Is the recipe calculator ph determination out of wack?

[MBCo]

For a long time the predicted ph the recipe builder ph was pretty darn close to what I actually measures. Now it seems it calculates the ph much lower than previously. What gives?

 

[Yooper]

We haven’t changed anything- is maybe the grain choice or the water choice different in your recipes?

 

[MBCo]

Hey Yooper:

I think it has something to do with pulling malt form my inventory.

Pulling UK roasted barley, for example, from my inventory has a much different effect than if i pull it from the general list.

I even deleted the inventory item and added it back, just in case I did something to booger it up. Same result.

 

[Lordie]

I've noticed the same thing. Without dark malts the calculated pH is spot on with my measurements, but my dark beers are way out of whack. Brewed my 60 shilling with extra dark caramel and roasted barley yesterday, which had a calculated pH of 4.95, but actual measurements were 5.65. Luckily I never trusted the calculated pH to begin with, so I was able to fix it w/o extra salts, but now I'll have to go manual with the salt additions until I get it right through trial and error.

 

[MBCo]

It sucks. I gravitated to brewers friend because if the fairly accurate Ph prediction and water calculator. It seems correct if I don't build a recipe from my inventory. That's okay as long as when I create a brew session it can match up and pull from my inventory list.

 

[Yooper]

I've noticed the same thing. Without dark malts the calculated pH is spot on with my measurements, but my dark beers are way out of whack. Brewed my 60 shilling with extra dark caramel and roasted barley yesterday, which had a calculated pH of 4.95, but actual measurements were 5.65. Luckily I never trusted the calculated pH to begin with, so I was able to fix it w/o extra salts, but now I'll have to go manual with the salt additions until I get it right through trial and error.

Can you grab a screenshot of the water calc where those grains are pulled in? I think it has something to do with that, but I cannot recreate it on my end.

 

[Lordie]

Can you grab a screenshot of the water calc where those grains are pulled in? I think it has something to do with that, but I cannot recreate it on my end.

My mistake. It's the Crisp Pale Chocolate that is off. I had run out of roasted barley and substituted the pale chocolate at the last minute, and just happened to mess with the water profile at the same time.

 

[Yooper]

My mistake. It's the Crisp Pale Chocolate that is off. I had run out of roasted barley and substituted the pale chocolate at the last minute, and just happened to mess with the water profile at the same time.

I don't know what you're saying- the SRM of the pale chocolate is incorrect, or everything is actually ok?

 

[Lordie]

I don't know what you're saying- the SRM of the pale chocolate is incorrect, or everything is actually ok?

What I meant to say is that the 4.95 pH that was calculated but measured 5.65 was with a last minute change to the recipe to crisp pale chocolate. My reference to roasted barley was from memory based on what I normally use.

I don't know what brand pale choc I had on hand when I made the substitution but playing with the calc this morning I found both generic UK roasted barley and UK pale chocolate gave the same calculated pH of 5.39. Switching to Crisp pale choc tanks it to 4.95, but I'm not sure if that would be normal for this particular brand of malt.

Either way something seems off, as my measurements of 5.65 were far higher than either calculation for this recipe. I'll pay more attention going forward and let you know.

 

[Nosybear]

Yooper, does the calculator take into account that roasted grains (black patent, etc.) aren't as acidic as say high lovibond Crystals? I've noticed that the pH on my mashes tends to be high when I use a lot of roasted grain. I can't remember the reference but I seem to remember the acidity goes up for crystal/caramel malts but tends to be at a very narrow, and lower, range for higher roasted grains.

 

[Yooper]

Yooper, does the calculator take into account that roasted grains (black patent, etc.) aren't as acidic as say high lovibond Crystals? I've noticed that the pH on my mashes tends to be high when I use a lot of roasted grain. I can't remember the reference but I seem to remember the acidity goes up for crystal/caramel malts but tends to be at a very narrow, and lower, range for higher roasted grains.

Yes, but it's not a huge difference in most cases. For example, if you add pale chocolate malt as roasted, the projected pH here is 5.41:

Changing that to crystal malt makes the pH a tiny bit lower:

Of course, using a 500L black malt would mean a much greater difference, showing a mash pH of 5.28 using that as a crystal malt!