So WHEN exactly is pH?

[hardrain]

Hey all, so I'm doing things the hard way, on purpose for some reason. I have what I guess is incredibly alcaline well water with a relatively high ph. I've not yet gotten a proper water test to know the actual levels.

I've mostly brewered dark beers because I knew this, but got some gypsum and a ph meter and have been playing around to see if I could brew a light beer.

I'm making a saison with mostly pils and some flaked wheat, so no acid malts. I added 32 grams of gypsum (I have no idea but this seems like a ton) on a very rough hunch from Palmer's ph charts.

Here are my readings (all at ~150F):

5 minutes after mash in, in tun: 6.00
60 minutes after mash in, in tun: 5.84
5 minutes later -- the first gallon of drawn wort, in kettle (so no grain): 5.60

I noticed a similar lowering in my prior batch I did this with. So when I'm shooting for, say, 5.6, when exactly do I want the 5.6?

 

[Jim311]

Does your Ph meter adjust for temperature? Are your numbers adjusted for temperature? That Ph seems high.

 

[Qhrumphf]

What's the batch size? For a 5 gallon batch, that's an ASTRONOMICAL amount of gypsum. I don't know if that'd be palatable, and possibly even unsafe.

Also that pH is very high. I am for 5.35-5.4 for most beers (some beers higher or lower than that though) at the very beginning of my mash (as soon as everything is corporated and consistent I pull a sample and cool), but that's at ROOM TEMP and usually no more than 5 minutes into my mash starting, which means at your temp, you're looking at ~0.2-0.3 lower than that. With that much gypsum added, either your starting water is STUPIDLY alkaline and you should be staring with RO, or you're not checking the pH correctly (meter calibration is a likely issue).

 

[MagicMatt]

I believe the pH should stabilize within 20 minutes of the mash, and shouldn't really change after that (until you start sparging).

32 grams of gypsum is likely way, way too much for a 5 gallon batch. I've "Burtonized" a couple of beers to the 250-300ppm SO4 region, and the most gypsum I've ever added was about 10g.

 

[TheMadKing]

you want to measure your pH about 20 minutes into the mash and it should be measured at room temperature, or compensated for temperature. You'll want your pH between 5.3 and 5.5 at room temp

32 grams of gypsum IS a ton. (I'm assuming you're making a 5 gallon batch here)

The most I've ever added to a 5 gallon batch is 5 grams.

The general advice that I've seen from the water gurus (Martin and Aj) is that it doesn't do you any good to mess with your water until you know exactly what's in it. So the first thing you need to do is send a sample of your well water to Ward Labs and get a water report.

Then I recommend downloading the Bru'n Water calculator and reading through the information in the instructions. It will teach you almost everything you need to know about brewing water.

Then use the calculated as per the instructions.

Simply adding gypsum to lower the pH is a bad idea. Gypsum adds sulfate to your water which enhances bitterness perception in reasonable amounts (up to 350 ppm in a hoppy beer). According to the Bru'n water calculator, 35 grams of gypsum puts you at over 750 ppm of sulfate assuming you started with 0 (which you probably didn't). That's waaaay too much and you'll likely have a harshly bitter and undrinkable beer.

If you merely want to lower your mash pH you should be using lactic acid, but again, you need to know what's in your water so you can make an educated guess on how much lactic you need BEFORE you mash in since making pH adjustments on the fly isn't recommended.

 

[hardrain]

Thanks all, I'll chalk this one up to learning just enough to be dangerous. I've brewed mostly dark beers, and every IPA attempt I've made has tasted the same with no hop pop at all, thus my dive into water chemistry, which I suspect the culprit.

I read narrowly to simply figure out how to get the ph down, and then stopped reading . So big mistake. It sounds like I'm at 750+ ppm, and I'm seeing some recommended maximum levels of total sulfates in drinking water in the 250-500 range, side effects being gas and indigestion, with rare instances of worse I guess. I'll go ahead and use this one as a sample of "too much sulfate" for my palate training and move on .

My state tests water but I have to wait for one of their sessions, I have the materials and will send it off when I can. I do think I'm dealing with "STUPIDLY alkaline." Those number above are at mash temp, not room temp, so my room temp mash, even after that brain-dead amount of gypsum, was likely in the 6.0-6.3 range.

For fun I took the ph of my coffee this morning -- black, medium roast -- and got a 5.9 at room temp. My understanding is that's very high for coffee. So if coffee isn't getting the ph down...

Calibration could be an issue but I just did that 3 weeks ago, and many of my other readings (distilled water, star san) show at expected levels, but in any case another calibration won't hurt to find out for sure.

