Author Topic: Mash Temps and Water Profile - Bock  (Read 2762 times)

Offline mtnandy

  • Cellarman
  • **
  • Posts: 32
  • Houston, TX
    • View Profile
Mash Temps and Water Profile - Bock
« on: January 12, 2011, 08:36:09 PM »
I'm planning on making a traditional bock this weekend. I'll be trying a decoction for the first time  :) What temps should I use for each step? I am thinking a triple decoction is the way to go, with steps of 97, 122, and 154. Am I in the ballpark? My recipe is 100% Munich II.

Also, my water profile is:
42.1 Ca
8.2 Mg
85 Na
41 SO4
100 Cl
195 HCO3
7.5 PH

Is this profile suitable for a bock? I know the high carbonate is good for the style, and I've never really concerned myself with my water profile, so I just want to make sure it's acceptable...

Thanks!

Offline Kaiser

  • Global Moderator
  • Senior Brewmaster
  • *****
  • Posts: 1797
  • Imperial Brewing Geek
    • View Profile
    • braukaiser.com
Re: Mash Temps and Water Profile - Bock
« Reply #1 on: January 12, 2011, 10:25:51 PM »
I think you'll be fine. The residual alkalinity is ~100 ppm as CaCO3 which will work with a all 100% Munich Malt grist.

The decoction steps seem fine too.

Kai

Offline mabrungard

  • Senior Brewmaster
  • ******
  • Posts: 1461
    • View Profile
    • Bru'n Water
Re: Mash Temps and Water Profile - Bock
« Reply #2 on: January 13, 2011, 07:15:56 AM »
I'm going to have to differ with Kai on this one.  Although alkalinity is needed to moderate mash pH when dealing with darker grists, it needs to be within limits.  The alkalinity of this water is too high for a beer that will end up around a color or 11 to 12 SRM.  I calculate that about 0.4 to 0.5 ml/gal of 88% lactic acid should be added to the mash water to bring the alkalinity more in line with successful mash pH. 

The elevated sodium and chloride are troubling, but not to the point of distraction.  This water appears to be from a water system that softens their water with ion-exchange.  The water hardness is reduced to about the level that most users find acceptable (140ppm).  My municipal water system and many others in the midwest use this type of softening on their extremely hard water.  This brewer is fortunate.  My tap water can have up to 250 ppm sodium and it still has significant hardness.

Another option would be to add gypsum to decrease the residual alkalinity, but the sulfate and chloride concentrations are already too high.  So, nix that option.   

The third option is to dilute with RO or distilled water.  It appears that 50% dilution would work.  The calcium content would be a little low and about 0.1 g gypsum and 0.2 g CaCl would be neeeded for each gallon of mash water.   No lactic acid would be required for the mash water if dilution is used.

Its a tough water to start with.

Martin B
Carmel, IN

BJCP National
Foam Blowers of Indiana (FBI)

Brewing Water Information at:
https://sites.google.com/site/brunwater/

Like Bru'n Water on Facebook for occasional discussions on brewing water and Bru'n Water
https://www.facebook.com/pages/Brun-Water/464551136933908

Offline Kaiser

  • Global Moderator
  • Senior Brewmaster
  • *****
  • Posts: 1797
  • Imperial Brewing Geek
    • View Profile
    • braukaiser.com
Re: Mash Temps and Water Profile - Bock
« Reply #3 on: January 13, 2011, 08:43:36 AM »
My reasoning was that the Munich malt is likely to have a distilled water mash pH of 5.3-5.4. And a water with ~100 ppm RA in a 2 qt/lb mash will bump this pH by about 0.13 which puts the mash pH into the 5.45 – 5.55 range. In a 1.5 qt/lb mash the pH rise will be lower.

I did miss the low Ca, which I don’t think will be too much of a problem, and the high Na. Adding some gypsum and/or calcium chloride is a good idea though.

In my calculations, 0.4-0.5 ml 88% LA would eliminate all alkalinity which seems to be a bit much for a 100% Munich malt beer.

