Why reiterated mash improves gravity without long boils

In our latest issue, Louisville’s Atrium Brewing scored a category-leading 98 for their barrel-aged stout Denny-Lou, Blend 1, and that was as good a reason as any to check in with cofounder Mark Rubenstein and head brewer Spencer Guy for some background on brewing stouts. Their proximity to some of the best distillers in the Western hemisphere informs their approach to both aging and blending, and they take the same iterative approach to building flavor in more ingredient-laden beers.

In this episode, they touch on:

• brewing flavored imperial stout as well as barrel-aged stout
• using a reiterated mash in lieu of longer boils for higher starting gravity
• building lower color stout with very low bitterness to let coffee shine
• balancing sweetness with tannins in barrel-aged stout
• blending with multiple stout threads
• the impacts of brandy and bourbon barrels
• kettle souring with a hazy IPA grain bill
• using probiotic beverages for kettle souring
• adjusting acids in the brite tank for proper fruit expression
• choosing fruit formats for clarity and quality
• spinning tanks then bench testing between each ingredient addition to confirm quantities with sensory
• constructing fruit blends and highlighting with yogurt

This episode is brought to you by:

G&D Chillers (https://gdchillers.com): G&D Chillers Elite 290 Micro-series line utilizes a natural refrigerant, features a more compact design with variable speed fans, and offers near-zero global warming potential. The future of sustainable refrigeration is here! Learn more about G&D’s Elite 290 line and visit GDCHILLERS.COM.
Berkeley Yeast (https://berkeleyyeast.com). Stop worrying about diacetyl with Berkeley Yeast’s line of Fresh™ strains. These revolutionary yeast strains are engineered to produce the ALDC enzyme inside the cell, preventing diacetyl before it forms. That means no more lengthy diacetyl rests—just clean, crisp beer that’s ready for packaging sooner. Learn more at berkeleyyeast.com/fresh.
Old Orchard (https://www.oldorchard.com/brewer): As breweries expand beyond beer into other segments like mocktails and CBD beverages, Old Orchard is here to help. Whether trending flavor additions or nostalgic favorites, the next best thing is around the corner at Old Orchard. More information and free samples are waiting at oldorchard.com/brewer
Indie Hops (https://indiehops.com) Strata, Indie’s original hop release, is now available in cold-side flowable hop oil form—Strata HyperBoost—in coordination with Yakima Chief Hops. Indie Hops T90 pellets establish the multi-layered Strata experience, while cryogenic CGX pellets in coordination with Crosby Hops, and now Strata HyperBoost with YCH expand the possibilities. Learn more about Strata and Indie’s more recent hop releases at www.indiehops.com.
Ss Brewtech (https://www.ssbrewtech.com) Featuring a laser-welded cooling jacket for efficient and precise temperature control, an innovative silicone racking arm, and a carbonation stone that allows you to carbonate right in the fermenter, Unitank 2.0 is engineered to help you get the most out of your fermentations! Visit Ss Brewtech.com to learn more!
Isuzu Trucks (https://www.isuzucv.com) Whether you are looking for a self-distribution solution or one to deliver supplies, there is an Isuzu truck that will fit your needs. Go to isuzucv.com to check out their impressive lineup or visit an Isuzu dealer today to find out why now, more than ever, Isuzu trucks are the trucks you trust for the work you do!
Cytiva (https://info.cytivalifesciences.com/sample-request-brewing.html) Protecting your beer’s highest quality is crucial to maintain its unique taste and prevent spoilage organisms, and microbiological testing plays a vital role in this process. Cytiva offers a comprehensive portfolio of laboratory filtration products designed for both lab and production-floor use.
Brewer's Retreat (https://brewersretreat.com) Tickets for the Craft Beer & Brewing 2025 Brewer’s Retreat in Asheville and Mills River, North Carolina are on sale now and going fast. Brew on homebrew systems with some of the most inspiring craft brewers in the U.S. Learn more and secure your tickets at brewersretreat.com

Support Craft Beer & Brewing Magazine Podcast