Exploring the effects of a low mash pH

I've seen a couple of older posts here and there on this topic but nothing was really definitively concluded (from what I read). The threads also seemed to be more about "I just brewed and my mash pH was too low, should I be worried?" and less about possible unintended side effects. This isn't really a thread where "RDWHAHB" is appropriate, I'm just wondering if I should rebrew any of the batches from the past year to see if the flavors are different with a correct process.

Anyway, here's my story:

I've been brewing for about 5 years now - about a year extract, rest all grain. I have an electric HERMS system for mashing and boil with propane. I've got quite a few nice toys to pay attention to as many details throughout the process as possible. I've made a lot of great beers although not as many great ones in the past year or so.

I've struggled with mash and sparge pH for a while. My mash pH is often pretty stubbornly high, which I always attributed to our high alkalinity water. Not knowing quite enough about water, I didn't think much of it because I always thought I got good conversion (constantly hit OG and FG numbers based on Beersmith recipes).

Brewday often goes like this, so here's my transcript from my brew on Monday. I mash-in (includes 2:1 ratio of distilled water, brewing salts and ~6 oz of acidulated malt), pH reads 5.75. Add 1.5 mL of lactic acid, let circulate, pH reads 5.63. Add another 1.5 mL & circulate, pH again reads 5.63. It was after a third charge of 1.5 mL of acid I finally decided something was wrong. I may not have thought about this as much in the past because I typically brew low SRM beers, but this was a ~20 SRM strong ale and shouldn't have that type of problem. Acidifying my sparge water wasn't any better, and I couldn't get it to go below

So, I decided to dual-point calibrate my pH meter for the first time in... ever. (When I got it, I tested it in 4.0 calibration solution and it read 4.00 so I never touched it again). Post calibration, here were my readings:

Mash pH - about 4.6
Sparge water pH - about 3.8

!!!

Panic set in. I quickly convinced myself that it wouldn't be a huge deal because I've brewed literally all of my beers in the past year using a very similar process, and they were all average at worst and good at best. During the boil, I decided to finally download Bru'n Water (which I will be using everytime from now on) to double check what I was seeing. After finally learning how to use it, Bru'n Water almost exactly calculated what my newly calibrated meter was telling me.

What an idiot!

Having said that, I'm wondering what impacts this might have had on my beer in the past year. Here are some of the things I've experienced:

1. Muted whirlpool/dry hop aroma (compared to batches I had done before
2. Thin tasting beer despite appropriate FG
3. Lack of head retention

Do any of these seem like they could be caused by constantly having mash pH too low? I also thought a couple beers had a a very subtle but strange flavor which I attributed to a new yeast I hadn't used before (Super San Diego). Perhaps the yeast was not the culprit, though. Maybe it was how the yeast reacted to a higher pH of wort.

 

A few questions:

1. What is the batch size?
2. Is your sparge water distilled, tap water, or a mixture?
3. What brewing salts are you using, and in what quantities?

I was in your situation a while back, and really just got sick to death of testing and tinkering without my beer getting as good as I expected. The variability of the tap water composition made things very difficult. In the end, I just decided I wanted to enjoy brewing more than I was, and went with a clean slate of RO water for everything, and adding salts and acidulated malt to get to the desired mash pH. My sparge water is pure RO. My beer is much better for it, and I enjoy brewing a lot more. Sorry this doesn't answer your actual question, btw.

 

1. 5.5gal
2. Mixture, but probably about 75% distilled
3. The last batch was 7/7/4 grams of gypsum, calcium chloride, and Epsom salts, respectively. Edit: I should mention these were only added to the mash along with the grains. They were not added to the sparge water.

I've thought about going pure distilled water, but now that I have the appropriate tool (bru'n water) I think I can actually go the other route and eliminate distilled water completely, which will save $10-15 per batch.

 

Yep! Those are all elements that I've experienced with too low pH. Low pH does reduce hop extraction and when mash pH is too low, the wort and beer tend to come across as 'thin'.

 

Thank you. I can't tell you how much that helps me.

 

Best of luck!!

 

It's costing you $10-15 for RO water? I buy two 5 gallon jugs at the grocery store and it's right around $3. Well worth the cost to start with a known commodity (especially when you consider that the tap water profile can drift over time and, even worse, change pretty radically with the seasons).

I use Bru'n Water and started out testing ph, but it was always so close that I don't even test anymore. I can calculate everything ahead of time, have my water additions pre-measured, and just grind my acidulated malt (if needed) with the rest of the grains.

So far my results have been pretty spectacular. I'm well over 1,000 beers on untappd, I've had many of the highest rated IPAs and stouts, and the stuff I'm brewing is really good (better than the vast majority of shelf beers I can get). I love it, my wife loves it, my fellow craft beer gurus love it....that's all I need out of this hobby.

Looking forward to kegging my next NEIPA tonight....

 

If you're spending that much for RO water, you might want to get a home filter. We had been using our tap for a bit (after driving 30+ minutes to Walmart to fill up cheap RO for a while), but had inconsistent results, and decided to just spring for it. Here's the one we bought: https://www.amazon.com/gp/product/B00DOG64FM/?tag=skimlinks_replacement-20

At $15 a brew, you'll have paid it off in 5 batches, and saved yourself the trip to the store.

 

Yes, $1 per gallon "on sale" (it's always on sale) for distilled water. I'm not sure where you live, but there are no RO filling stations or anything like that here. It may be a NY thing. I may continue to buy it, but I'll probably give it a shot without the distilled for the next few batches.

 

Oh, you're buying the 1 gallon jugs of distilled water...that makes sense. My local grocery store has an RO filling station, so I fill 5 gallon jugs for about 30 cents a gallon. Bummer that you don't have that option.

 

Don't see why aroma should be effected as that's derived from essential oils but isomerization and thus bitterness are definitely reduced at low kettle pH.

I'm guessing (and I do mean guessing) that the last two are related to protein deficit. The low pH, perhaps, moved the proteins closer to isoelectric point resulting in more precipitation thereof? Was the boiling wort more egg-drop soup like than usual?