Kai

Offline tomsawyer

  • Senior Brewmaster
  • ******
  • Posts: 1694
    • View Profile
Re: Mash Temps and Water Profile - Bock
« Reply #4 on: January 13, 2011, 08:47:38 AM »
Wouldn't you want individual alpha and beta rests in your schedule?  I figure 122F is a protein rest, I don't even know what a 97F rest is there for unless its just doughing in.  I'd be inclined to go 122F, 146F and 156F.  But I'm no decoction expert, just throwing this out for discussion.

Also, will Munich II self-convert?

I'd use CaCl2 for the malt flavor profile.  And I'm using more lactic than that for acid adjustments and don't taste anything.
Lennie
Hannibal, MO

Offline hamiltont

  • Brewmaster
  • *****
  • Posts: 987
  • Location: Somewhere in the Middle of Nebraska
    • View Profile
Re: Mash Temps and Water Profile - Bock
« Reply #5 on: January 13, 2011, 08:53:30 AM »
I recently did a Dopplebock/Bock partigyle with a 20 minute acid rest @ 101F. The PH was @ 5.2 at the end of it. No dark malts & a total of ~21 gallons of well water with no adjustments.  I think the acid rest is key. I could have adjusted the water & skipped the acid rest but I was attempting to do it "old school". The first decoction was stepped to 162F for 30 minutes & boiled for 40 minutes then added back for 150F rest for 45 minutes. Then a thin decoction was pulled & boiled through the hot break & added for the mashout. They're both lagering now and initial samples are tasting good.  Cheers!!

Malt:
19.5 lb. Munich
7 lb. Pilsner
6 lb. Vienna
Carafa II was added for color right after the 1st decoction was pulled.


water:
pH 7.6
Total Dissolved Solids (TDS) Est 274
Electrical Conductivity, mmho/cm 0.46
Cations / Anions, me/L 5.2 / 5.1

measured in ppm
Sodium, Na 7
Potassium, K 5
Calcium, Ca 77
Magnesium, Mg 10
Total Hardness, CaCO3 234
Nitrate, NO3-N 1.0
Sulfate, SO4-S 3
Chloride, Cl 5
Carbonate, CO3 < 1
Bicarbonate, HCO3 287
Total Alkalinity, CaCO3 236
If Homebrew & BBQ aren't the answer, then you're askin' the wrong questions... Cheers!!!

Offline Kaiser

  • Global Moderator
  • Senior Brewmaster
  • *****
  • Posts: 1797
  • Imperial Brewing Geek
    • View Profile
    • braukaiser.com
Re: Mash Temps and Water Profile - Bock
« Reply #6 on: January 13, 2011, 09:03:58 AM »
Wouldn't you want individual alpha and beta rests in your schedule? 
You don’t have to.  Traditionally there is only one sacc rest in a triple decoction.

Quote
Also, will Munich II self-convert?

Yes, but it takes a bit longer. Using about 10-15% Pilsner malt in the grist as insurance would mitigate problems. It also makes sense to keep the mash pH closer to 5.6 which helps the a-amylase.

Kai

Offline mabrungard

  • Senior Brewmaster
  • ******
  • Posts: 1461
    • View Profile
    • Bru'n Water
Re: Mash Temps and Water Profile - Bock
« Reply #7 on: January 13, 2011, 09:30:19 AM »

In my calculations, 0.4-0.5 ml 88% LA would eliminate all alkalinity which seems to be a bit much for a 100% Munich malt beer.

Kai


My calculations show that for the 161 ppm of Alkalinity that the 195 ppm HCO3 provides, the amount of 88% lactic acid required to bring the pH to 4.3 (definition of zero alkalinity) would be 1.38 mL per gallon of water.   That is a lot of alkalinity and the amount of acid per gallon is large too.  Those numbers are not a surprise to me.

Adding 0.4 ml/gal lactic brings the alkalinity to about 100 ppm and adding 0.5 ml/gal lactic reduces it to about 80 ppm. 

