Refractometer adjust

Arbe0 · Dec 30, 2016

DArn it I just noticed that I put refractometer rather than PH meter...sorry

Just adjusted my PH meter (buffer solution 7.01 and 4.01). After I got it all adjusted (to 7 and 4) I thought it would be nice to check my tap water.
The Tap water PH was 6.8, but I had Ward labs test it last year and it showed 8.3 PH and the City water report from 2015 showed 7.11 to 8.03 that is a big difference. ????
so when I use the Brun water calculator or Ez water report do you think I should use the one from my PH meter? And is there a chance I did something wrong in checking with my PH meter?

dmtaylor · Dec 31, 2016

I think I know what is going on...... Water from your tap contains dissolved CO2 gas which tends to reduce the pH when fresh. By the time Ward Labs receives it, the CO2 gas is escaped, raising the pH in their value. So.....

If you are mashing with fresh warm water from your tap, then use the lower value (about 7). But if you are mashing with water that has been pre-boiled to deaerate or to remove chlorine, then the pH will probably be up at the higher value of 8.0-8.3.

Arbe0 · Dec 31, 2016

I normally use a Pur water filter and leave the water in an open container over night then add a campton tablet to the mash tun. I haven't used RO water yet so the water is from my kitchen faucet.

dmtaylor · Dec 31, 2016

In doing that, you are deaerating your water. As such, I expect your brewing water would be closer to a pH of about 8. It will only be 7 if you measure it immediately straight out of the Pur filter.

DurtyChemist · Dec 31, 2016

I'd go with your pH meter then check your mash pH and see how accurate you calculations are compared to actual results. If you measure the water pH to be 6.8 put that into Bru then adjust the mash and see where you're at. I'd expect you to be pretty accurate and the City results of 7.1-8.0 are pretty broad and probably cover two samples they took.

Arbe0 · Dec 31, 2016

sooo.. I am gonna use the PH meter to check the water ( normally let it set over night ) as I put into the hot liquor tank before I heat the water up should work good with the Brun water calculator, then about 15 minutes into the mash tun to see if I hit the target PH.
Does this sound right?