Ask The Brewmasters

Hello!

Here's one that has me puzzled. We thought to try performing an extended protien rest on a mash we were producing to make a kettle sour, as a means to not only promote the impact of  Protienase, Peptidase, and Beta-Glucanse, but to perhaps get a jump on lactic acid production via and LAB existing on the malt itself.

The pH effect was remarkable, of course. Mashed in at 120+/-, left overnight. pH fell from 5.24 to 3.6. We then raised the temp to 154 for a sacch rest, and then moved the mash to lauter. This is where the thing that is mystifying me happened. The mash was basically goo, and lauter was essentially impossible.

I am unaware of any enzyme/bacteria that would cause this to happen... What am I missing/not thinking of?

Thanks!

Jared Smith

Hello!

Here's one that has me puzzled. We thought to try performing an extended protien rest on a mash we were producing to make a kettle sour, as a means to not only promote the impact of  Protienase, Peptidase, and Beta-Glucanse, but to perhaps get a jump on lactic acid production via and LAB existing on the malt itself.

The pH effect was remarkable, of course. Mashed in at 120+/-, left overnight. pH fell from 5.24 to 3.6. We then raised the temp to 154 for a sacch rest, and then moved the mash to lauter. This is where the thing that is mystifying me happened. The mash was basically goo, and lauter was essentially impossible.

I am unaware of any enzyme/bacteria that would cause this to happen... What am I missing/not thinking of?

Thanks!

Jared Smith

Hello!

Here's one that has me puzzled. We thought to try performing an extended protien rest on a mash we were producing to make a kettle sour, as a means to not only promote the impact of  Protienase, Peptidase, and Beta-Glucanse, but to perhaps get a jump on lactic acid production via and LAB existing on the malt itself.

The pH effect was remarkable, of course. Mashed in at 120+/-, left overnight. pH fell from 5.24 to 3.6. We then raised the temp to 154 for a sacch rest, and then moved the mash to lauter. This is where the thing that is mystifying me happened. The mash was basically goo, and lauter was essentially impossible.

I am unaware of any enzyme/bacteria that would cause this to happen... What am I missing/not thinking of?

Thanks!

Jared Smith

Hello!

Here's one that has me puzzled. We thought to try performing an extended protien rest on a mash we were producing to make a kettle sour, as a means to not only promote the impact of  Protienase, Peptidase, and Beta-Glucanse, but to perhaps get a jump on lactic acid production via and LAB existing on the malt itself.

The pH effect was remarkable, of course. Mashed in at 120+/-, left overnight. pH fell from 5.24 to 3.6. We then raised the temp to 154 for a sacch rest, and then moved the mash to lauter. This is where the thing that is mystifying me happened. The mash was basically goo, and lauter was essentially impossible.

I am unaware of any enzyme/bacteria that would cause this to happen... What am I missing/not thinking of?

Thanks!

Jared Smith

Hello!

Here's one that has me puzzled. We thought to try performing an extended protien rest on a mash we were producing to make a kettle sour, as a means to not only promote the impact of  Protienase, Peptidase, and Beta-Glucanse, but to perhaps get a jump on lactic acid production via and LAB existing on the malt itself.

The pH effect was remarkable, of course. Mashed in at 120+/-, left overnight. pH fell from 5.24 to 3.6. We then raised the temp to 154 for a sacch rest, and then moved the mash to lauter. This is where the thing that is mystifying me happened. The mash was basically goo, and lauter was essentially impossible.

I am unaware of any enzyme/bacteria that would cause this to happen... What am I missing/not thinking of?

Thanks!

Jared Smith

I want to dovetail off of @Jeff Biegert's comment by adding that both alpha and beta amylase are only active from 5.0-6.0. With that in mind, my thinking is the same as Jeff's: very likely the issue is that your pH was so low that the enzymes couldn't do their job (i.e., it's not just that you weren't in the ideal range, you were well outside the active range). 

In terms of why it turned to goo, I'm less sure of that, but I wonder if it's a combo of proteinase, peptidases, and beta glucanase (and possibly phytase) working their magic for a long time in conjunction with an "overnight oatmeal" effect that @Bryan Doran referenced. 

