Yet more evidence that commercial brewers do not mash at 5.2 to 5.6 pH ...

[Robert65]

The best index for gelatinization temperature is the Hartong VZ 45°C on the COA. The lower this number, the higher the gelatinization temperature. Here's a graph from a well known article from Brauwelt International:

 

[Silver_Is_Money]

The best index for gelatinization temperature is the Hartong VZ 45°C on the COA. The lower this number, the higher the gelatinization temperature.

That information for base malts seemingly might make a great guide for choosing a single infusion mash temperature target. Is it available from all maltsters? My problem here is that I generally purchase only enough malt to do a batch, and the malt often comes from bulk bins with zero attached analytical info.

As you are reasonably well known for mashing at a higher target pH than most, might you offer us some insight into the benefit(s) you perceive in so doing?

 

[Silver_Is_Money]

wrt pH 5.8 - isn't that verging on the threshold of releasing tannins from husks, especially given the duration [edit: and temperature] of a typical mash?

I've mentioned a few times within this and other threads that if Stan Hieronymus, the author of 'Brew Like A Monk' is correct, the Rochefort Monastery brewery in Belgium intentionally mashes at pH 5.8 to 5.9 pH. As I recall, their waters alkalinity is in the ballpark of 160 ppm, and they only acidify (targeting pH 5.2) post mash and pre-boil.

 

[dmtaylor]

Since increasing my pH to 5.5-5.6, over 3 out of the last 4 batches, I've had an average efficiency of 71%, just about my lowest ever, except for my brown ale which had 88% -- odd fluke!? Perhaps the darker malts lowered the pH when I wasn't looking? This last Sunday I just mashed a Kolsch-style at pH 5.65 (actually measured 5.4 @ mash temp 149 F), that's the highest I think I've ever gone, and my brewhouse efficiency was 70%. I also tasted the wort, and it seemed remarkably insipid and boring compared to any other wort. But I'm fermenting it as-is to see how it all turns out in the end. My other beers turned out mediocre at best... except the brown ale won a gold medal. Coincidence?! I dunno yet.

So, I must say, I'm not really liking this higher pH thing as much as I'd expected. But will continue to toy with it. I think also I might try extending my mash time from 45 minutes to perhaps 75 minutes, to see if that helps much.

 

[Robert65]

That information for base malts seemingly might make a great guide for choosing a single infusion mash temperature target. Is it available from all maltsters? My problem here is that I generally purchase only enough malt to do a batch, and the malt often comes from bulk bins with zero attached analytical info.

As you are reasonably well known for mashing at a higher target pH than most, might you offer us some insight into the benefit(s) you perceive in so doing?

Recently, I've actually been mashing lower again. This is because I do low oxygen brewing, and I've added a lower temperature rest to accommodate a less well modified malt; as I'm now mashing in below the temperature for denaturation of LOX, the lower pH is another tool for suppressing LOX activity. (One of the factors Kunze takes into consideration I determining optimal pH.) I can't say I've seen any significant hit on efficiency, but rather an increase -- but I attribute this to the temperature program, which I specifically intended to address the higher glucan level of the particular malt. Anecdotally at this point (N = very low) I think I'm getting more dramatic hot breaks (egg drop soup,) but I don't see a difference in the quality of the chilled wort vis-à-vis fining performance, as long as the pH at knockout is in the same range (5.0-5.2.)

It may be that there is no one size fits all answer to optimize pH any more than any other parameter. Everything must be tailored to the malt, and to the specific goals we prioritize.

As for the numbers on a COA, different maltsters provide more or less complete reports. The Hartong VZ 45°C ought to be always reported, but that doesn't mean that it is. BSG's website has a tool for getting lot analyses of any products they distribute based on the lot number on the sack. I buy base malts by the sack, but if you don't, and it's a BSG-distributed product, perhaps your shop could note and provide the identifying information off the sack. Tracking this, it can be astonishing how much lot to lot variation there can be in some parameters in an "identical" malt.

 

[Silver_Is_Money]

Since increasing my pH to 5.5-5.6, over 3 out of the last 4 batches, I've had an average efficiency of 71%, just about my lowest ever, except for my brown ale which had 88% -- odd fluke!? Perhaps the darker malts lowered the pH when I wasn't looking? This last Sunday I just mashed a Kolsch-style at pH 5.65 (actually measured 5.4 @ mash temp 149 F), that's the highest I think I've ever gone, and my brewhouse efficiency was 70%. I also tasted the wort, and it seemed remarkably insipid and boring compared to any other wort. But I'm fermenting it as-is to see how it all turns out in the end. My other beers turned out mediocre at best... except the brown ale won a gold medal. Coincidence?! I dunno yet.

