I ask this as I've historically hit my target mash pH within a point using the water calc tool on Brewersfriend.com until today brewing my 4th batch of a Guinness clone. My target mash pH for this beer was 5.2. I always build up my water from distilled water. 10 min into mash pH was 4.8! Following the advice I've read in this forum that it takes 20-30 min for the mash pH to stabilize I didn't over react. At 20 min pH was 5. At 30 min pH was 5.06. At one hour it was still 5.06. I calibrated my pH meter prior to mashing in. I rechecked calibration after my 4.8 reading and it was holding within 1 point of the calibration solutions.
Has there been a recent change to the Brewersfriend Water calc algorithm?
- Thread starter youngdh
- Start date
Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:
Hermit
fuddle
Umm... If this was your fourth batch did you change the 'water recipe'? If you always start with distilled and build up then why were you even checking the calculator and not going by what your notes told you from past experience? Did you input the exact same parameters into the calculator? Unless something changed on your end you shouldn't have even been using it.
I think the more likely culprit is a changed water supply. I doubt they've changed the program.
I changed the grain bill a bit by reducing my roasted barley and acidulated malt to reduce what I felt in the last batch was to roasty of a flavor and a bit too tart of a mouth feel.
That could be it. I used a different brand of store bought distilled water (claimed it was steam distilled on label but didn't specify if single or double distilled, so, most likely single distilled).
I plugged my numbers into Bru n' water and got similar results as Brewersfriend calculators. I would have had to double the amount of 10% Phos Acid to hit the measured pH according to Brewersfriend and Bru n' Water.
I'm beginning to wonder if my calibration solutions are off. My two bottles of 4.01 and 7.01 solutions seals were broken about 6 months ago. The expiration dates on the bottles are 5/2019. I always pour into separate containers for calibration and immediately reseal the original container so as not to contaminate them.
Hermit
fuddle
OK. You reduced two malt ingredients. What did you change in the water? I think we need some actual numbers here. If you left the water the same the pH should have been HIGHER.
Grain Bill:
Maris Otter 4.28#
Flaked Barley 1.59#
Roasted Barley 0.26#
Dehusked Carafe III 0.18#
Acidulate Malt 0.06#
To total mash water of 5.25G distilled water added following adjuncts:
Baking Soda 1g
Gypsum 1g
CaCl 0.75g
10% Phos Acid 30 ml (added prior to heating mash water)
Target pH 5.2
Target water profile (Wicklow Mtns of Ireland):
Ca:18, Mg:2, Na:13, SO4:22, Cl:20, HCO3:35
Target volume into fermenter is 2.9G
Hermit
fuddle
I asked for the differences between the two. But the obvious thing is that you use acid malt and phosphoric acid to lower the pH and then use baking soda to bring it back up?
I'd stick to the phosphoric acid to adjust the pH, then you only have to worry about one parameter.
The acidulated malt was in lieu of soured beer to get that Guinness "twang" and not to manage pH. I did this for my previous batch of Guinness clone and had to much twang so I reduced it from 1.25% of grain bill to 1%. Same for the roasted barley to cut back on to much "roast" which I reduced from 5.1% to 4.1% of grain bill. This is what required new water calcs. I used the baking soda and other minerals to get close to my target water profile (Wicklow Mtns, Ireland) first. The Phos Acid, which has a neutral flavor impact at low concentrations, was then used to bring the calculated target pH back down to 5.2. Without the Phos Acid Brewersfriend calculated a mash pH of 5.6.
I went back and looked at my numbers from my last batch of this recipe back in May where mineral/salt amounts were the same but called for 38 ml of Phos Acid. My mash T-30 pH measurement was 5.00, so, for past 2 batches of this clone I've undershot my mash pH by 2 points. The fact that both Brewersfriend and Bru n' water were in agreement on the numbers I'm now beginning to suspect my pH meter (Milwaukee MW102). I calibrated it just before making my measurements, but, might not have been at correct calibration if my calibration solutions are possibly shifting. The 4.01 and 7.01 solutions came from bottles I unsealed about 6 months ago. I'll defer to the experts in this forum to say if calibration solutions can shift once exposed to air even if bottles are tightly sealed and not exposed to light/sunlight while in storage. Net, net, something is consistently off by 2 points from target pH.
Hermit
fuddle
Calculators are starting points ONLY. Malts are too variable to make these calculators that precise. That is why it is recommended to do a small scale mash to get the 'real' number or simply use your old numbers as a guide. You are best to stick to one recipe and do ONE change per mash if you want to do it this way.
So if malts are truly that variable, and I get it that they are, we must either adjust the pH realtime if pH being right on target is important to the mash/style of beer or accept that if pH is off by a couple of points so be it as the same recipe with no changes will vary batch to batch irrespective of the calculators anyway. Honestly, given the past 2 variants of this Guinness clone 4 months apart have both undershot pH by 2 points has me looking at my pH meter and calibration/calibration references. Thanks everyone for the dialog on this 
.
.
