[app. a. Du koelbak, f. koel cool + bak BACK sb.2] = COOLER 2: esp. in a brewery. Obs.
1708. Mortimer, Husb. (ed. 2), 572. Your first Wort being thus boiled, must be pumped or laded off into one or more Coolers or Cool-backs, in which leave the Sullage behind, and let it run off fine.
1727. Bradley, Fam. Dict., s.v. Brewing, Let it run from your cool-backs into your Tun very cool.