I'm brewing my first porter tomorrow since buying a ph meter and now this has me a little nervous. I've been able to make very good dark beers, and I quickly understood why once I started reading about water, but even still I'm super curious to find out if even a porter grain bill is actually getting me into the proper ph range, or if the darkness of the porter is just covering up negative implications of a high ph mash.

In any case I'm going to stop messing with the water until I get the test results back.

 

[MagicMatt]

Those number above are at mash temp, not room temp, so my room temp mash, even after that brain-dead amount of gypsum, was likely in the 6.0-6.3 range.

You shouldn't be taking pH at mash temps! That can easily destroy your pH meter's probe (or at least diminish the ability to accurately measure). The temp on any sample should be as close to room temp as possible, and definitely well under 100°F. An often used idea is to put a shot glass in the freezer an hour or so before you're ready to take a sample. Use this to take the sample, and it should be cooled enough within 5 minutes or so.

Calibration could be an issue but I just did that 3 weeks ago, and many of my other readings (distilled water, star san) show at expected levels, but in any case another calibration won't hurt to find out for sure.

3 weeks?!? Yeah, that's definitely an issue! You need to calibrate every single time you use it. Not necessarily before every measurement, but absolutely at the beginning of each brew day. And I'd keep the buffers around for the length of brew day so that you can periodically check to ensure the calibration has not strayed a bit for subsequent measurements. It's not uncommon for me to calibrate the meter twice on a given brew day.

I'm brewing my first porter tomorrow since buying a ph meter and now this has me a little nervous. I've been able to make very good dark beers, and I quickly understood why once I started reading about water, but even still I'm super curious to find out if even a porter grain bill is actually getting me into the proper ph range, or if the darkness of the porter is just covering up negative implications of a high ph mash.

In any case I'm going to stop messing with the water until I get the test results back.

I think if your water is as bad as you suspect, then the best option you have is to abandon it all together. You should read (and reread) the Water Chemistry Primer in the Brew Science section. It's likely going to be the best way for you to move forward.

The key is to start with a blank canvas - meaning use only distilled or reverse osmosis water. You could actually use a portion of your tap water and just dilute with RO or DI, but without knowing the specific levels of minerals in your tap water you'd still be taking a big guess. So it is better to just use filtered water. This way you know the mineral content (nearly zero), you know the pH (5.6-7 usually), and you know what adding 'x' amount of a given salt will do to that water.

You should also look into using a water chemistry calculator tool. There are a few different ones around, some more involved than others. To get started, I would recommend the Brewer's Friend Water Chemistry Calculator. It's pretty straight forward, and you'll get a really good idea of how adding different levels of salts will affect the overall beer. If you want to really get into it, there's an Advanced Version that you can even input your grist information and it will help determine the pH of the mash in addition to the overall beer properties. It may take a bit to get the hang of it, but it is pretty straight forward. There's also a spreadsheet version of this called Bru'nWater that's readily available on the internet, however this one can be a bit more intimidating for a novice. I would recommend getting the hang of it with one of the first links and then move to the spreadsheet when you're ready.

 

[hardrain]

And I'd keep the buffers around for the length of brew day so that you can periodically check to ensure the calibration has not strayed a bit for subsequent measurements.

Thanks Matt, didn't realize the need for frequency. For the solutions, do you store them over a period of time or remix for each use?

 

[Qhrumphf]

Thanks Matt, didn't realize the need for frequency. For the solutions, do you store them over a period of time or remix for each use?

You'll probably find it best to buy the liquid calibration buffer solutions in moderately larger bottles, but unless you're brewing constantly, I wouldn't get the BIGGEST ones. I use the 230ml bottles.

As suggested, keep the buffer solutions out on brew day and if you start to suspect the reading you can recheck calibration. Typically my step in the process, I overhead my strike water before adding to my cooler MLT, and then let it cool in the MLT to temp. It's during that time that I calibrate my pH meter, and then store the probe in water during brew day. I typically don't measure anything further beyond sparge runnings pH, so it's not out particularly long.

But never pour your used solutions back into the bottle as they can potentially shift the pH and make the whole bottle worthless. Over one brew, or two to three brews in one day, I'd say leaving the same buffer solution out and reusing if necessary is fine. But I wouldn't continue to use it the same day.

Long winded explanation cut short, with new calibration buffer (and cleaning/storage) solutions as needed, and brewing 2-3 batches per month, 230ml bottles last me a few months before needing replacement. They sell bigger ones (up to and beyond a liter IIRC), but I think I recall reading that the shelf life is <1 year for those solutions (edit: some searching suggests 3-6 months once the bottle is opened, for 4.01 and 7.01 buffers, less for 10+, but I never use those since I never measure anything that alkaline), so it may not be worth getting that size if you won't use them enough. If you brew several times a week, then the bigger bottles may be a good investment.