BarthHaas September 2021 Hop Science Report

Dr. Christina Schoenberger of BarthHaas has searched the world of hops and brewing to bring you the latest news and research. See the September 2021 report summary below.

Nitrate is a naturally occurring ion in living organisms. Due to its high water solubility, nitrate is extracted out of hops which can result in high concentrations in beer. US researchers investigated the transfer rates of nitrate from hops into beer during kettle, whirlpool and dry hopping. They found that dry hopping results in the largest increase in nitrate, followed by whirlpool additions, then kettle hop additions.

Hop creep is an important phenomenon for brewers to understand when they are creating hop-forward beers. When hops are added during fermentation or maturation, hop diastatic enzymes can still be active and may convert beer dextrins to fermentable carbohydrates. Yeast cells can then ferment these carbohydrates to carbon dioxide and ethanol, compromising beer quality. German researchers have found that total mono hexoses is a reliable and reproducible method for quantifying the diastatic activity of hops.

The presence of high concentrations of organic acids in sour beers is known to adversely affect the efficiency and quality of ethanol fermentation. The growing popularity of this beer style warranted US researchers to explore yeast strain-specific performance. The study confirmed the suitability of active dried yeast for sour beer fermentations that meet or exceed the typical acid concentrations encountered in sour wort containing < 0.4% w/w lactic acid or < 0.1% w/w acetic acid.

Upcoming events:

Hard Seltzer: Overview & Classification

Webinar, 14 October 2021

Learn why hops absolutely belong in hard seltzer.

Hop Flavour Impact

Webinar, 27 October 2021

Evaluate and create hop flavour in your beer.

Hop Creep

Webinar, 8 November 2021

What is hop creep and why does it scare brewers?

Hop Selection

Webinar, 17 November 2021

From the hop field directly to your home.


If you would like to discuss any of these studies or events further, please get in touch.


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