Questions on Adjusting pH Up Post-Fermentation

Your mash pH, boil pH, and post-fermentation pH will all be different. As long as you get good starch conversion in your mashtun, I can't think of a reason why you'd want to alter it post-fermentation.

No differences in water, btw?

 

Some carbonates would be advisable to add to your mash to raise ph a bit (5.4-5.5) and to round flavor a bit too. I would add about 4 grs of CaCO(calcium Carbonate) for 5 gals of beer

 

To the mash

 

You could increase the pH of the finished beer by adding some more slaked lime or some baking soda, but why do you want to? Does it taste tart? What's the current pH?

 

Base malts can have different resulting pH, due to lovibond differences. I had a bag from a lot of Best Pils that was contaminated with acidulated Malt, that came out about 0.25 lowered than expected.

If I was not so lazy I would measure out a small sample of the grist the night before, mash it with my treated RO water, and determine if the pH matches the prediction.

You can adjust the finished beer. Go slow with additions, as you can't take them out, and it is just more work to have to go back the other way.

 

Hmm...I just can't imagine that two MOs would swing that far...

Yeast will be a big player in final pH of the beer. I would definitely hold off before making any changes. I often prefer a more sour-sided stout personally (think Guiness FES)....especially to counter the sweetness you're going to have in a sweet stout.

 

I have noticed a difference in taste between crisp and Simpsons marris otter. Never measured the pH.

 

The thing to remember about Maris Otter is that the name actually refers to the variety of barley, which can be kilned to whatever degree the maltster wants. So some are darker (more highly kilned) than others. IIRC, someone even makes a Maris Otter derived malt that's is extremely low kilned, like a pilsner malt.

If you try a new Maris Otter malt and it gives a much lower pH than you're used too, it's probably more highly kilned than a typical Simpsons/Crisp/Fawcett M.O.

@scurvy311 do you happen to know the Lovibond rating of the M.O. you used? Since you're using BrewCipher, you could change the Lovibond on the M.O. row on the Malt tab, or add a new row on the malt tab for this particular M.O.

That said, color isn't the end of the story. Sometimes you just have to dial in by trial and error when using a grain that doesn't behave as expected.

 

Below is color data from the MoreBeer website:

Bairds Maris Otter Pale Ale Malt: 2.5 – 3.5 °L

Thomas Fawcett Maris Otter Pale Ale Malt: 2.3 – 3.0 °L

UK Gleneagles Maris Otter - Crisp Malting: 3.8 °L

So, the Gleneagles version is the darkest and it would be reasonable to expect it will acidify the mash (i.e., lower mash pH value) more than the other versions.

Cheers!

 

This definitely varies by lot as well. The most recent bag of the Gleneagles I just used up was 4.5L, and the bag I just bought is 4.0L. Also, of note it's not called Gleneagles anymore, it's No. 19.

 

The magnitude of the pH difference is surprising to me. Attribution of that to the couple degees Lovibond in the kilning of the Glen Eagle MO seems like a stretch. I think there is probably enough batch to batch variation in kilning that we would see this kind of problem more frequently than we do, if a couple L made a big diff.

My initial reaction was that maybe you were supplied a different malt than you think, sort of like @hopfenunmalz experience with accidentally getting acid malt. The other thought was you mismeasured your chemical additions. For example, maybe the slaked lime has absorbed some water and your mass represents a lower amount of lime than you think. I don't know how hygroscopic slaked lime is, off-hand. Picking on that one because I think it is the one where a small mistake could lead to the largest impact. Just speculation.

 

If anything, 4.7 is a little on the high side for a finished beer. I would definitely not try to increase it.