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Jun 08, 2022 View:

Anyone using RO water for mashing

I recently switched to RO water in my house. I was considering using it for my mashing but wasnt sure if I would run into any issues using enzymes etc by using it. These are the enzymes I am referring to if it helps. There really wasnt any info on them other than a video how to use them. They have always worked great with my tap water. TIA


RO won't have any significant buffering ability so you'll really need to watch your pH. Also, some calcium is recommended for stabilization of seb enzymes. Don't forget your yeast will need nutrients too, calcium also being a critical component. 


Some brewing books talk about using RO or other purified water for brewing. You just have to make up for the lack of minerals. Look up burtonizing.


How does your water test before RO?  Are you sure you even need to?  Your water could be ideal.  RO with chemical additions could be completely counterproductive.

Personally, I'd be more concerned with removing chlorine, chloramines, and VOCs, if they are a problem, of course.




For mashing with distilled spirits there isn't really a need to use RO - just use carbon and UV to filter the water, or carbon at the least.  

As for the enzymes, at 3d0g pointed out, your issue will be with pH crashing due to the lack of buffering capacity.  This will likely make your enzymes unusable.  When I was making whiskey (doing rum now) we used STAR and distillers barley (higher protein so beer guys don't like it, but higher diastic power so we can use less).  It's easy to use just follow the instructions (1oz per 100 gallon i think?) and stay within temp/pH ranges.  Remember, the temp stated is the highest temp that it'll work at - the enzymes will denature over 150F+ (i don't remember on this particular brand) so add after you've boiled your corn. 

But basically, be sure that you really need to use RO for mashing if you go down that road.  Pick up Water by John Palmer.  You can skip the middle chapters for the most part but for <$20 it's worth picking up a copy. 

Reply:2 minutes ago, nabtastic said:

I think you might have missed the "I don't remember on this particular brand" comment.  I was saying to read and follow the directions for the brand he has purchased (as the parameters vary by supplier).  It's been a few years since I've used SebStar and don't recall their instructions.  I do know that they sent me every bit of information I requested when I asked for it  3+ years ago.  Enzymes will work up to XX temperature, but that doesn't mean they need to be at the temperature, meaning they will also work at lower temperatures if it's relevant to the OP's particular process.  

Regardless, OP was asking about using RO water for mashing.  Since you make whiskey, maybe you have advice on that? 

Reply:12 minutes ago, nabtastic said:

no no, just salty because I haven't finished coffee yet   (still morning over here)

but I am interested in the RO v carbon water for distillation.  When brewing RO makes since because the ion content can significantly alter the finished product and you want consistency between brewhouses.  I have no experience in whether or not this carries into distillation and was hoping you (or others) do

Reply:2 hours ago, nabtastic said: