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Rain Water

Does anyone have experience brewing with rain water? I can not find any info?

No experience, but that’s because after thinking about it I decided that I really didn’t want to. I just don’t feel it’s safe.

I’ve heard rainwater can pick up a lot of contaminates while in the atmosphere. dont wanna get into global warming, but there is a lot of nasty stuff floating around.

keep in mind, this is all hear-say

Rain water is naturally soft and I have friends who collect it for use as their only source of water for their entire house - they have lined tanks and use a fairly complex treatment system (but no chemicals like chlorine). You can certainly use it for brewing, but you’ll need to figure out how to collect and use it in a safe manner.

Most cases rain water is collected for non-potable water needs. Rainwater is typically perfect for a base brewing water and is usually very close to RO in chemical makeup. But at the very least to make rainwater potable it would need sand/ other filtration for gross debris and then treated with chlorine, ozone or UV light to address the main concern of biological contaminants. Outside of this the other concern then is toxins picked up in the air, in looking at one study it was stated that the rainwater tested showed double the amount of toxins compared with surface water in the same area. So if going this route it would be best to gross filter, treat for biological contaminants the same as you would a well source and then use a 4-5 filter RO systems that strips just about all of the toxins from the water.

To find info across the web, just google some combination of potable + rainwater etc… and there is plenty to see.

Wow, that’s pretty neat!

A friend of mine collects rainwater for use in washing. He has two spigots, one for county water and one for the collected water. If you have a metal roof that would be better than shingles as far as contamination.

It really depends on the type of metal roofing. Galvanized roofs will push up the zinc concentration in the water to potentially toxic levels for yeast. And if the zinc layer is gone, then the iron level might be increased. An asphalt shingle roof might give up some hydrocarbons into the water. The best option would probably be anodized aluminum. Its the most inert.

I know it’s a late response but I just noticed this post. I lived in Hawaii, on the big island, for beaucoupe years and a huge percentage of the people there have only rainwater because you can’t dig a well in solid lava rock(I guess.). Anyway, we all used doughboy pools to collect rainwater(5000 gallons). Birds fly over and leaves blow in etc., but none of us ever had any problems from drinking it. I just had a little filter between the pool and the house. I also know that people in Bermuda have been doing this forever. They built the cisterns under the house and collect it there.

Yeah, no fresh water source in Bermuda, so they collect rainwater. Their roofs are specially made to filter the rainwater, which then flows down into holding tanks below the houses. If you drive around the island, you can see roofs in various states of disrepair, and iirc, it’s a result of the increasing acidity of rainwater.

If you’re going to do this, I’d strongly recommend collecting rain water throughout the year and find a way to get it tested for various contaminants. In particular, if you’re near a coal-fired power plant, or if you’re downwind of one, get your water tested for mercury.

Thanks for all the great info. I think I will stick to RO and spring water.

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