The mash pH of malts rises (by as much as 0.6 points) with increased crush size

[Silver_Is_Money]

Per this dissertation, presuming that I'm reading it correctly.

https://content.sciendo.com/downloadpdf/journals/agriceng/22/4/article-p43.pdf

I was not expecting that. It means that crush size is a vital component to consider for mash pH prediction software.

 

[Robert65]

I recall something in the Palmer and Kaminski book referencing studies showing that buffering capacity varies with crush as well. Kind of makes sense, as malt has more interface with water, and sooner, as particle size decreases.

 

[Silver_Is_Money]

Perhaps mash pH prediction software should come with a disclaimer that mash pH predictions are only valid for malts crushed to a specific mill gap specification.

 

[dmtaylor]

The key takeaway I see is that if you don't crush your malt for sh**, your mash pH is going to be pretty high. But if you crush like you should (i.e., lots of flour), then you'll get the pH that you should.

 

[mongoose33]

The key takeaway I see is that if you don't crush your malt for sh**, your mash pH is going to be pretty high. But if you crush like you should (i.e., lots of flour), then you'll get the pH that you should.

I don't agree about the flour thing, i.e., "like you should." Avoiding flour is one of the LODO precepts, and those doing LODO try to keep that flour down to a minimum. Can't avoid it, but it's not a given that lots of flour is desirable.

If all you're concerned with is conversion, maybe, but there are other considerations such as malt flavors.

 

[dmtaylor]

I don't agree about the flour thing, i.e., "like you should." Avoiding flour is one of the LODO precepts, and those doing LODO try to keep that flour down to a minimum. Can't avoid it, but it's not a given that lots of flour is desirable.

If all you're concerned with is conversion, maybe, but there are other considerations such as malt flavors.

Apologies to LODO protagonists. All I'm concerned about is consistent great beer with minimal effort. LODO is not minimal effort.

 

[bierhaus15]

Don't apologize. The majority of so-called LODO brew houses are wet-hammer milling to produce extremely fine grists for use in mash filters. This achieves maximum efficiency, achieves stable mash and lauter pH, and reduces wort oxidation. And an acceptable amount of fines are beneficial in wort as it aids with the post boil removal of bitter-polyphenols, tannins, reduces wort bitterness, and increases rate of fermentation. The aim of achieving crystal clear wort is largely an outdated practice, as the benefits of some wort turbidity outweigh its absence; and the negative attributes towards oxidation can be ameliorated via enzymes and additives such as brewtan. Even the use of 45g/hl of whole leaf hops added in the mash and kettle provide comparable protection against wort oxidation as enzyme use. In short, grind fine, but not to flour, and don't worry about some fines in your kettle.

 

[eric19312]

Don't apologize. The majority of so-called LODO brew houses are wet-hammer milling to produce extremely fine grists for use in mash filters. This achieves maximum efficiency, achieves stable mash and lauter pH, and reduces wort oxidation. And an acceptable amount of fines are beneficial in wort as it aids with the post boil removal of bitter-polyphenols, tannins, reduces wort bitterness, and increases rate of fermentation. The aim of achieving crystal clear wort is largely an outdated practice, as the benefits of some wort turbidity outweigh its absence; and the negative attributes towards oxidation can be ameliorated via enzymes and additives such as brewtan. Even the use of 45g/hl of whole leaf hops added in the mash and kettle provide comparable protection against wort oxidation as enzyme use. In short, grind fine, but not to flour, and don't worry about some fines in your kettle.

I know it's lazy but can you link me to a reference for the benefit of addition of whole leaf hops in the mash. Makes a lot of sense when you mention it but given the specificity of the number I'm guessing there is a decent article somewhere.

