reported. This information comes from various hop farms, The Hop Aroma Compendium, and For The Love Of Hops.
|Alpha Acid % (AA)|
Alpha acids are what is isomerized when boiling to create bitterness in beer.
|5.5% – 9%|
|Beta Acid %|
Beta acids are what give hops their more aroma and flavor compounds.
|4% – 6%|
This ratio of alpha acids to beta acids determines how quickly bitterness fades during aging. Lower ratios are common for aromatic varieties.
|1:1 – 2:1|
|Co-Humulone as a % of Alpha|
Higher numbers are said to impart a harsher bitterness.
|36% – 42%|
|Total Oils (mL/100g)|
With more total oils, typically comes a more complex hop profile but these are highly volatile compounds.
|0.4mL – 0.8mL|
|38% – 55%|
|15% – 20%|
|6% – 10%|
|0% – 1%|
|Other Oils: Includes beta-ionine, beta-pinene, limonene, linalool, geranoil & selinene||23% – 39%|
|Hop Storage Index (HSI)|
The HSI indicates the percent of alpha and beta acids lost after 6 months of storage at room temperature (68°F or 20°C).
|Retains 80%-85% alpha acid after 6 months storage at 20ºC (68ºF).|
|Hop Storage Index (HSI) Rating||Great|
Cluster Hop Substitutions
Replacing one hop for another is seldom straightforward but sometimes you don’t have the right hop or the right quantity of hops for the beer you want to make. For those situations, we have made a comprehensive list of hops to substitute on brew day.
These substitutions aren’t perfect as hop chemistry is pretty complex.
We wanted to make this list of substitutions with varietals that are easy to find when possible. For Cluster, we recommend substituting with the following hops:
For the most part, any hop could have a place in just about any beer style. Based on popular beers, historical usage, and our own preferences, we would recommend using Cluster for IPA, New England IPA, Pale Ale, Wheat Beer, Golden Ale. That being said, experiment and see what works best for you.
Hieronymus, Stan. For The Love of Hops. Brewers Publications, 2012
The Hop Aroma Compendium. 2012