rain water

Ok guys, humor me.

I've been toying with the notion to brew with rain water. Now, I know water profiles in rain can vary immensely based on location, but assuming you can boil out most impurities and test pH and composition of the water... Is it reasonable to consider brewing with it?

Additionally, would boiling and (possibly) filtering the water pretty much defeat the purpose of brewing with rain water? In other words, if you are bringing the rain water to tap water standards, would it be pointless to collect the rain water?

Anyways, thanks for the input!

Unless your tapwater is really, really gnarly, it seems like the main point of brewing with rainwater is being able to say to your buddies "you like that? it's brewed with rainwater!"

Boiling and filtering will not diminish this property of rainwater at all.

feinbera said:

Unless your tapwater is really, really gnarly, it seems like the main point of brewing with rainwater is being able to say to your buddies "you like that? it's brewed with rainwater!"

Boiling and filtering will not diminish this property of rainwater at all.

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True. I guess what I'm getting at is the overall safety of the rain water to drink and how it would affect fermentation.

Unless there is a huge pollution problem that shows up in your rainwater, it will be as safe as tap water to brew and drink after boiling and general sanitation practices. That 60 minute boil kills every biological entity, so the only issue is whether there is a chemical poison, which is very rare in rain water. Surface water might have a problem, but not rain.

I live in Hawaii in an area with no county water so brew with rain water. Our household water is supplied by catchment tanks (10K gal) that are filled from the rain gutters. Going to the house the water is filtered and runs through a UV sterilization tube so is potable at the tap. Haven't noticed any issues. I also haven't had the chance to get the water profiled yet but plan on it sometime soon.

Just be careful how you catch the rain water. If you are using a shingle roof, there can be chemicals leached from the shingles in the water and mold/algae from the roof surface if you live in a particularly wet area. Metal roofs are better, I would filter it personally.

If you are interested here is a publication from U of HI extension about collecting rainwater. http://www.ctahr.hawaii.edu/hawaiirain/guidelines.html

kona_dude said:

If you are interested here is a publication from U of HI extension about collecting rainwater. http://www.ctahr.hawaii.edu/hawaiirain/guidelines.html

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Great link. Might have to get a copy of this. Thanks!