Las Vegas Water

[cathlabrob]

Hi all, I have been making beer (extract and mini mash) with reverse osmosis water for about 10 years with good results. I just finished reading Brad Smiths Beer making book before I plunge into an all grain setup. He talked about water profiles and the importance for proper mashing.
I live in Las Vegas where the water is very hard, thus why I use an RO system. My question: Does reverse osmosis water contain any minerals or is it like distilled water? According to my reading, you have to add additives to adjust the water used to make it the proper pH for mashing. My RO water pH is 6.8. Does RO water contain any calcium, sulfate, chloride, or magnesiu or would I have to make water adjustments before attempting an all grain brew. I have BeerSmith software but don’t know if RO water is similar enough to distilled as a starting point.
Thanks in advance for any advice since I’m not a chemist.
Rob

 

[Jtvann]

If RO is working perfectly as it should, you’ll get zero water. Things hardly ever work as they should. I lived in Death Valley and had water with about 350 ppm dissolved solids. I had an in home RO system and had near zero or single digit TDS. When it gets that low you can just treat it as zero. Close is close enough, but you have to define your own tolerance threshold.

 

[cathlabrob]

Thank you for the information. Now I have a starting place and will use distilled as my water profile in BeerSmith. It will be close enough for me for making beer. I’m also gonna try using the software to make some small different batches of water for making pizza (‘Chicago & NY) to see if there is any difference in the dough...lol

 

[IslandLizard]

My RO water pH is 6.8.

In RO (or distilled) water pH means very little or nothing because there's no or very, very little buffering capacity in that water.

Use a (cheap) TDS meter so you know your dissolved solids, that's a much better guide on how well your RO membrane is working. If under 10 (even under 20) TDS, you can ignore the minerals, and consider it a blank slate.