Barista Magazine

JUN-JUL 2018

Serving People Serving Coffee Since 2005

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easily with other substances around it, and is used often to displace oxygen, which degrades substances and causes them to go stale; this is why many coffee bags are fl ushed with nitrogen. The presence of nitrogen helps keep coffee fresh and is often used in kegged cold brew to preserve fl avor. The nitrogen doesn't react with the coffee itself, so it leaves the coffee intact. The term "nitro coffee" as we've grown accustomed to using it in specialty coffee is somewhat misleading. The foamy beverage, compa- rable to a Guinness or other nitrogen-conditioned beers, undergoes a pressurized conditioning process with, generally, a 30-percent carbon dioxide/70-percent nitrogen blend, which is referred to as a beer gas blend. Carbon dioxide, or CO ² , is naturally more soluble with liquids, which is how this type of coffee achieves a frothy texture. Usually, the coffee and gas blend has to undergo a conditioning process that takes at least a few hours or as much as 24 hours before the coffee is ready to serve. "Nitro coffee usually needs some time to condition and allow some nitrogen to dissolve into solution, since nitrogen has a somewhat tough time dissolving into water-based liquids. This gives a better head, as the dissolved nitrogen comes out of solution and creates bubbles when it hits normal atmospheric pressure," says Steve. Although Steve recommends a few hours of conditioning before serving, he's seen success using varying lengths of time. "Our (fastest turnaround time with conditioning was about an hour, with lots of gentle shaking of the keg after it had been pressurized … For best results, you should allow about 3–4 hours to condition at a minimum, but often it's easiest to go overnight, or keg in the morning to serve in the afternoon." On the other hand, regular kegged cold brew can be served immediately since it doesn't depend on any chemical reactions. Both beverages still use nitrogen when being served (when you peek into a keg cold-brew fridge, you'll usually see a nitrogen tank with a regulator on top to control the PSI, or pounds per square inch, of nitrogen being applied to the kegged coffee. Standard cold brew needs about 3–6 PSI of nitrogen per 5-gallon keg versus nitro cold brew, which needs 30–40 PSI. The reason nitrogen is overwhelmingly used in the kegged cold-brew process is because it doesn't alter the fl avor of the coffee. "Any gas mixed with CO ² will add some carbonic acidity to the coffee over time, which typically can be overpowering and abrasive; even a small amount of carbonation can have a dramatic impact," says Daniel Suh, cofounder of Provision Coffee in Phoenix. "Pushing with oxygen via a pump will expose coffee to rapid oxidation and will dramatically reduce fl avor and shelf life of the coffee." What does kegging do? Now that we understand the science, what does kegging do to coffee? "Because nitrogen is inert, kegging cold coffee can actually extend its peak fl avor and shelf life by displacing the oxygen that can cause off-fl avors to form," Steve says. "Where before your cold brew may taste skunky or stale after a couple days in the fridge, kegged cold brew could taste its best for up to a week, or more." No matter if you serve a little or a lot of cold brew in your café, kegging can help preserve the fl avor and extend the shelf life of your coffee. One of the most popular reasons for kegging cold brew is ensuring consistency for a roaster or wholesaler looking to provide their cold brew to a number of locations. "Kegging cold brew allows a coffee company to control the end product, ensure quality control and consis- tency, lengthen shelf life, offer a solution for wholesale clients unable to cold brew, and allows scalability," Daniel says, speaking from his ex- perience working with wholesale customers. For any company looking to sell premade cold brew, especially those with their name attached to the product (many coffee companies sell or provide their wholesale accounts with custom tap handles), ensuring that every cup served tastes the same is essential to a strong partnership with the client, and the solidifi cation of brand recognition. Kegged cold brew also allows for seamless high-volume situations, especially "where you're going through a lot of cold brew over the course of a relatively short period of time," says Liz Turner, director of West Coast events for Stumptown Coffee Roasters in Portland, Ore. Liz and her team set up booths for events across the nation, most recently at this year's South by Southwest in Austin, Texas, where thousands of thirsty concert-goers sought out Stumptown's stand for cold brew every day. "Cold-brew kegs are a lifesaver for us at busy music and culinary festivals, where we're pouring [thousands of] cold brews over the course of a few days," Liz says. "They're effi cient to ship and store, and we use recyclable kegs so they're way lower waste than cans or bottles, and much cleaner to deal with than pitchers." Plus, managing product is as easy as ensuring you have a cold fridge and the right gas hookups to keep coffee fresh. "As long as the coffee is kept cold and under pressure … the shelf life is identical to or better than other methods of cold-brew storage," says Liz. Common misconceptions about kegging 1: Getting coffee into a keg is difficult (read: impossible) This is usually the fi rst sticking point when it comes to making the jump into kegging, but it really shouldn't be. We like to say, "If you can fi ll a pitcher, you can fi ll a keg." It should be noted that there are two common types of kegs: • Cornelius (or "corny") kegs: These have a removable lid that gives access to make opening/cleaning/fi ll- ing an easy process. • Sanke kegs: These are commonly used in the beer industry and require more specialized equipment to clean/fi ll/etc. 2: I need electricity to operate a draft system This is a common misconception because many want to start by testing cold brew and/or nitro coffee at events and assume that electricity is needed to operate a draft system. Though you don't need electricity to operate the draft system, you will need electricity if you want/need to power a kegerator, refrigerator, or other cooling system to keep your coffee kegs cold. —Brendan and Cary Hanson, Keg Outlet 84 barista magazine

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