Will Decoction Steps Create TOO Fermentable Wort?

[JoppaFarms]

I'm considering trying a decoction mash on an American dark lager that I'm brewing for the first time. The recipe I tweaked used decoction mash. I've never done a decoction, and from my (limited) knowledge of the process, it comes from "the good ol' days" when malts were under modified and needed a little extra help in the mash to get full conversion. I've also heard it can reduce the effects of protein in the beer with the proper steps in the process.

I would like a clear beer, but this is a dark lager (~22SRM so not THAT dark) so clearer is better, but my question is this...

Since modern malts are higher modified than the past, will it cause me to create a wort that is highly fermentable if my steps are 122F (35m), 147F (20m) and 156F (20m), and mash out at 168F (10m) (like the recipe says)? 147 seems like a temperature that could cause my wort to be more fermentable than desired, leaving me with a lower FG in the end.

Is this not the case with decoction because of the 122F and 156F steps? Thanks in advance for any pointers on this one!

 

[Yooper]

I'm considering trying a decoction mash on an American dark lager that I'm brewing for the first time. The recipe I tweaked used decoction mash. I've never done a decoction, and from my (limited) knowledge of the process, it comes from "the good ol' days" when malts were under modified and needed a little extra help in the mash to get full conversion. I've also heard it can reduce the effects of protein in the beer with the proper steps in the process.

I would like a clear beer, but this is a dark lager (~22SRM so not THAT dark) so clearer is better, but my question is this...

Since modern malts are higher modified than the past, will it cause me to create a wort that is highly fermentable if my steps are 122F (35m), 147F (20m) and 156F (20m), and mash out at 168F (10m) (like the recipe says)? 147 seems like a temperature that could cause my wort to be more fermentable than desired, leaving me with a lower FG in the end.

Is this not the case with decoction because of the 122F and 156F steps? Thanks in advance for any pointers on this one!

Maybe- but you definitely do NOT want to hold at 122 for 35 minutes- that is too long of a protein rest for today's well modified malts. I'd skip the protein rest, or just warmer for a shorter period of time. I'd go to 131-133, only long enough to pull a decoction to avoid excessive protein degradation, or skip the protein rest entirely.

I'd suggest a hochkurz double decoction for a better schedule for your goals. Check out this page on braukaiser.com: http://braukaiser.com/wiki/index.php?title=Decoction_Mashing and scroll down a bit for an explanation. In short, doing the maltose rest in the 140s and then a dextrinization rest in the high 150s and making the maltose rest fairly short should do exactly what you seem to want.

 

[TheZymurgist]

Maybe- but you definitely do NOT want to hold at 122 for 35 minutes- that is too long of a protein rest for today's well modified malts. I'd skip the protein rest, or just warmer for a shorter period of time. I'd go to 131-133, only long enough to pull a decoction to avoid excessive protein degradation, or skip the protein rest entirely.

I'd suggest a hochkurz double decoction for a better schedule for your goals. Check out this page on braukaiser.com: http://braukaiser.com/wiki/index.php?title=Decoction_Mashing and scroll down a bit for an explanation. In short, doing the maltose rest in the 140s and then a dextrinization rest in the high 150s and making the maltose rest fairly short should do exactly what you seem to want.

I agree. My understanding is that a protein rest is only necessary when using a huge amount of rye or wheat (and it is definitely necessary with the rye, personal experience...)

 

[Roundhouse]

I don't know what base malt you are using but if it's American 2 row you'll destroy your head retention with that protein rest. I'd dough in at sacc rest temp. If you insist on doing a decoction with a highly modified grain, do so as a single step to raise the temperature to mash out temp and even then wait 45 minutes to an hour to pull the decoction to make sure conversion is essentially done. Keep the decoction boil fairly short.

 

[TheZymurgist]

I don't know what base malt you are using but if it's American 2 row you'll destroy your head retention with that protein rest.

Most of what I've seen has said this is largely a myth. I would agree, in my (very) limited experience. I've done a few decoctions and haven't had any issues, and I've had a good number of decocted beers in my club that had no issues with head retention.

 

[SnakeRidge]

I do the rest at 131-133 for 20-30 minutes while I boil a decoction to get up to 154ish when I do a roggenbier or hefeweizen. No problems there with head retention at all.

 

[Roundhouse]

Most of what I've seen has said this is largely a myth. I would agree, in my (very) limited experience. I've done a few decoctions and haven't had any issues, and I've had a good number of decocted beers in my club that had no issues with head retention.

It's hardly a myth. I messed up my Oktoberfest decoction schedule and rested at 122 for 20 minutes before pulling a decoction. That was the wrong time to pull it. Be the time I added it back after boiling to raise the temp to 144, the main mash sat at that temperature for over 50 minutes. I was supposed to infuse to 144 and pull the decoction for a rise to 158, which I still did. That beer while tasty, had no head retention at all. There was no pilsner malt so what I had was pretty well modified. I should have done a 15 minute rest at 131 before infusing to 148.

