Fwd: Water make-up in Twin Cities area (Document)

From: Mike <mpv(a)yuck.net> Date: July 20, 2005 6:28:13 PM CDT To: sphbc(a)sphbc.org, mnbrewers(a)yahoogroups.com, Minnesota homeBrewers Association <mba(a)thebarn.com> Subject: Re: Water make-up in Twin Cities area (Document) I definitely encourage the exercise of collecting area water analysis from your local water departments. Most are happy to send you their data. MHBA has done this before, too bad we don't have the results published somewhere. Here's what you'll find: For the purposes of brewing, there are basically two types of water sources in the area: ground water (Mpls - Mississippi River, StP - lakes) and well water (the rest of us). The exception is Richfield which uses a combination (east - river, west - wells, but some places get both). For Mpls and StP, the water contains very little carbonate/bi- carbonate hardness ("temporary hardness") and adequate calcium and therefore needs little treatment for mashing and brewing. Boiling or carbon filtering to remove chlorine is about it. One could add various salts to duplicate famous water profiles (e.g., calcium sulphate to mimic Burton water), but that is unnecessary to achieve good mash chemistry in the mash tun. For the rest of us (and that goes for the greater upper midwest, not just the Twin Cities), water hardness is a function of how deep your well is, since pure water travels up through limestone, where it picks up calcium and carbonate. As I recall (admittedly not all that well), temporary hardness of 250-400 ppm is not uncommon in the twin cities. That may seem like a big range, but for our purposes treatment and the resulting water is the same. Boiling and then cooling the water causes the calcium to bond with carbonate/bi-carbonate and precipitate out as chalk. Decant the water off the chalk and you will have water with no calcium and about 50 ppm carbonate. That's little enough carbonate that you don't need to worry about the buffering effect in the mash tun. Simple add back enough calcium (in the form of calcium sulfate or calcium chloride) and the water fine for brewing most styles of beer. ----------------------------------------------------- Mike Valentiner, Minneapolis, MN