Hello!

Here's one that has me puzzled. We thought to try performing an extended protien rest on a mash we were producing to make a kettle sour, as a means to not only promote the impact of  Protienase, Peptidase, and Beta-Glucanse, but to perhaps get a jump on lactic acid production via and LAB existing on the malt itself.

The pH effect was remarkable, of course. Mashed in at 120+/-, left overnight. pH fell from 5.24 to 3.6. We then raised the temp to 154 for a sacch rest, and then moved the mash to lauter. This is where the thing that is mystifying me happened. The mash was basically goo, and lauter was essentially impossible.

I am unaware of any enzyme/bacteria that would cause this to happen... What am I missing/not thinking of?

Thanks!

Jared Smith

Thanks for the replies, I will say this- @Jeff Biegert -

We tried twice. Iodine conversion test was performed on the first one and mash passed. Lauter was a fight but 8 hours later we had enough to run a short batch which fermented out to a lovely 1.5 plato.

Second time I wasn't around, fairly certain that the conversion was fine, but I am told the mash was so stuck, after re-setting/underlet and such that they ditched the project.

In the past I have successfully run several mashes where the pH was less than 4 for the sacch rest and had no conversion issues, or lauter issues... We have been doing a kettle sour at this brewery the same way as you mention Jeff, by adding LAB to the wort at 120, post mash and lauter. This 120 degree rest idea was an attempt to get our own unique flavor profile by getting the pH to adjust on it's own. 

@Liam Mckenna Thanks for that idea. I will explore that.

I want to dovetail off of @Jeff Biegert's comment by adding that both alpha and beta amylase are only active from 5.0-6.0. With that in mind, my thinking is the same as Jeff's: very likely the issue is that your pH was so low that the enzymes couldn't do their job (i.e., it's not just that you weren't in the ideal range, you were well outside the active range). 

In terms of why it turned to goo, I'm less sure of that, but I wonder if it's a combo of proteinase, peptidases, and beta glucanase (and possibly phytase) working their magic for a long time in conjunction with an "overnight oatmeal" effect that @Bryan Doran referenced. 

Hello!

Here's one that has me puzzled. We thought to try performing an extended protien rest on a mash we were producing to make a kettle sour, as a means to not only promote the impact of  Protienase, Peptidase, and Beta-Glucanse, but to perhaps get a jump on lactic acid production via and LAB existing on the malt itself.

The pH effect was remarkable, of course. Mashed in at 120+/-, left overnight. pH fell from 5.24 to 3.6. We then raised the temp to 154 for a sacch rest, and then moved the mash to lauter. This is where the thing that is mystifying me happened. The mash was basically goo, and lauter was essentially impossible.

I am unaware of any enzyme/bacteria that would cause this to happen... What am I missing/not thinking of?

Thanks!

Jared Smith

Thanks for the replies, I will say this- @Jeff Biegert -

We tried twice. Iodine conversion test was performed on the first one and mash passed. Lauter was a fight but 8 hours later we had enough to run a short batch which fermented out to a lovely 1.5 plato.

Second time I wasn't around, fairly certain that the conversion was fine, but I am told the mash was so stuck, after re-setting/underlet and such that they ditched the project.

In the past I have successfully run several mashes where the pH was less than 4 for the sacch rest and had no conversion issues, or lauter issues... We have been doing a kettle sour at this brewery the same way as you mention Jeff, by adding LAB to the wort at 120, post mash and lauter. This 120 degree rest idea was an attempt to get our own unique flavor profile by getting the pH to adjust on it's own. 

@Liam Mckenna Thanks for that idea. I will explore that.

I want to dovetail off of @Jeff Biegert's comment by adding that both alpha and beta amylase are only active from 5.0-6.0. With that in mind, my thinking is the same as Jeff's: very likely the issue is that your pH was so low that the enzymes couldn't do their job (i.e., it's not just that you weren't in the ideal range, you were well outside the active range). 

