Using Rain Water For All Grain Brewing Is It Ok?

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Hey guys my name is steve I'm a new starter with all grain brewing have brewed with kits before just using ordinary tap water now I am almost setup for all grain brewing with the typical three vessel setup a boiling drum a mash tun and a hopping vessel and also a herms coil , I was just wondering if it would be ok to use rain water ? My tank is a plastic food grade run of the mill water tank from tank master ? I have heard water with a high acid ph reading still can be used for stout I was wondering if rain water could be used for brewing all beers? Do I need to treat rainwater ?Water chemistry is a pretty heavy subject !
Any feed back would be greatly appreciated
Kind regards steve
some say you have to treat the water before you use it, though I would be happy just filtering it for larger nasties then boiling it should kill the rest

I use tank water, but as I brew AG it all gets boiled before it hits the fermenter.

I use the BeerSmith water tool to adjust my water as needed with brewing salts etc.

There's a free calculator to allow you to do that, and it has a lot of support on this forum:
Only have tank water at my place, works well. I have a 10 micron filter the services the whole house and a carbon filter for the kitchen ( brew water from here). If your tank is clean all should be good. Make sure overflow is screened otherwise all sorts of things get into tanks.
I have a tds meter to check water content, can get them pretty cheap. My water is typically under 10ppm tds. The next step is a pH meter and do some reading. If your water is low in minerals then will make excellent light coloured beers.
Most probably your water will be low in calcium, which is important to mash chemistry. Typically I add CaCl and Ca SO4 ( gypsum) for calcium and pH control ( as well as acid malt if required). For dark grains( which lower pH) I typically steep separately the dark grains and add to the boil as I don't want to add carbonates to my beer.
However to begin with just try some brews with the rainwater and get used to your system, when you get a bit of practice then start on the water side of things, as imo they just "fine tune" your beer.
rain water is fine but i would look at maybe some pH strips most home brew shops sell them can be a good way to check mash pH. i also like to be able to adjust the water depending on style. things to remembe for additions is calcium sulphate for hoppy beers calcium carbonate for stouts and calcium chloride is good to add calcium. beersmith is amazing and well worth it. bottom line though no you don't need to but i think you will make better beer. as pH goes carbonate raises and sulphate and chloride lower. i find with lighter beers i needed to add minerals to help lower pH to avoid astringency. otherwise welcome to all grain
I agree, rain water can be a great source of water, and can really stand out when you make lighter beers, like pilsners.

Taste it, does it taste clean and nice almost sweet? Then awesome.

IMHO if you want to use rain water you need to get into water chemistry. That spreadsheet as linked above is a great resource. I've also got some notes on my website, from when I researched about it. Spend the time reading the resources out there, it's not rocket science but can may a good improvement in the beer.

Unfiltered tank water here.
Occasionally even some leaf debris and tannins if heavy rain stirs the tanks.
Maby a teaspoon of chalk in dark beers.
No worries.
I use straight tank water for pilsners and lagers,( mind you no industry around to put too much shit in) I add 1/2 teaspoon of calcium chloride to the mash, dont know if it makes any difference,
putting down a dry lager tomorrow might try without the calcium and see.

For ales and stouts I use tap water, no idea on the chemistry but it works fine for me.
I use straight tank water as not on town water.... I have done about 10 AGs now and haven't even begun to think about water chem yet... Still working out the other stuff... I still have a list of things that I need to improve to get the beer I want and I feel water chem is down the list.

Make great beers as it is but will be keen to one day see what difference water chem makes to my beer :icon_cheers:

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