 

[mongoose33]

Don't apologize. The majority of so-called LODO brew houses are wet-hammer milling to produce extremely fine grists for use in mash filters. This achieves maximum efficiency, achieves stable mash and lauter pH, and reduces wort oxidation. And an acceptable amount of fines are beneficial in wort as it aids with the post boil removal of bitter-polyphenols, tannins, reduces wort bitterness, and increases rate of fermentation. The aim of achieving crystal clear wort is largely an outdated practice, as the benefits of some wort turbidity outweigh its absence; and the negative attributes towards oxidation can be ameliorated via enzymes and additives such as brewtan. Even the use of 45g/hl of whole leaf hops added in the mash and kettle provide comparable protection against wort oxidation as enzyme use. In short, grind fine, but not to flour, and don't worry about some fines in your kettle.

If I could crush finely in the absence of oxygen, I would. At the homebrew level this is well-nigh impossible.

 

[bierhaus15]

I know it's lazy but can you link me to a reference for the benefit of addition of whole leaf hops in the mash. Makes a lot of sense when you mention it but given the specificity of the number I'm guessing there is a decent article somewhere.

There are a bunch out there, have access to WBC material? 40-50g/hl is generally the min accepted rate of antiox benefits of hops. Without digging, here is one that uses hop leaves (as plant material) as source for antioxidants. Aside, German whole leaf hops tend to contain more leaf material and have greater impact than pellets.

"An Enzymatic and Hop Solution to Avoid Oxidation of Wort and Improve Beer Flavour Stability" - Carleton and United Breweries

If I could crush finely in the absence of oxygen, I would. At the homebrew level this is well-nigh impossible.

And what is so bad about oxygen exposure to malt when milling that you'd willingly sacrifice wort quality? Especially for home brewers, there are so many more processes that affect beer oxidation more so than malt oxidation. I'd also argue that the average home brewer would see a far better impact on their overall beer flavor from a tight crush and lower mash pH... and subsequently better fermentation performance due to proper lipids, ect, than the rather insignificant negative effects from milling with 02 exposure.

 

[mongoose33]

And what is so bad about oxygen exposure to malt when milling that you'd willingly sacrifice wort quality?

It has a deleterious effect on flavors. And what makes you think I'm sacrificing wort quality?

Especially for home brewers, there are so many more processes that affect beer oxidation more so than malt oxidation.

Sure there are more, but that doesn't mean you should just ignore malt oxidation.

I'd also argue that the average home brewer would see a far better impact on their overall beer flavor from a tight crush and lower mash pH... and subsequently better fermentation performance due to proper lipids, ect, than the rather insignificant negative effects from milling with 02 exposure.

Maybe that's so, but I'm not an average home brewer. I'm looking for every edge I can get to enhance flavors. Maybe that's not important to you, and if not, that's ok. Everybody doesn't have to be like me.

Nor you.

 

[eric19312]

FWIW I tested crushing fine enough to stick my recirculation last batch and was surprised with a lower than expected pH. Got some rice hulls in there and did get great efficiency but 5.25 mash pH at 30 min vs 5.4 - 5.5 target was a surprise.

 

[Spartan1979]

I use EZ Water and my actual results are always lower than the model predicts. Maybe my crush explains that?

 

[dmtaylor]

I use EZ Water and my actual results are always lower than the model predicts. Maybe my crush explains that?

Yep. Crush till your friends are scared. Then you know you’re doing it right.

 

[balrog]

Tighten the corona until you see metal flakes, then back off.

But just a little.

 

[mongoose33]

I use EZ Water and my actual results are always lower than the model predicts. Maybe my crush explains that?

I use EZWater as well, and I get the same pattern, the result is lower than the prediction. I just assume that whatever EZWater gives me, it'll be at least .2 lower.

 

[balrog]

On average, over last 22 batches, MpH, WaterEngine, EZWater predict 0.1 higher than measured
BnW predicted 0.1 lower than measured
BF and MME are, respectively, 0.02 higher/lower than measured.
And differences are inversely proportional to SRM of the batch, lower SRM has bigger diffs between predictions and measured.

I'm still using them all and measuring, but I go with BrewersFriend for now. Fact is, if I don't put in the right diph for each malt used I cannot and can never expect a good prediction.