Hop Extract Use in Beer
The good, the bad and the ugly
One of the best aspects of traveling to Germany
is sampling a variety of beers in their native habitat. Germany has a
rich tradition when it comes to beer and one trend I have witnessed over the
years is an ever increasing use of hop extract (or hopfenextrakt) in their traditional
beer. It’s boarding on ubiquitous for
the big brands but now the regional and smaller breweries are getting into the
act. It got to the point to where reading hop extract
listed on the ingredients started to give me the same level of disappointment
as seeing "truffle oil” listed on a restaurant’s menu (but at least there are
hops in hop extract).
Upon returning the USA, I was determined to learn as much as I could about hop extract to try to explain the increased use I witnessed in Germany. I found a little bit of information in a lot of places. This post is put together as a repository for the info I found.
What is hop extract?
In a nutshell, hop extract is a condensed form of the alpha acids, the beta acids, oils and resins found in hops. It is made by taking hops and processing them using one of the following methods to create an extraction:
1. Kettle Extract
Hops are mixed with a polar solvent (e.g., hot water) and hop tea is produced . The hot tea is cooled, the PH is adjusted and then washed with hexane. Once washed multiple times, the PH is adjusted again. This can produce a light stable kettle hop extract that can be added to beer and help prevent skunking.
2. CO2 Extract
Hops are added to a sealed chamber and the chamber is then injected with liquid CO2. The chamber is heated and the liquid carbon dioxide boils and strips the acids, resin and oils from the hops. The carbon dioxide is then vented and allowed to evaporate leaving the hop extract and hop solids behind.
3. Ethanol Extract
Ethanol extract is made simply by mixing hops with alcohol and allowing the mixture to macerate or steep. Then the mixture is strained and the alcohol is strained or pressed from the hops. The alcohol acts as a solvent and removes the hop oils, acids and resins from the hop solids and places them in the solution. This is how many cocktail bitters are produced including hop bitters.
4. Isomerized Hop Extract
Once the extract is made, it can be processed further to isolate functional molecules found in hops. The result is a range of products called Isomerized hop extract. Hop extracts do more than just concentrate the flavor found in hops. Once the extract is produced, the functional molecules in the hop extract can be separated and isolated by Isomerization. Isomerization isolates acids and oils found in hops. These include:
Alpha Acids (adds only aroma)
Beta Acids (add only bitterness)
di-hydroisoalpha acids (Rho)
(adds bitterness and improved foam character)
These extracts can be used in beer as designer ingredients and surgically alter bitterness, aroma, deliver anti-microbial activity, head retention, head cling (make the beer head cling better to the inside of the glass) or light stability.
Hop Extract use in Germany
Hop Extract and
German mega brands and even smaller region breweries are using hop extract more and more. Since these beers meet Reinheitsgebot (German Beer Purity Law), clearly hop extract is green flagged by the German beer bureaucrats. In 1968, Reinheitsgebot was amended to allow the use of hop extracts. Here are the current laws that govern the use of hop extract in German beer:
Current German Beer Laws
Hop powder, hops in other milled forms and hop extracts may be used in brewing, so long as these products comply with the following requirements:
- Hop powder and other milled hop forms, as well as hop extracts must be produced exclusively from hops.
- Contribute the same flavoring and bittering substances to the wort as would have been contributed had hops been simmered with the wort.
- Fulfill the requirements of the German Pure Food Laws.
- Only be added to the wort before or during the simmering phase.
Hop Extract Use in the USA
The FDA is the federal agency tasked with regulating hop extracts. The following are few regulations specific to hop extracts and hop extract use:
Hexane is one of the solvents that can be used to make kettle extract. Hexane is commonly used in food processing to extract oils from grains and soy. Hexane can persist in the final food product after processing. The FDA allows hop extract to contain up to 25 ppm of hexane residue.