So, I must say, I'm not really liking this higher pH thing as much as I'd expected. But will continue to toy with it. I think also I might try extending my mash time from 45 minutes to perhaps 75 minutes, to see if that helps much.

Are you adjusting the Wort pH to 5.0-5.2 just before boiling?

 

[stevehaun]

The Weyermann publication titled "pH In The Brewery" offers confirmation as to why it isn't likely the best practice to mash at between 5.2 and 5.6 pH as measured at room temperature. Notice that the principle enzymes of our concern are at their peak of performance at high pH's as measured at their respective optimal temperatures. If we add a pH meter correction factor of 0.25 to better reflect these pH's at room temperature we get 5.65 to 5.85 pH as the optimal range for Beta-Amylase, and 5.85 to 6.05 as the optimal range for Alpha-Amylase. This lends support to the position behind this thread that the "ideal room temperature mash pH range" should be revised upward from the currently accepted 5.2-5.6 pH to 5.5-5.9 pH.

I would guess (I have not read the original papers) that pH optima for both beta and alpha amylase were determined in the laboratory using purified enzymes at a specified temperature as this is how enzymes are studied. In the lab, all pH readings are typically done at near room temp. I don't think adding the mash temp pH offset to these values makes sense. These pH optima were not determined in a mash.

 

[dmtaylor]

Are you adjusting the Wort pH to 5.0-5.2 just before boiling?

I have not. I will play with that on future batches.

 

[cire]

I've mentioned a few times within this and other threads that if Stan Hieronymus, the author of 'Brew Like A Monk' is correct, the Rochefort Monastery brewery in Belgium intentionally mashes at pH 5.8 to 5.9 pH. As I recall, their waters alkalinity is in the ballpark of 160 ppm, and they only acidify (targeting pH 5.2) post mash and pre-boil.

It would be a surprise if the Trappistes Rochefort 10 I recently drank was mashed as high as pH 5.8, it was just too smooth and sweet.

My studies into water treatment began when pH 5.3 was the accepted target and some of my dark beers were found to mash at 5.8. pH 5.6 is the highest I presently allow runnings to reach.

The Rochefort beer tasted strongly of dark crystal and the ingredients listed on the bottle are; water, malted barley, sugar, wheat starch, yeast, hop. 11.3% alcohol by volume with advised serving temperature of 12-14C (54-57F), it tasted like the grist had a good 15% dark crystal. It also had the body of a beer from good levels of both calcium and chloride that altogether suggest it would naturally mash at <pH 5.8 even with alkalinity of 160ppm.

The beer is worth buying, very nice.

 

[Die_Beerery]

Possibly. I have seen reports that some malts can have higher gelatinization temperatures than other malts. This can affect your conversion efficiency, which then affects mash efficiency, and all other downstream efficiencies. I've been thinking that the way to deal with such malts is to raise the mash temp up to 170°F, and rest for a while, then drop the temp and add alpha amylase to complete conversion. Or, you can just accept the lower eff.

Brew on

Say what now????????? Thats joking right?!?

 

[Silver_Is_Money]

It would be a surprise if the Trappistes Rochefort 10 I recently drank was mashed as high as pH 5.8, it was just too smooth and sweet.

My studies into water treatment began when pH 5.3 was the accepted target and some of my dark beers were found to mash at 5.8. pH 5.6 is the highest I presently allow runnings to reach.

The Rochefort beer tasted strongly of dark crystal and the ingredients listed on the bottle are; water, malted barley, sugar, wheat starch, yeast, hop. 11.3% alcohol by volume with advised serving temperature of 12-14C (54-57F), it tasted like the grist had a good 15% dark crystal. It also had the body of a beer from good levels of both calcium and chloride that altogether suggest it would naturally mash at <pH 5.8 even with alkalinity of 160ppm.

The beer is worth buying, very nice.

Per the book their calcium is 82 ppm, Sulfate is 32 ppm, and Chloride is 17 ppm. Bicarbonate is 240 ppm. Magnesium is 10 ppm. Sodium is 6 ppm.

The bicarb would indicate alkalinity at around 196 ppm (vs. 160 ppm, which was off the top of my head). The book does confirm that they mash at 5.8-5.9 pH.

 

[dmtaylor]

Say what now????????? Thats joking right?!?

Sounds like a need for decoction!

 

[Die_Beerery]

Sounds like a need for decoction!

I can pretty much guarantee there isn't a malt that has a gelat temp above 153. However, yes, decoction would negate that proposed madness!

