Someone recently asked me a few questions:
- I know there is some chlorine in the Vic tap water but I dont have a filter system. I was wondering if buying the filtered water at the grocery store would be good and then adding some gypsum to harden it.
- Ive never used any water hardener before, have read gypsum is good for hoppy beers and calcium chloride is good for malty ones.
- Would you suggest using gypsum for my next beer, an oatmeal stout. Would this also be good if brewing with Vic’s tapwater, which I know is very soft.
Victoria water is beautiful for brewing – just about a blank slate – but like all municipal water, it does have some chlorine but worse, chloramines (which do not volatilize (i.e., evaporate) out of the water with boiling or standing overnight). I refer to both chlorine and chloramines as ‘chlorine’ below.
I’ve been considering a high-flow, ‘whole house’ water filtration system to strip the chlorine out of my brewing water – they cost about $100 all-in from Home Depot. Important when choosing the filter is getting one that will actually filter out the chlorine (there are some filters that literally just filter out particulates rather than dissolved minerals). ‘Activated charcoal’ is what you need to get the chlorine. There’s no need for a water ‘softener’ (which exchanges calcium and magnesium with sodium) here in Victoria – we already have beautiful rain-fed, surface-sourced (as opposed to underground-sourced) ‘soft’ water.
The really easy and cheap solution to get chlorines out of your tap water is to use campden tablets (which are made of potassium metabisulfite or sodium metabisulfite). Pulverize and add them your water at a rate of one tablet to 20 gallons. It reacts with the chlorine and precipitates it out. I just add it to my HLT water and stir before I start heating.
Adding minerals like gypsum (calcium sulphate/CaSO4) and calcium chloride (CaCl2) (note: chlorine = bad, chloride = good) to your brewing water can really help your beer too. Calcium is valuable in the mash and is critical to good yeast flocculation. [These minerals will also affect your mash pH (that you want to be at about 5.2 whether you’re making a pilsner or a stout), but that’s an even more complicated discussion – see How to Brew by John Palmer]. Because Victoria’s water is very low in calcium, adding CaSO4 and CaCl2 can get that valuable calcium into your water. Then you can think of ‘seasoning’ the water (the same way you do with salt or sugar on food): accentuate the hoppiness by increasing the sulphate (SO4); accentuate the maltiness by increasing the chloride (Cl2).
Generally speaking, I end up adding between 10-20 grams of minerals to my 10 gallon batches (ultimately 15-17 gallons of water). The quantity and ratio I use depends on the kind of beer – if I’m making an IPA, maybe 15g CaSO4 and 5g CaCl2, if a helles, maybe 7g CaSO4 and 10g CaCl2. If making a stout, you may also want to add some calcium carbonate (CaCO3), which will compensate for the acidic nature of roasted grains. ‘How to Brew‘ will get you as deep into water and mash chemistry as you like. He has an Excel spreadsheet for calculating suggested salt additions (at the bottom of: http://www.howtobrew.com/section3/chapter15-3.html). He also has ‘classic’ brewing cities’ water listed there too (if you want to emulate a particular city’s water (e.g., Burton on Trent or Plzen)).
Here’s the baseline Victoria water analysis (that you’ll need for the spreadsheet):