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EXOGENOUS ENZYMES

UNLOCKING YOUR GRAIN’S POTENTIAL WRITTEN BY GABE TOTH

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or distillers who are looking to increase yield, improve flow, or just shorten their conversion times, exogenous enzyme producers often have a solution. Historically, spirit production has relied solely on naturally occurring grain enzymes, often leaning on the higher enzyme content of six-row barley to convert corn, rye, rice or other starch sources that can’t self-convert. Tworow barley has enough diastatic power, or capacity to convert starch, to selfconvert, making it a natural choice for malt whiskey and beer. Further, added enzymes are prohibited in some styles and regions, such as in Scotch whisky production. However, a variety of exogenous enzymes (those not resident in the grain already) allow distillers to tailor their approach to specific conditions and let them target particular problems they may be experiencing. “For some distilling processes, all the enzymes are coming from your malt,” Kerry Technical Sales Manager Chris

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Limmex said. “If you’re using purified enzymes in place of the malt or (in place of) some of the malt, you’re keeping the activity the same from batch to batch. Barley enzymes can vary crop to crop.” Kerry Brewmaster Chika Ezeani describes exogenous enzymes as a “complement” to existing malt enzymes. “It gives you the flexibility, it increases your turnaround time. Most distillers use malt plus exogenous enzymes as tools to improve processes.” For distillers who have to cook grain to gelatinize starch, a high-temperature amylase enzyme allows saccharification to begin during cooking. Amylase from barley malt has a temperature range below that of the gelatinization range, so a cooked mash has to be cooled down before adding the barley, otherwise the amylase will denature. “Some of the exogenous enzymes can extend that range. You can process at higher temperatures, up to 200 degrees,” according to Limmex. “The real benefit would be to extract at high temperatures. You can speed up your processes by

using Hitempase. “You can also use Convertase or amylase to increase that extract yield if there is a high percentage of stuff there that isn’t being broke down,” he explains. Because malt amylase’s ability to break down starch—essentially long chains of glucose molecules—is limited, exogenous enzymes offer an opportunity to increase the amount of sugar pulled from the same amount of malt. Malt amylose, in particular the highertemperature alpha amylose, leaves a significant percentage of malt sugars in an unfermentable form. Most of it will be broken into fermentable one-, two-, or three-glucose groups—glucose, maltose, and maltotriose—but the rest will be more than four glucose molecules or contain a branch where the glucose chain splits. Those otherwise unfermentable dextrins can be broken down completely by amyloglucosidase (referred to by the brands Convertase or Amylo), which takes everything down to simple glucose. Because amyloglucosidase converts methodically, working from the end of

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Artisan Spirit: Spring 2018  

The magazine for craft distillers and their fans.

Artisan Spirit: Spring 2018  

The magazine for craft distillers and their fans.