 

[Silver_Is_Money]

Of late I've been combing through peer reviewed dissertations on "Limit Dextrinase", which is an enzyme that can convert starches which are not convertible via alpha or beta amylase into fermentable sugars. It seems that the room temperature measured mash pH range which most promotes the action of Limit Dextrinase is 5.0 to 5.5, with a slight peak at 5.5. Thus if maximum conversion is desired via maximizing Limit Dextrinase, a somewhat lower mash pH target may prove to be the ticket, but I would intuitively presume that this may lead to thinner beer from the perspective of mouthfeel.

 

[dmtaylor]

Of late I've been combing through peer reviewed dissertations on "Limit Dextrinase", which is an enzyme that can convert starches which are not convertible via alpha or beta amylase into fermentable sugars. It seems that the room temperature measured mash pH range which most promotes the action of Limit Dextrinase is 5.0 to 5.5, with a slight peak at 5.5. Thus if maximum conversion is desired via maximizing Limit Dextrinase, a somewhat lower mash pH target may prove to be the ticket, but I would intuitively presume that this may lead to thinner beer from the perspective of mouthfeel.

Limit dextrinase though is as fussy as beta amylase, and quickly denatures above 65 C or 149 F. As such I don't know how useful it truly is in most mashes unless fussing around with step mashing etc. Personally I don't bother, but yes it's another tool in the toolbox, another variable that can be played with.

 

[Robert65]

With multiple "beta" rests, say 20 minutes at 144°F and then a longer one above whatever gelatinization temperature is for the malt, instead of just the one at or above gelatinization temperature, I can get a little higher extract a little faster maybe, but other factors affect that much more. But my lager yeast will go from ~80% AA to ~85%. pH around 5.4 is apparently optimal for extract, but again, time and temperature are far more effective in manipulating these enzymes than pH. Allowing limit dextrinase and beta amylase more opportunity to play together does significantly affect attenuation limit.

 

[Silver_Is_Money]

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Limit dextrinase though is as fussy as beta amylase, and quickly denatures above 65 C or 149 F. As such I don't know how useful it truly is in most mashes unless fussing around with step mashing etc. Personally I don't bother, but yes it's another tool in the toolbox, another variable that can be played with.

I believe that I came across where a few of the researchers have determined that pure limit dextrinase in water is indeed rapidly destroyed at single infusion mash temperatures, but when grist and wort are present about 60% of it may survive for about 45 minutes at ballpark 65 degrees C.

 

[Silver_Is_Money]

With multiple "beta" rests, say 20 minutes at 144°F and then a longer one above whatever gelatinization temperature is for the malt, instead of just the one at or above gelatinization temperature, I can get a little higher extract a little faster maybe, but other factors affect that much more. But my lager yeast will go from ~80% AA to ~85%. pH around 5.4 is apparently optimal for extract, but again, time and temperature are far more effective in manipulating these enzymes than pH. Allowing limit dextrinase and beta amylase more opportunity to play together does significantly affect attenuation limit.

Rob, are you still attempting to target 5.6 to 5.65 pH in the mash, or are you setting a lower target now?

 

[Silver_Is_Money]

Renowned brewing Scientist 'Ludwig Narziss' generally talks about 5.5 mash pH and 5.1 wort pH as targets. Can anyone with better access to his stuff (wherein I'm limited to what I can find for free on the internet) definitively peg down whether these are both to be considered by him as room temperature measures, mash temperature measures, or other?

 

[Die_Beerery]

He only decocts, so take the numbers with that in mind. Also PM for more N info.

 

[Silver_Is_Money]

He only decocts, so take the numbers with that in mind. Also PM for more N info.

PM sent.

 

[stevehaun]

What does mashing below the gelatinization temp get you? Seems you would be burning up (denaturing) your beta amylase while there is no substrate available...

 

[day_trippr]

I don't know if popular opinion these days supports an article like this, but at least wrt listing all of the various rests and why they are/were used it's an illuminating read...

https://byo.com/article/the-science-of-step-mashing/

Cheers!

 

[Robert65]

What does mashing below the gelatinization temp get you? Seems you would be burning up (denaturing) your beta amylase while there is no substrate available...

There is a whole lot of substrate available below gelatinization temperature, just not 100% of it. In fact at any temperature, as soon as malt is hydrated, all enzymes are active, so dough in can effectively done at lower temperatures. But above gelatinization temperature, beta's clock is running out very quickly. By creeping up through its range, you maximize it, getting it to do most of its work in its safest temperature range, and just mopping up at the end before alpha fully takes over. This gets you the maximum extract and highest fermentability, which is why multiple beta rests are SOP for German brewers, as German beers are (unlike most home and craft attempts at the styles) extremely well attenuated.

