Mash pH question

[Black_Z28]

Hello all, I have a question regarding mash pH. I brewed my first beer with water adjustments yesterday. But I have a few questions on my pH test during the mash.

First I'll say I'm on well water, and my alkalinity is high, so I'm adjusting using a 85% Phosphoric acid. Using Brun water I found i should add 8ml of acid, 2 gallons of distilled water and .25g of calcium chloride and gypsum. My system is a BIAB, so 7.25 total gallons in the mash.

I brewed a NEIPA
11lbs 2 row
3 lbs of flaked wheat/oats

Using an Apera PH60, which from my understanding is pretty reliable.

So I mashed in and thought what the heck I'll check the mash pH. And my pH was ridiculously low, 2.9. I found that weird, but just kept things rolling. I again checked at about 25 minutes in and my mash was at 5.4, right where it needed to be. So I guess my question is, why did I see such a low ph, shouldn't it be around 5.2??

I'm just starting to get into the whole pH thing so just looking for a little more understanding.

 

[Dgallo]

Hello all, I have a question regarding mash pH. I brewed my first beer with water adjustments yesterday. But I have a few questions on my pH test during the mash.

First I'll say I'm on well water, and my alkalinity is high, so I'm adjusting using a 85% Phosphoric acid. Using Brun water I found i should add 8ml of acid, 2 gallons of distilled water and .25g of calcium chloride and gypsum. My system is a BIAB, so 7.25 total gallons in the mash.

I brewed a NEIPA
11lbs 2 row
3 lbs of flaked wheat/oats

Using an Apera PH60, which from my understanding is pretty reliable.

So I mashed in and thought what the heck I'll check the mash pH. And my pH was ridiculously low, 2.9. I found that weird, but just kept things rolling. I again checked at about 25 minutes in and my mash was at 5.4, right where it needed to be. So I guess my question is, why did I see such a low ph, shouldn't it be around 5.2??

I'm just starting to get into the whole pH thing so just looking for a little more understanding.

As the water is extracting starches and minerals from gains, A pale mash will become more basic. At which temps are you taking measurements?

 

[couchsending]

What is your alkalinity? That’s a ton of 85% phosphoric.

 

[Black_Z28]

As the water is extracting starches and minerals from gains, A pale mash will become more basic. At which temps are you taking measurements?

Mash temps, so 150°.

What is your alkalinity? That’s a ton of 85% phosphoric.

About 350. I know it's high, but just trying to use my water and see how it goes before going RO.

 

[Dgallo]

Mash temps, so 150°.



About 350. I know it's high, but just trying to use my water and see how it goes before going RO.

Should be checking ph at room temp

 

[Black_Z28]

Should be checking ph at room temp

I'm sorry, I might have misread the post. I got the wort cooled to about 90° when I checked the pH and saw 2.9.

 

[couchsending]

Mash temps, so 150°.



About 350. I know it's high, but just trying to use my water and see how it goes before going RO.

You’d be better off preboiling your water and decanting as long as you Ca is relatively high as well.

Mine is 240ish and I would never even bother using it without preboiling it fist. I can get alkalinity down to around 80 that way.

 

[Black_Z28]

You’d be better off preboiling your water and decanting as long as you Ca is relatively high as well.

Mine is 240ish and I would never even bother using it without preboiling it fist. I can get alkalinity down to around 80 that way.

My Ca is 83.1 via my water test.

How do you know how much you dropped the alkalinity after boiling?

 

[SanPancho]

Your initial measurement was wrong. Either the probe misread, or you didn’t have things mixed thoroughly and sampled a pocket of acid. Neither malt has that low of a ph.

If you measure at mash temp add about 0.3 to your reading. If at room temp no adjustment.

Remember to calibrate.

 

[Robert65]

Your initial measurement was wrong. Either the probe misread, or you didn’t have things mixed thoroughly and sampled a pocket of acid.

This.

 

[Black_Z28]

Thanks guys. I figured there had to be some sort of oddity that happened. Just didn't make sense.

 

[Silver_Is_Money]

The perspective as to how much it didn't make sense is as follows:

10^-2.9/10^-5.4 = 316

2.9 pH is 316 times more acidic than 5.4 pH, all else being equal.

 

[couchsending]

My Ca is 83.1 via my water test.

How do you know how much you dropped the alkalinity after boiling?

There’s an equation, you can find it online. You can input your Ca and bicarbonate values and it will tell you how much you’ll end up with after boiling. I don’t know it well but I believe you’re gonna have to add some Ca in order for it to work well enough to get alkalinity down.

I personally wouldn’t attempt to brew that many beers with alkalinity that high. That’s a ton of really strong acid to be using.

 

[Silver_Is_Money]

Boiling can't get your alkalinity below about 65-66 ppm (which is the same as saying bicarbonate can't be reduced below ~80 ppm). And there must be sufficient calcium present in order to get the alkalinity to go that low during the boil, plus there must be a surplus of at least 12 ppm excess calcium ions remaining post the boil.

 

[Silver_Is_Money]

I found this equation in a post by Martin Brungard on another forum:

Ending Ca (ppm) = Starting Ca (ppm) - ((starting HCO3 (ppm) - ending HCO3 (ppm))/3.05)

Knowing that ending HCO3- can't be made to go below ~80 ppm via boiling, this becomes:

Ending Ca (ppm) = Starting Ca (ppm) - ((starting HCO3 (ppm) - 80)/3.05)

Where ending Ca must be 12 or more ppm after solving the equation (and where if it is less than 12 ppm, more calcium must be added).

 

[couchsending]

But bicarbonate levels of 80 are much much easier to work with. I’ve made some pretty darn good beers with my horrible horrible well water with alkalinity over 240 using the boiling and decant method. Beers that scored in the mid 40s and ones that have won my state competition for IPA. It’s a huge PITA. But if you’re dead set on using your water it can be done..

That being said on anything low ABV and light in malt Id be very wary of tannin extraction in the sparge. On beers like that I tend to target something higher gravity but lower volume and then top up with water to hit gravity and volume. Beers end up much smoother.