URGENT! Mash pH shifting with temperature?

Ok so background...

100%pils mash ( wyermann floor malted bo pils)
100% RO with 3ppm TDS 4g gypsum, 2.8g cacl, 5.6ML acid shooting for a mash pH of 5.3

Milwaukee MW102, and all samples taken at 21c

dough in 103f first check 5.45, added 1.5ml second check 5.25

130 rest 5.45

149 rest 5.70

All rests RAMP with HERMS no infusions.

I am confused as to why it is raising like this? Does the water not have enough to buffer? Have other seen this?

 

ok?

 

Sorry it hit post before I finished!

 

It is possible that the higher temperature is leading to a down stream effect (reaction or higher solubility) increasing -OH concentration. The thing is though that for what I know about mash chemistry higher temp actually favors an increase in H+ concentration so if anything as the temp rises your mash PH should be decreasing. Anyway I don't think it is a big deal as long as you dial the PH in once your saccharification starts.

 

what temp is the sample?

 

From the first post.

 

Mash pH shifts with time and temperature. The lower the temperature the higher the pH. Typical shift from 50 to 20 °C might be 0.15 pH. If acid has been added pH will rise with time too as the acid is absorbed and neutralized by the malt. If base has been added quite the opposite but for the same reason. As it is consumed over time the pH drops. So shift is normal but not by so much as you are reporting. Check the stability of your meter (see pH Cal sticky).

 

More details...

Grist:
100% Wyermann Floor malted Bo Pils
Water :
100% RO 3ppm TDS
4.6 grams Gypsum
2.8 grams CACL
5.6ml Lactic Brunwater predicted mash ph of 5.3
Mash
dough in 103F (15 minutes)
Protein rest 130/20 (20 minutes)
Beta rest 149/40 (40 minutes)
Alpha rest 156/30 (30 minutes)
Mash out 169/10 (15 minutes)
All rests step mashed with a HERMS, no infusions.
I scrapped the first mash after WILD pH readings and now am on mash #2 but for data purposes I will list them 1 and 2
All readings taken with a Milwaukee Mw102(verified with my other not so precise meter as well) with samples as close to 20c as possible.
Dough in:
1. 5.45, then added 1.5ml to get lower hit 5.25 (total 7.1ml lactic, lactic added to mash, was tired and forgot to add to water)
2. 5.15, with initial 5.6ml ( this was added to mash water then heated, like normal.)
Protein Rest:
1. 5.45
2. 5.56
Beta Rest:
1. 5.7 (added 3ml of lactic, 10.1 total)
2. 5.72
Alpha rest:
1. 5.5, but then scrapped the project, wort was off tasting and very cloudy
2. 6.02
Mash Out:
1. didn't make it ( though should have)
2, 5.66 ( YES YOU read that right)
Preboil:
Target 7.7 gallon at 9 brix at 5.3 pH
Actual 8.4 gallon at 10.1 brix at 5.55ph ( YES you read that right again)
So pH was actually falling on its own.
Boil ph (10 minutes in)
5.74
Added 3ml lactic, 5.37 Boil pH for first hop addition.
Post boil: 5.10
OG:1.052 ( was supposed to be 1.048)

 

crickets huh....

 

did you perform a stability check on your meter as aj recommended?