Ph impact of Brown and Amber Malts

[WinterWarlock]

I'm about to brew Barclay Perkins 1804 TT Porter, which has a high percentage of brown malt, as well as some Amber malt, and I'm pondering what I'm going to do in terms of a water profile. The spreadsheets I'm familiar with don't have a selection for brown or amber malt. I imagine the ph impact of Brown Malt isn't quite strong as dark roasted malts. However, I'm guessing it could be more acidic than your standard crystal with a similar lovibond. Anyone have any thoughts about formulating a good water profile for this kind of recipe? I might go heavier on the minerals than usual to keep it British. Should be a fun brew session. Here's the recipe:

1804 Barclay Perkins TT Porter

1.061 OG
1.014 FG
6.16%ABV
63.7 IBUs

5.5 lb United Kingdom - Pale 2-Row 2.5L 40.7%
6.25 lb United Kingdom - Brown 65L 46.3%
1.75 lb United Kingdom - Amber 27L 13%

 

[mabrungard]

I find that those malts track reasonably as base malts with their color rating input as reported for the grain.

 

[thehaze]

I would probably go 50-60 ppm chloride and the same for sulfate. 5-10 ppm Mg, 50 ppm Ca and maybe 5-10 Na. Mash pH around 5.4-5.45.

If you use Bru'nWater, you can add Brown and Amber malt as Crystal malt or roasted. You can also add it as Crystal and instead of 65L, use 120L, to counteract the supossedly higher acidity. But I would not. Bru'nWater is pretty OK in helping you hit mash pH.

 

[WinterWarlock]

Excellent, thanks!

 

[mabrungard]

Since BP was a Porter brewery in London, it very likely obtained its water from wells drilled into the Chalk aquifer below the London clay. That water does have a bit of chloride and sodium along with significant hardness from Ca and Mg. There wasn't a lot of sulfate.

There is an article on London water in a Zymurgy issue from several years ago that can provide better guidance.

 

[Silver_Is_Money]

In 'Mash Made Easy' the brown malt would be entered as a brown malt, and the amber malt would best be entered as a specialty malt.

 

[ajdelange]

The only way to tell how the Brown malt is going to react is to measure its DI mash pH and buffering. There was a rather lengthy discussion of this very question earlier this year and the guy that kicked it off actually made some measurements but he wasn't experienced in this kind of work so that his results have to be taken as anecdotal at best. You had really better go search for that thread because anyone who relies on my memory does so at his own peril. Nonetheless, if I recall correctly, the DI mash pH was comparable to other malts of similar color but it appeared that the buffering was about twice normal.

 

[WinterWarlock]

Thanks everyone. Really appreciate the input. DeLange and Brungard weighing in on my water questions? Stoked!

 

[rhys333]

I'm brewing a brown porter over Christmas, and I'm going through my notes to see how it affected mash pH on previous batches. For me, it behaved much like roasted and crystal malts of similar colour (70L). Importantly, not as a 70L base malt.

For example, a standard strength porter with 10% brown malt, and a balanced water profile plus 1g of baking soda. If I label the brown malt as either a roast or crystal malt, I get a predicted mash pH of 5.44. This is close to actual results. If I were to instead label the brown malt as a base malt, I get a prediction of 5.27 which is far too low.

 

[CascadesBrewer]

I use Bru'n Water for my calcs and I am surprised how often my measured pH is within 0.02 of the predicted pH. I don't have 100% confidence in my exact tap water numbers, the reading from my cheap pH meter, or my process; but having matching numbers gives me some confidence.

The two batches since I started measuring pH in early 2019 that have been significantly off were two Brown Porters made with Crisp Brown Malt (65L). The first batch had 1.5 lbs of Brown Malt, and I measured a pH of 4.99 vs the calculated 5.36.

I brewed that batch again last week. I adjusted the recipe down to 1 lb of Brown Malt (for taste preference) and I added Baking Soda to up my target pH with the idea that I might come in low once again. I treated the Brown Malt as a Roasted malt.

Playing with the type for the Brown Malt I get:

• Base = 5.64
• Crystal = 5.65
• Roast = 5.53
• Measured = 5.39

 

[mabrungard]

I brewed that batch again last week. I adjusted the recipe down to 1 lb of Brown Malt (for taste preference) and I added Baking Soda to up my target pH with the idea that I might come in low once again. I treated the Brown Malt as a Roasted malt.

Playing with the type for the Brown Malt I get:

• Base = 5.64
• Crystal = 5.65
• Roast = 5.53
• Measured = 5.39

Those tweener grains are a real head scratcher. I also like Crisp brown malt since I find it delivers a slight smoke note that I like. Yeah, I’ve had lower than calculated pH with that grain when assuming its a base grain type. As you point out, the acidity of that brown malt is higher than anything I’ve got in the grain types.

It seems to be hair-pulling time.