What is CO2 hop extract and how do you brew with it? Experts at BSG explain

This article from the BSG Hops Team was first published on BSG’s excellent blog. BSG supplies craft brewers, winemakers, home fermentation retailers, craft distillers and cider makers throughout North America with premium ingredients from malt and hops to yeast and processing aids. The BSG CraftBrewing division is specifically focused on serving indie brewers.

CO2 hop extract is a great brewing tool. It is a pure resin produced through supercritical CO2 extraction, whereby the essential bittering and aromatic compounds of hops (alpha acids, beta acids and oils) are separated from the leafy plant material. The extraction process removes solids, while the CO2 is recovered and reused. The final resin is then analyzed for brewing values and packaged in ready-to-use food grade cans.

“We use hop extract for our highly-hopped, West Coast-style IPAs,” explains Dan “Gus” Lehnerer, founder and head brewar at New Oberpfalz Brewing in Griffith, Ind. “From a process standpoint, we see a number of benefits: better wort yield to the fermenter as well as higher finished beer yield, plus reduced PHE [plate heat exchanger] clogging due to hop solids, which in turn means faster cooling times and reduced cooling water consumption. From a sensory standpoint, we get a more pleasant bitterness with lower astringency than using pellets for bittering these recipes.”

The benefits of brewing with CO2 hop extracts are many and varied:

• Increased kettle and FV yields through reduced trub
• Increased hop utilization from early boil additions
• Variety-specific hop character when used in whirlpool
• Improved shelf stability vs. pellet and whole cone hops
• Reduced kettle foaming during the boil
• Reduced polyphenol flavor contribution from plant material
• Reduced shipping costs
• Reduced storage space requirements

“CO2 extract allows us to make IPAs that have more hop character without loss on the hotside,” explained Whit Baker, cofounder and brewmaster at Bond Brothers Beer Co. in Cary. N.C. “We can use a smaller amount of neutral, high alpha, bittering hop to achieve higher yield on a beer with even more hop character.”

Brewing with CO2 hop rxtracts

For ease of use, we recommend formulating recipes to use CO2 hop rxtract in entire can increments. One method for adding extract to wort is to place an open or perforated can in the grant during runoff. Another method is to dissolve the extract in hot water or wort in a separate vessel or container, and then add the mixture to the boil or whirlpool. Another common method is to suspend cans in kettle during the boil using a basket.

CO2 hop extracts require wort boiling to isomerize their alpha acids. Early kettle additions (~ 60 minutes of boil time) will lead to an alpha acid utilization of approximately 35 precent. Actual utilization is dependent on equipment, process and recipe specifics, and bitterness contribution should be confirmed through lab analysis of wort or beer.

“In our efforts to make the best IPAs we can, as well as recover the most amount of liquid to package for sale downstream, I am a big fan of utilizing CO2 extracts for usage on my hotside additions, alongside T-90 and Cryo products, to get a nice multi-modal presentation of the hop varietals in our IPAs,” said Jared Lewinski, head brewer at Listermann Brewing Co. in Cincinnati, Ohio. “My only complaint regarding CO2 extracts are that it is hard to find some of the more desirable varieties, so I’d love to see those more readily available!”

Late kettle or whirlpool additions of CO2 Hop Extracts will yield variety-specific flavor and aroma contribution.

Grams of Alpha Acid = gma

The unit of measure for BSG’s CO2 Hop Extracts is grams of alpha acid (gma) – a 150 gma can contains the resin extracted from 2-6 pounds of hops.

Calculating Bitterness

The following formula can be used to calculate estimated bitterness when using CO2 Hop Extract. IBU contribution is dependent on equipment, process, and recipe specifics, and bitterness contribution should be confirmed through lab analysis of wort/beer.

For more info, we highly suggest visiting the hop extracts page of BSG’s website for an online calculator to easily determine required gma. Contact your sales manager for more information or assistance. The results speak for themselves.

“I started using hop extract specifically for sensory reasons,” said John Dean, brewmaster at Blind Tiger Brewery and Restaurant in Tokoeka, Kan. “I wanted to reduce the plant matter flavor in our highly-hopped beers, and I’ve been very happy with the results. The yield improvements have been a nice bonus. I’ve also used these variety-specific hop extracts alongside pellets for mid-boil flavor/aroma additions.”

This was expertly written by the BSG Hops Team. Learn more here.