 

[Robert65]

Rob, are you still attempting to target 5.6 to 5.65 pH in the mash, or are you setting a lower target now?

Depends. When I dough in below 140°F (denaturation of LOX,) I may target 5.4 (5.2 or below at mash temperature) to inhibit it. But there are other ways to minimize its effects. There are a lot of considerations planning any mash, and as I think you've brought to light, pH is often not the most important thing, or the best tool. And everything is a compromise. Sorry, that's really not an answer, but there is no one answer. As i said, depends on the beer and the goals.

 

[stevehaun]

There is a whole lot of substrate available below gelatinization temperature, just not 100% of it. In fact at any temperature, as soon as malt is hydrated, all enzymes are active, so dough in can effectively done at lower temperatures. But above gelatinization temperature, beta's clock is running out very quickly.

Rob, you make a great point that is misunderstood by many brewers. Alpha and beta amylase are both active at temps in the 130s - their activity increases with temperature until they begin to be denatured. Activity vs. temperature curves for most enzymes are inverted U's. I was operating under the impression (evidently false) that starch molecules required gelatinization prior to becoming available substrate for amylase. Does anyone know what percentage of the starch is available to amylases prior to gelatinization?

 

[dmtaylor]

Rob, you make a great point that is misunderstood by many brewers. Alpha and beta amylase are both active at temps in the 130s - their activity increases with temperature until they begin to be denatured. Activity vs. temperature curves for most enzymes are inverted U's. I was operating under the impression (evidently false) that starch molecules required gelatinization prior to becoming available substrate for amylase. Does anyone know what percentage of the starch is available to amylases prior to gelatinization?

Picture gelatinization just like popcorn before and after being popped. You start with very hard steely kernels, which would be very difficult to eat -- might break your teeth, etc. But when gelatinized, the kernels explode into the much larger fluffy stuff we know as popcorn. You could try to eat the hard kernels without gelatinization and without chipping a tooth if you were to grind the hard kernels into flour. The effect in your stomach then were you to eat this flour would be about the same as eating popped popcorn -- instead of fluffy popcorn melting down into starch soup in your gullet, you’d right away have corn flour soup, which accomplishes the same thing, and your body would really see no difference between the two. But, if you instead only broke the kernels into 6 or 7 pieces each, like a brewer’s mill does, but didn’t grind it down to powdery flour, then not only would it be much more difficult to eat than the flour or the popcorn, but your body would find it more difficult to digest.

So this is all sort of an analogy for the difference between ungelatinized starch vs. gelatinized. Gelatinization is explosively beneficial to the enzymes, increasing surface area by thousands of times. Certainly, broken kernels are better than unbroken ones… but not by much. Flour would be just about as beneficial as gelatinization, but we don’t get a ton of flour out of a brewer’s mill typically. And, it could be argued that even flour isn’t quite as beneficial as gelatinization. Gelatinization is also probably the most energy efficient way to make the most starches available to the enzymes.

So…… that’s my story and I’m sticking to it, for now.

 

[stevehaun]

Even if you create flour, isn't gelatinization still required to open up the starch molecule?
When doing a cereal mash with corn meal (higher gelatinization temp than malted barley), you have to boil the corn meal before the malt amylases can break down the starches in the corn meal. Flaked maize is already gelatinized.

 

[dmtaylor]

Even if you create flour, isn't gelatinization still required to open up the starch molecule?
When doing a cereal mash with corn meal (higher gelatinization temp than malted barley), you have to boil the corn meal before the malt amylases can break down the starches in the corn meal. Flaked maize is already gelatinized.

Yeah, after I thought about it a while longer, I believe you are correct. Flour is much better than not-flour, and gelatinized is much better than not-gelatinized.

Cheers.

 

[Robert65]

Yeah, after I thought about it a while longer, I believe you are correct. Flour is much better than not-flour, and gelatinized is much better than not-gelatinized.

Cheers.

And yet we can measure conversion, and see that a significant portion of it is achieved below gelatinization temperature.... Looking at the record of just my last mash, which I have on hand, dough in at 135°F, ramp 2°F/min to 144° (gelatinization temperature of this particular lot of malt is 147°F,) after a 20 minute rest I was at 73% maximum first wort density, 30 minutes at 147°F got to 94%, 30 minutes at 162 to 100%.

I'll look through some articles when I get a chance. I know I have some actual information on this question of just how much starch is available when.