Yet another mash pH and efficiency question/problem

[peanasky]

I brewed a NE-IPA last night. I build from RO, and Bru'n water expected a mash pH of 5.44, I got 5.74! As a result my efficiency dropped from my usual 80% to 75%, I also collected more water than expected (which is weird).

Below are screen-caps of my grain bill, adjustment, and target profile:



Additional info:
pH meter is a Thermoworks 8689, calibrated 12 days prior to brew day at 7pH and 4pH.
I brew 3 gallon, BIAB batches with a "dunk" sparge.
Mash temp started at 151F, ended at 149F.
RO water base measured 2ppm with my TDS meter (measures 180+ on my tap water)

Any thoughts? I should've just added some acid and called it done, but I'm just a bit confused since my first to batches adjusting water worked out so well.

 

[bitteritdown]

I think your grain Lovibond colors are off, though I don't know how big a difference that would make.

2 Row = 1.8
Wheat Malt = 2
Flaked Oats = 1 (unless you're toasting them?)

Also maybe Bru N water expects the CaCL and CaSO4 to drop pH more than they actually do?

Have you tried comparing with a different calculator?

Don't know that the efficiency can be entirely blamed on the pH though, also look at crush, squeezing, etc...

 

[peanasky]

Yeah, those colors were "in the neighborhood" kind of estimates. I increased the color on them, but that just gives me a lower pH.

Interesting thought on the chemicals. My two previous beers were fine, but with this one, if I take out all the additions, I have a mash pH of 5.75, which is almost exactly what I had. Weird. And yes, I did remember to add the chemicals!

Efficiency is weird for me. I need to check my crush again, although it looked good coming out of the mill. I did get more volume into the kettle than expected (4gal vs 3.75gal), but I boiled down to 3gal, so that shouldn't affect it too much.

I'm almost tempted to say it was the oats that I used. I used "old fashioned" Quaker oats.

 

[bitteritdown]

Yeah, those colors were "in the neighborhood" kind of estimates. I increased the color on them, but that just gives me a lower pH.

In a Lovibond based calculator that could be a problem. Telling it higher lovibond values than what really is being used tricks it into giving you a lower pH estimate when in reality you'll get a higher pH due to the lighter colored grains.

 

[ajdelange]

Sometimes the spreadsheet models fit the grains actually being used and sometimes they don't (but given such a large discrepancy here don't rule out data entry error). You should only use spreadsheets for general guidance. Always make a test mash. Eventually you will gain enough experience but until you do, rely on the test mashes.

 

[Horseflesh]

I would also write down the L ratings at the store. Malt can vary batch to batch sometimes, and hopefully your LHBS is putting values from the grain sacks on their signs.

 

[peanasky]

I would also write down the L ratings at the store. Malt can vary batch to batch sometimes, and hopefully your LHBS is putting values from the grain sacks on their signs.

Ha! You have a lot of faith in my LHBS. The 2-row came from my own bag, and the oats were oatmeal (what I had on hand). But the point stands on the wheat malt.

 

[Silver_Is_Money]

Wheat malt can have a DI_Mash pH that is at or slightly above 6. Well above most barley base malts.

 

[Silver_Is_Money]

This study seems to indicate that oats are also to be reckoned at about a DI_Mash pH of 6.

http://onlinelibrary.wiley.com/doi/10.1002/jib.178/epdf

The bottom line is that the high mash pH contribution of wheat and oats must be compensated for by some means, but some mash pH programs do not provide for any means whereby to apply such compensation.

 

[Yooper]

Don't forget that your calibrated meter, if calibrated 12 days before and not right before brewing, is likely to be off.

 

[peanasky]

This study seems to indicate that oats are also to be reckoned at about a DI_Mash pH of 6.

http://onlinelibrary.wiley.com/doi/10.1002/jib.178/epdf

The bottom line is that the high mash pH contribution of wheat and oats must be compensated for by some means, but some mash pH programs do not provide for any means whereby to apply such compensation.

Good point. Didn't know that about oats and wheat. Any thoughts on how to compensate? Maybe put in some "false" alkaline?

Don't forget that your calibrated meter, if calibrated 12 days before and not right before brewing, is likely to be off.

True. Could be just that.

 

[Silver_Is_Money]

Good point. Didn't know that about oats and wheat. Any thoughts on how to compensate?

You could consider using software that accounts for these adjuncts.

 

[mabrungard]

Considering how old the OP is, many will know that the supporters version of Bru’n Water was updated with a non-barley setting that better accounts for their higher pH.