A brewing friend is making his first steps into the murky world of water chemistry and treatment. This got me thinking about what I do and information I've picked up in the last year or so of brewing.
So here are some of my tips to help with this dark side of homebrew.
1] Don't worry too much about the detail. Seriously don't! Unless you have a perverse interest in the complicated chemistry then just learn the basics. There are plenty of resources and calculators on the interweb to help out.
2] Don't try to eradicate the alkalinity completely. You want some residual alkalinity remaining. The amount will depend largely on beer style - or more accurately the malt / colour profile. Darker malts have higher acidity and will remive some of the buffering effect of the alkalinity. Lager < 20, bitter 30-50, Stout / porter 100+ as a guide.
3] Don't worry if it's not spot on straight away. Although based in science there are many factors that affect the end result. These might be recipe or even equipment related. The important thing is to keep tweaking and measuring. You won't be far off.
4] Treat the brewing liquer in bulk and then run with it. Once it's mashing it's too late to make any changes. By all means take the ph measurement at the start of the mash but trying to correct something now will be hard to do and likely to get things worse. Record everything and then tweak next time.
5] Only treat the mash with calcium additions and for alkalinity. Other additions are best added to the boil only as they are detrimental to the processes in the mash.
6] The flavour profile can be changed by tweaking the sulphate / chloride ratio using Gypsum (calcium sulphate) and Calcium Chloride. More sulphate will accentuate hop flavour and bitterness, more chloride will accentuate the malt.
7] Don't be afraid to use common salt in darker beers. Don't over do it - only very small amounts are ever required but as in cooking it can enhance the flavours of the beer being produced.