Rainwater harvesting

FirebladeAdam · May 25, 2021

Has anyone tried brewing with rainwater?! I'm doing it now for the first time... I've got a Hefewiezen on the go, it's just carbing up. I figured it might have fewer chemical elements to it, maybe less flouride/ chlorine and other things.
Is this pointless? I've done no research!
Interesting factoids to contribute anyone?

Davy6Mac · May 25, 2021

Just a quick question did you run the rainwater through a filter system before using?

cushyno · May 25, 2021

I have harvested rainwater. I made sure the rain had been tipping down for 30 minutes to wash any dust and debris off the roof first. I collected 15L of rainwater through a fine mesh bag as a filter. The water was added to 15L of my hard tap water. The rainwater significantly reduced the overall hardness but I had to add back some calcium in the form of calcium chloride.

It made a fairly decent Munich Helles.

I'd harvest rainwater again if the timing was right. You need to use it within a day or so as it doesn't keep.

I figured that filtering through the mash and boiling for 60 minutes would be enough to remove/kill any airborne nasties.

foxy · May 25, 2021

FirebladeAdam said:
Has anyone tried brewing with rainwater?! I'm doing it now for the first time... I've got a Hefewiezen on the go, it's just carbing up. I figured it might have fewer chemical elements to it, maybe less flouride/ chlorine and other things.
Is this pointless? I've done no research!
Interesting factoids to contribute anyone?

Loads of people brew with rain water over here, they have no choice as they won't be connected to any water supply, just tank water, then it depends on what tank they have there are still concrete tanks so that will alter the profile.

FirebladeAdam · May 25, 2021

Davy6mac; not exactly filtered, but off the roof after a while runs clean, I can see there are no bits in it and although this doesn't account for tiny particulate I did boil it before I used it, I used it the next day and in terms of filtering, after mash/flocculation/cold crash there's not a lot still going to be in suspension. And no bacterial stuff unless it survives 101C. It certainly smelt less chemical compoundy than tap water anyway... Although because I live near a filter station the water company put a huge filter in my house and change it every 4 months I think.
I drank some out of the fermenter before I bottled and it tasted great but it always does! I've never made a bad hefewiezen but one went very sour once, don't know why but it was an interesting beer for it, and I wish I could replicate it!