In terms of why it turned to goo, I'm less sure of that, but I wonder if it's a combo of proteinase, peptidases, and beta glucanase (and possibly phytase) working their magic for a long time in conjunction with an "overnight oatmeal" effect that @Bryan Doran referenced. 

Hello!

Here's one that has me puzzled. We thought to try performing an extended protien rest on a mash we were producing to make a kettle sour, as a means to not only promote the impact of  Protienase, Peptidase, and Beta-Glucanse, but to perhaps get a jump on lactic acid production via and LAB existing on the malt itself.

The pH effect was remarkable, of course. Mashed in at 120+/-, left overnight. pH fell from 5.24 to 3.6. We then raised the temp to 154 for a sacch rest, and then moved the mash to lauter. This is where the thing that is mystifying me happened. The mash was basically goo, and lauter was essentially impossible.

I am unaware of any enzyme/bacteria that would cause this to happen... What am I missing/not thinking of?

Thanks!

Jared Smith

Hi Jared,

Sorry to read about this.  It does bring to mind a few different thoughts.

My first encounter with a brewhouse delay and long mashing time was in Lake Oswego, OR (Saxer Brewing) in 1993.  Due to some issue, we faced a long delay in the mash tun.  Our German brewmaster told us the mash would be too sour and difficult to lauter, so it must be dumped.  The owner would have none of it, and we carried on.  I was new to the industry and three-hour lauter runs were normal for us, so I don't remember anything unusual from that day. 

As already mentioned, it sounds like gelatinization took place at 154°F, but at this point, the pH may have been too low for enzymes to function, and there was no liquefaction of the starch by alpha amylase.  Together, temperature and pH are key parameters for enzymes.

When did you first notice the goo?  In the mash or only in the lauter tun?  Was there a pump over from mash tun to lauter tun?  No problems, or also difficult?

And why did you get iodine negative for starch?  You would not see gelatinization of all the starch at 120°F, although some starch granules may have already started to gelatinize at this temperature.  If the pH were low enough, then there would be no liquefaction by alpha amylase.  This is the gravy effect:  You thicken a sauce by adding starch while cooking.

But I have also had one experience where iodine solution was old and not properly stored.  The result was a false negative and a 40 bbls cooker of grits that did not pump.  Clean up was difficult, too.   Make a fresh solution of iodine monthly and store it away from the light, keeping a portion for daily use in a small brown bottle, also stored away from light.  More information is in the ASBC Methods.  Make the iodine check with wort at room temperature, too, not with hot wort directly out of the mash tun.  

As mentioned, overnight oatmeal is very much a possibility.  There are a lot of enzymes in malt, and we normally focus on a few for fermentability and wort separation.  At 120 °F, many are still active.  Then, as for microorganisms on the malt, there are a lot of them, too, and each of these also have their own compliment of enzymes, all functioning within a specific pH and temperature range. 

Here is the list from Bokulich and Bamforth (2013) showing what has been found on the malt surface and in the mash:

Bacteria:  Bacillus, Flavobacterium, Alcaligenes, Pseudomonas, Enterobacteriaceae, Actinomycetales, Lactobacillus, Acetobacteriaceae.

Fungi:  Candid, Debaromyces, Hansenula, Hanseniaspora, Rhodotorula, Sporobolomyces, Trichosporon, Penicillium, Aspergillus, Alternaria, Fusarium, Epicoccum, Cladosporum, Botrytis, Aureobasidium, Absidia. 

A warm, moist environment supports the growth of most, if not all, of them.  Interestingly, for commercial enzyme application, we often encounter inhibitors in barley or wheat that specifically prevent attack from the microorganisms listed above.  They act as a defense mechanism limiting enzyme activity from these the attackers.  It's a brutal existence out in the field.    

As brewers, we want to capture nutrients from the malt to provide for yeast growth.  Plants (barley) and bacteria also utilize these same nutrients for their own growth.  It seems that all these enzymes in the mash at 120°F, sitting overnight, created one large digester with the main activity of breaking down all those large macromolecules into smaller, manageable pieces that could then be absorbed and utilized for energy and growth. 

