Mark Deming and Olin Nelson are data analyst guys who work in the same office and love, love coffee. Deming, 30, can gulp down three pots a day. Nelson, 26, experiments with cold brewing coffee at his South End apartment and brings gallons to the office for his colleagues to test out. His trial runs are a hit. This is how the two got together recently to launch Commonwealth Coffee Co. They use CommonWealth Kitchen in Dorchester to craft bold, smooth, and flavorful cold-brew coffee they sell in dark amber apothecary-style bottles ($4-$5 for 8 ounces). It’s made with organic, fair-trade coffee beans from around the globe, roasted at microroasters Hogan Brothers Coffee in Framingham. The coarse grounds are steeped in cold water for 24 hours in stainless steel barrels. The process extracts flavor, lowers acidity, and ramps up the caffeine. Their flagship, Beantown Blend, made with Colombian beans, is strong with pleasant hints of hazelnut; another choice, Festivus, is infused with chocolate and vanilla. Other selections are rotating seasonal flavors brewed with herbs and spices. The duo also offers 5-gallon kegs filled with cold brew. Employers are thrilled, Nelson says, because people don’t now dash out of the office to grab coffee. Cold brew bottles are available at American Provisions, 613 East Broadway, South Boston, 617-269-6100; Formaggio Kitchen, 244 Huron Ave., Cambridge, 617-354-4750, and Formaggio Kitchen South End, 268 Shawmut Ave., Boston, 617-350-6996; and The Vin Bin, 91 Main St., Marlborough, 508-480-9463. For kegs, go to www.commonwealthcold brew.com.ANN TRIEGER KURLAND

Ann Trieger Kurland can be reached at atrieger@comcast.net.