RO Water

[John Holgreaves]

Hi,

I bought a RO filter and have used it a couple of times.
I thought that I had read that it was only necessary to use RO water in the mash water.
But while setting up my brew this morning I thought this is probably wrong and I should filter the sparge water as well as the mash water.

Thanks for any information on the subject.

Regards John

 

[The Baron]

I guess you are using RO water so that you can make your own water profiles in that case treat all your water used whether it be mash or sparge the same

 

[chthon]

You have to add minerals also to your RO water, at least CaCl and CaSO4 (calciumchloride and calciumsulphate), and you better add some yeast nutrients in the boil.

 

[John Holgreaves]

Oh thanks Baron. That's where I have been going wrong.

Filtering the Mash water and adding the salts in to the mash for the whole brew and not filtering the the sparge water I am getting salts overdose.

I now need a 70 litre bucket to filter the water for the whole brew!

 

[chillipickle]

I used to use this sort of jerry can when i was making ro water for the fish tanks.Lifting 70ltrs ouch.

https://www.ebay.co.uk/p/11037775590?iid=184512927092

 

[John Holgreaves]

It wiil be mounted on the wall and gravity will do all the hard work.

 

[Cheyne_brewer]

I just got a very cheap 3 stage RO kit for occaisional brew use.

Looking at the water profile for Pilsen, this is almost devoid of minerals. Would it be sensible to use straight RO water for a Pilsener lager (clarity issues aside) or maybe use 80% RO 20% treated tap water (moderately hard). I don't have a full water report. I'll stick with my treated tap water for ale styles as it produces good results.

 

[JockyBrewer]

Best thing is to use RO water to dilute straight tap water down to your desired level of alkalinity in order to achieve the right mash pH.

You can then add calcium chloride and calcium sulphate in the boil to adjust the final profile.

 

[Benfleet Brewery]

Best thing is to use RO water to dilute straight tap water down to your desired level of alkalinity in order to achieve the right mash pH.

You can then add calcium chloride and calcium sulphate in the boil to adjust the final profile.

I just bought a cheap 3 stage RO filter too. I was thinking I’d dilute my tap water to achieve my target sulphate and chloride then use lactic acid to get the mash PH from there to where I need it. is this not a good way to do it?

 

[JockyBrewer]

I just bought a cheap 3 stage RO filter too. I was thinking I’d dilute my tap water to achieve my target sulphate and chloride then use lactic acid to get the mash PH from there to where I need it. is this not a good way to do it?

It depends what your starting point is, but yes you can go that way.

 

[Benfleet Brewery]

It depends what your starting point is, but yes you can go that way.

I was adding about 2.8ml per litre lactic to my water for light beers and wanted to bring that down a bit. At the same time, I don’t want to be using RO to take stuff out only to have to add it again (thinking of my water bill)

 

[JockyBrewer]

I was adding about 2.8ml per litre lactic to my water for light beers and wanted to bring that down a bit. At the same time, I don’t want to be using RO to take stuff out only to have to add it again (thinking of my water bill)

I'm not particularly keen on using lactic acid so minimising that is good, and if you can achieve your desired profile this way they go for it.

The main issue I have is where people start with RO as an entirely blank slate and then try to add alkalinity (carbonate/bicarbonate) back in using chalk or sodium bicarbonate. It's something I'd only consider if I was living in a part of the world with poor drinking water quality.