Are you sure your calculation is correct?
Martin B
Carmel, IN

BJCP National
Foam Blowers of Indiana (FBI)

Brewing Water Information at:
https://sites.google.com/site/brunwater/

Like Bru'n Water on Facebook for occasional discussions on brewing water and Bru'n Water
https://www.facebook.com/pages/Brun-Water/464551136933908

Offline Kaiser

  • Global Moderator
  • Senior Brewmaster
  • *****
  • Posts: 1797
  • Imperial Brewing Geek
    • View Profile
    • braukaiser.com
Re: Mash Temps and Water Profile - Bock
« Reply #8 on: January 13, 2011, 10:21:16 AM »
Martin,

This is another disconnect between theory and practice. I was using my water calculator to determine the acid it takes to reduce the residual alkalinity to 0 and that calculator gives lactic acid twice the power than it should have.

When adjusting mash pH with acids I repeatedly fund that it takes about 30 mEq for a drop of 1 pH unit for every kg of grist.

When I calculate this for  raising mash pH though alkalinity or baking soda I get an effectiveness of ~60 mEq/(kg*pH) or even less (higher numbers mean less effective). This doesn’t seem to make sense to me either but I keep seeing this. I have repeated experiments many times and doubt that my calculations are wrong at some point. The recent findings about the effect of time make me want to go back to some of the experiments I conducted.

But regardless of this calculation I don’t think there is a need for alkalinity reduction in this water when used with a 100% Munich malt grist.

Kai


Offline mtnandy

  • Cellarman
  • **
  • Posts: 32
  • Houston, TX
    • View Profile
Re: Mash Temps and Water Profile - Bock
« Reply #9 on: January 13, 2011, 10:29:33 AM »
Thanks for the help guys! For what it's worth, my water report lists alkalinity as 160. I'm trying to slowly learn about the relationships among water profiles, mash temps, and different grain types. It's a lot of information to remember  ;) For mashing, I'm pretty much going by the triple decoction schedule on Kai's decoction wiki page.

Offline mabrungard

  • Senior Brewmaster
  • ******
  • Posts: 1461
    • View Profile
    • Bru'n Water
Re: Mash Temps and Water Profile - Bock
« Reply #10 on: January 14, 2011, 11:40:07 AM »
Kai,

I agree that the mash's ability to buffer pH change is substantial, but I do not recommend adding acid to the mash in order to adjust the alkalinity of the water that will be used for the mash.  

The goal is to adjust the water's alkalinity to a prescribed level prior to mashing.  That way, the only buffer the acid is countering is the bicarbonate alkalinity.  The observed pH effect that you mention would not come in to play then.  The goal is to remove that excessive water alkalinity before the buffering offered by the grist is called in to play.  

Without the minor acidification I called out above, this mash pH is not likely to fall into the preferred range.   This is still a fairly light colored malt and the alkalinity is high.
« Last Edit: January 14, 2011, 11:47:01 AM by mabrungard »
Martin B
Carmel, IN

BJCP National
Foam Blowers of Indiana (FBI)

Brewing Water Information at:
https://sites.google.com/site/brunwater/

Like Bru'n Water on Facebook for occasional discussions on brewing water and Bru'n Water
https://www.facebook.com/pages/Brun-Water/464551136933908

Offline Kaiser

  • Global Moderator
  • Senior Brewmaster
  • *****
  • Posts: 1797
  • Imperial Brewing Geek
    • View Profile
    • braukaiser.com
Re: Mash Temps and Water Profile - Bock
« Reply #11 on: January 14, 2011, 01:28:50 PM »
This may lead to an interesting discussion.

I agree that the mash's ability to buffer pH change is substantial, but I do not recommend adding acid to the mash in order to adjust the alkalinity of the water that will be used for the mash. 

What’s the difference?  The alkalinity in the water pushed the mash pH up and the acid will bring it back down. If I add the acid to the water first it reaches an equilibrium with the alkalinity in the water. If there was more acid than (residual) alkalinity the water will pull the pH down and if there was more (residual) alkalinity than acid the water will push the pH up.

Quote
The goal is to adjust the water's alkalinity to a prescribed level prior to mashing.  That way, the only buffer the acid is countering is the bicarbonate alkalinity.  The observed pH effect that you mention would not come in to play then.  The goal is to remove that excessive water alkalinity before the buffering offered by the grist is called in to play. 

While I still see some oddities that I cannot explain I do think that the order in which, water acid and malt are mixed should not matter for the resulting pH. If I were to take 3 buffer solutions and mix them in every possible order the resulting pH should be the same. Or is there some chemical mechanism that I’m missing?

