@Phoenix Ale : You’ve opened up a pandora’s box but let me see if I can help a little bit.
I started using bottled water (which is great quality) but I didn’t like the amount of plastic I was wasting. So I switched to tap water. 24 hours before a brew, I treat the total amount of water that I’m going to use with a campden tablet to get rid of any chlorine etc.
I did try to get the Dublin water profile for my area from water.ie but they only had daily quality reports. But I then found a old post on the Irish brewing forum (which has very little activity) that outlined the profile for the Stillorgan reservoir which is where my water comes from and the ph is 7.5.
When you add the grains to the water for your brew, it reduces the ph level but you really want to hit a certain target ph range depending on the beer. IPA’s are around 5.2 but stouts are usually higher (say 5.5). I used to use a ph meter but I don’t really bother with it anymore.
But I do use the Brewfather app which is great for my recipes and it works out the water profile for each one. With the water from Stillorgan, I always find that I need to add 5ml of lactic acid to the mash to get back into the right range for the ph level for a particular beer style.
Here’s the profile I use for Dublin in the Brewfather app:
Water chemistry can get a bit complicated but Brewfather also can help you to add the right levels of sodium, calcium chloride etc for a particular beer style. I use gypsum, calcium chloride, edible epsom salt and standard bicarbonate to adjust the water accordingly.
But to keep things simple in the first instance, just treat your water with a camden tablet and maybe buy some 80% lactic acid from a brew shop and add 5ml of it during the mash.
However, I highly recommend the paid version of the Brewfather app (which is very cheap and you you can use on it on a PC and phone at the same time). It can seem a bit complex at first but you’ll soon get the hang of it.
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