Finally, while utilizing a sour mash is possible, it may be better to go through mashing and conversion first, as in any brew, then cool the mash to 120 °F.  You can also lauter, boil the wort, and then cool it to 120 °F and pump back to the kettle.  Both methods require that you inoculate with LAB afterwards, either a commercial product or with ground malt in a mesh bag or hop sock.  I am no expert on this, so I hope others can provide better guidance.  

I think you were on the right path for creating a unique sour mash, but the amount of malt used produced a result far beyond the capabilities of the brewhouse.  I would try again but with smaller amounts of malt in the mash or on bench top first.  There is always something new to learn in brewing and that is why brewing will never be boring. 

Thanks for the replies, I will say this- @Jeff Biegert -

We tried twice. Iodine conversion test was performed on the first one and mash passed. Lauter was a fight but 8 hours later we had enough to run a short batch which fermented out to a lovely 1.5 plato.

Second time I wasn't around, fairly certain that the conversion was fine, but I am told the mash was so stuck, after re-setting/underlet and such that they ditched the project.

In the past I have successfully run several mashes where the pH was less than 4 for the sacch rest and had no conversion issues, or lauter issues... We have been doing a kettle sour at this brewery the same way as you mention Jeff, by adding LAB to the wort at 120, post mash and lauter. This 120 degree rest idea was an attempt to get our own unique flavor profile by getting the pH to adjust on it's own. 

@Liam Mckenna Thanks for that idea. I will explore that.

I want to dovetail off of @Jeff Biegert's comment by adding that both alpha and beta amylase are only active from 5.0-6.0. With that in mind, my thinking is the same as Jeff's: very likely the issue is that your pH was so low that the enzymes couldn't do their job (i.e., it's not just that you weren't in the ideal range, you were well outside the active range). 

In terms of why it turned to goo, I'm less sure of that, but I wonder if it's a combo of proteinase, peptidases, and beta glucanase (and possibly phytase) working their magic for a long time in conjunction with an "overnight oatmeal" effect that @Bryan Doran referenced. 

Hello!

Here's one that has me puzzled. We thought to try performing an extended protien rest on a mash we were producing to make a kettle sour, as a means to not only promote the impact of  Protienase, Peptidase, and Beta-Glucanse, but to perhaps get a jump on lactic acid production via and LAB existing on the malt itself.

The pH effect was remarkable, of course. Mashed in at 120+/-, left overnight. pH fell from 5.24 to 3.6. We then raised the temp to 154 for a sacch rest, and then moved the mash to lauter. This is where the thing that is mystifying me happened. The mash was basically goo, and lauter was essentially impossible.

I am unaware of any enzyme/bacteria that would cause this to happen... What am I missing/not thinking of?

Thanks!

Jared Smith

Hello!

Here's one that has me puzzled. We thought to try performing an extended protien rest on a mash we were producing to make a kettle sour, as a means to not only promote the impact of  Protienase, Peptidase, and Beta-Glucanse, but to perhaps get a jump on lactic acid production via and LAB existing on the malt itself.

The pH effect was remarkable, of course. Mashed in at 120+/-, left overnight. pH fell from 5.24 to 3.6. We then raised the temp to 154 for a sacch rest, and then moved the mash to lauter. This is where the thing that is mystifying me happened. The mash was basically goo, and lauter was essentially impossible.

I am unaware of any enzyme/bacteria that would cause this to happen... What am I missing/not thinking of?

Thanks!

Jared Smith

Hello!

Here's one that has me puzzled. We thought to try performing an extended protien rest on a mash we were producing to make a kettle sour, as a means to not only promote the impact of  Protienase, Peptidase, and Beta-Glucanse, but to perhaps get a jump on lactic acid production via and LAB existing on the malt itself.

The pH effect was remarkable, of course. Mashed in at 120+/-, left overnight. pH fell from 5.24 to 3.6. We then raised the temp to 154 for a sacch rest, and then moved the mash to lauter. This is where the thing that is mystifying me happened. The mash was basically goo, and lauter was essentially impossible.

I am unaware of any enzyme/bacteria that would cause this to happen... What am I missing/not thinking of?

Thanks!

Jared Smith