Quote
Without the minor acidification I called out above, this mash pH is not likely to fall into the preferred range.   This is still a fairly light colored malt and the alkalinity is high.

I’m taking this from my own experience. I expect the Munich II to have a distilled water pH of 5.3-5.4 and the alkalinity in the water will only raise the pH by ~0.1 – 0.2. This puts the resulting pH in the 5.40 – 5.6 range which is a good range for this beer. Cutting the alkalinity in half would keep the pH a bit lower which I don’t expect to be a problem either.

Kai

Offline malzig

  • Brewer
  • ****
  • Posts: 466
    • View Profile
Re: Mash Temps and Water Profile - Bock
« Reply #12 on: January 15, 2011, 11:58:40 AM »
This is another disconnect between theory and practice. I was using my water calculator to determine the acid it takes to reduce the residual alkalinity to 0 and that calculator gives lactic acid twice the power than it should have.

When adjusting mash pH with acids I repeatedly fund that it takes about 30 mEq for a drop of 1 pH unit for every kg of grist.

When I calculate this for  raising mash pH though alkalinity or baking soda I get an effectiveness of ~60 mEq/(kg*pH) or even less (higher numbers mean less effective). This doesn’t seem to make sense to me either but I keep seeing this.
It does seem to me that, in a complex buffered system like a mash, that the empirical measures trump the theoretical.
Are you taking into account the buffering capacity of the malt?  Wouldn't that explain why it takes more acid or base than expected to change the pH?  (I have to admit that I haven't taken the time to understand the math in this kind of chemistry.)

Offline mabrungard

  • Senior Brewmaster
  • ******
  • Posts: 1461
    • View Profile
    • Bru'n Water
Re: Mash Temps and Water Profile - Bock
« Reply #13 on: January 15, 2011, 01:57:10 PM »
This is another disconnect between theory and practice. I was using my water calculator to determine the acid it takes to reduce the residual alkalinity to 0 and that calculator gives lactic acid twice the power than it should have.

When adjusting mash pH with acids I repeatedly fund that it takes about 30 mEq for a drop of 1 pH unit for every kg of grist.

When I calculate this for  raising mash pH though alkalinity or baking soda I get an effectiveness of ~60 mEq/(kg*pH) or even less (higher numbers mean less effective). This doesn’t seem to make sense to me either but I keep seeing this.
It does seem to me that, in a complex buffered system like a mash, that the empirical measures trump the theoretical.
Are you taking into account the buffering capacity of the malt?  Wouldn't that explain why it takes more acid or base than expected to change the pH?  (I have to admit that I haven't taken the time to understand the math in this kind of chemistry.)

That is exactly why I recommend not adding acid that is intended to reduce mash water alkalinity directly to the mash.  It is consumed by the mash buffers instead of directly neutralizing the bicarbonate.  The action of the mash buffers are complex and it doesn't make sense to muddle the desired removal of bicarbonate with that action.  I differ with Kai on this point for this reason.  Given Kai's very salient evidence of the confounding action of these malt buffers, I don't see why he can't see it also.

Add acid to the water first and then add the grain.
« Last Edit: January 15, 2011, 02:07:29 PM by mabrungard »
Martin B
Carmel, IN

BJCP National
Foam Blowers of Indiana (FBI)

Brewing Water Information at:
https://sites.google.com/site/brunwater/

Like Bru'n Water on Facebook for occasional discussions on brewing water and Bru'n Water
https://www.facebook.com/pages/Brun-Water/464551136933908

Offline Kaiser

  • Global Moderator
  • Senior Brewmaster
  • *****
  • Posts: 1797
  • Imperial Brewing Geek
    • View Profile
    • braukaiser.com
Re: Mash Temps and Water Profile - Bock
« Reply #14 on: January 15, 2011, 09:24:32 PM »
I'll have to run some experiments on this. If the order in which the buffers are brought together truly matters I'll have to account for that. And it would be nice to find a scientific explanation why that is and why I can't just calculate the pH change like I would when I mix simpler buffers.

So far this aspect has been neglected in the way (home) brewers have been thinking about water adjustments.

Kai