Hops extract, Methylene Chloride and Solvent Residue:
More on Hexane and Methylene chloride in Hop Extracts:
Organic Hop Extracts
It would seem that the only two production methods that might yield a hop extract that could be considered organic are Ethanol Hop Extract and CO2 Hop Extracts. You could macerate organically grown hops in organic ethanol and the result would be Organic Hop Extract. CO2 doesn't leave any residue so if you make an extract with organically grown hops, the resulting extract could be considered organic. Read this:
Observations on Hop Extract Use in the USA
US beer drinkers seem to be more accepting of hop extract use when compared to beer folks in Europe. This is true both with craft beer drinkers and drinkers of the mass produced adjunct lagers. Why is this? Here are my theories:
- Ballantine Ale reportedly used an ethanol hop extract in an older recipe so there is a long track record of using extracts in America.
- Some great craft brewers create exceptional beers using hop extract. Russian River makes a Triple IPA called Pliny the Younger that uses hop extract in conjunction with dry hops. This is done to increase the IBUs without increasing the amount of wort sucked up by adding dry hops. I wouldn't consider this a short cut and if the extract used is ethanol or CO2 derived, this makes perfect sense.
- Some (NOT all) craft beer drinkers equate high IBUs to high quality (same can be said for high ABV). If hop extract achieves a hoppier beer, then the use must be a good thing, right? Not so much. This viewpoint can overlook some of the not-so "crafty" aspects of kettle and isomerized extracts.
Hop Extract Use: Pros
Hop extract is used in beer for many different reasons. This includes the following:
- Added additional IBUs to the beer without jamming additional pellets or plugs into the brew kettle. High IBU beers may need to use extract for efficiency purposes.
- Some types of hop extracts can be added before or after the fermentation processes. This can helpful to create a more consistent product. You can basically touch up a beer after fact and this gives the brewer more control over the finished product.
- Isomerized hop extract allows the brewer to pick and choose the desired qualities found in hops. Hops do a lot for beer. Isomerized hop extract creates an ala carte system. Needs only bitterness? Want to put the beer in green bottles and want the beer to be light stable? Or, perhaps the head needs to look or act a specific way. All can be achieved by using Isomerized hop extract.
- Hop extract can be used in place of dry and wet hops. Hops are a commodity and are subject to harvest and market conditions and don’t have a particularly long shelf life. Hop extract takes up a fraction of the space in a brewery and produces only empty containers was a waste byproduct. This can save money and space.
- Hops extracts minimize kettle foaming.
- Multiple Beers from a Single Fermentation. Post fermentation hop extracts allow brewers to take one fermented product and create multiple beers by adding differing hop extracts.
- Hop extract allows brewers to create beers with qualities that traditional use of hops simply won’t allow.
- Nitrates, heavy metals and pesticide residue that may be present on unprocessed hops are removed during the extraction process.
- Help reduce skunked beer. When hops are added to the brewing process and heated, alpha acids in the hops are isomerized creating the potential for skunking if the finished product is exposed to light. The isomerized alpha-acids in some forms of hop extract have been altered to remove the alpha-acids required in the skunking process.
- Reduces wort losses that might be absorbed by dried hops.
Hop Extract Use: Cons
- Non-Traditional brewing method and if used improperly, can make for a bad tasting beer.
- Replacing all the hops with hop extracts. Extracts strip away certain characteristics in hops that add complexity to the flavor. For instance, bittering hops may also lend slight aroma to beer. Replacing bittering hops with extract strips away this added flavor.
- Aroma qualities found in hops are negatively impacted during the extraction process. The higher the temperate used to make the extraction increases the loss of aroma.
- Hop extracts have a fraction of the prenylflavonoids found in non-processed hops. “When hop extracts (carbon dioxide) or advanced hop products are used low or negligible amounts of prenylflavonoids are found in the final beers.”
Prenylflavonoids appear to have anticancer properties.
- Hop extracts can have a slightly higher cost per bitterness unit compared to whole hops or pellets.
- Kettle and Isomerized Hop Extract are a chemically processed product. This diminishes the “farm-to-table” aspect of some craft beers. The residue from some of the solvents used in the extract process are carried over into the extract and, in turn, the beer.
- Labeling. If hop extract is listed in the ingredients, you don't know if the extract is chemically processed or an ethanol or CO2 extract.