 

[JoppaFarms]

Thanks a bunch for the link and the info gents. I suppose I should have included the grain bill, maybe that would help:

6 lbs German Pilsen
1.5 lbs Flaked Corn
1 lb Munich
3/4 lb Crystal 60
3/4 lb Roasted Barley
1 oz Hallertau
WLP833 German Bock Lager

It's a pseudo-clone of Shiner Bock that I found and tweaked a little bit. I want it in the ballpark with Shiner, which is more of an American dark lager than a true Bock. I'm not sure if Shiner does a decoction after doing a little research (doubtful actually that they do) so I may skip it entirely. It was on the recipe that I modified and I figured I would try it, just for fun. Looks like I'm not quite ready for it, as I don't fully understand the procedure. I'll see if I can do some more research on it. Thanks a gain guys.

 

[TheZymurgist]

It's hardly a myth. I messed up my Oktoberfest decoction schedule and rested at 122 for 20 minutes before pulling a decoction. That was the wrong time to pull it. Be the time I added it back after boiling to raise the temp to 144, the main mash sat at that temperature for over 50 minutes. I was supposed to infuse to 144 and pull the decoction for a rise to 158, which I still did. That beer while tasty, had no head retention at all. There was no pilsner malt so what I had was pretty well modified. I should have done a 15 minute rest at 131 before infusing to 148.

Could it be said that the difference here is that under a properly executed decoction, head retention isn't likely to be an issue?

 

[SnakeRidge]

Thanks a bunch for the link and the info gents. I suppose I should have included the grain bill, maybe that would help:

6 lbs German Pilsen
1.5 lbs Flaked Corn
1 lb Munich
3/4 lb Crystal 60
3/4 lb Roasted Barley
1 oz Hallertau
WLP833 German Bock Lager

It's a pseudo-clone of Shiner Bock that I found and tweaked a little bit. I want it in the ballpark with Shiner, which is more of an American dark lager than a true Bock. I'm not sure if Shiner does a decoction after doing a little research (doubtful actually that they do) so I may skip it entirely. It was on the recipe that I modified and I figured I would try it, just for fun. Looks like I'm not quite ready for it, as I don't fully understand the procedure. I'll see if I can do some more research on it. Thanks a gain guys.

That looks like a good recipe for Shiner. I'd skip the decoction too if it were me. For what it's worth, here is my Shiner clone that passes the test of my wife's Round Rock and Buda Texas clan:

5.75 gallon batch at 78% efficiency

3.5# 6-Row
3.5# Munich
2.0# Flaked Corn (I use grits)
8oz Caramel 40
4oz Carafa Special III (dehusked)

Single addition of Magnum at 60' for 15 IBU's.

It's not perfectly spot on, but everyone who's tried it likes it as well or better than the original. I call it my Shiney! Bock for you Firefly fans out there.

 

[D-Train]

Could it be said that the difference here is that under a properly executed decoction, head retention isn't likely to be an issue?

I've done two decoctions. I don't think the first spent much time at a protein rest but I'd have to check my notes. The second used an infusion to go from protein rest to sacchirification knowing that I wanted it to be short, which it was, and I went high on the protein rest temp which appeared to be the prevailing wisdom so as to retain head retention. I was disappointed in the head retention of both. I think I'll skip it on the next one.

 

[Roundhouse]

Could it be said that the difference here is that under a properly executed decoction, head retention isn't likely to be an issue?

I do decoctions all the time. I messed up on that one. When I say no head retention, I mean NO head retention! Even properly carbonated I had a hard time building up a head on it while pouring and what was there was gone in seconds.

The guideline that I follow for a protein rest is based on the SNR of the base grains.
SNR < 36 rest in the 122°-125° range. No longer than 20 minutes.
SNR 37-40 rest in the 130°-133° range. No longer than 20 minutes.
SNR >40. No protein rest.

When I've followed that as a guide, the results have always been good. The one time I went outside of it, in this case 2-1/2 times longer, head retention was destroyed. Could it have possibly been due to something else? Potentially. However, the evidence overwhelmingly supports too long of a protein rest. A protein rest on American 2 row, even a short one, could hurt head retention. It isn't always necessary. Some would argue it's never absolutely necessary and that may be true. When it is beneficial there are guidelines that should be adhered to such as the above.

 

[TheZymurgist]

I do decoctions all the time. I messed up on that one. When I say no head retention, I mean NO head retention! Even properly carbonated I had a hard time building up a head on it while pouring and what was there was gone in seconds.

The guideline that I follow for a protein rest is based on the SNR of the base grains.
SNR < 36 rest in the 122°-125° range. No longer than 20 minutes.
SNR 37-40 rest in the 130°-133° range. No longer than 20 minutes.
SNR >40. No protein rest.

When I've followed that as a guide, the results have always been good. The one time I went outside of it, in this case 2-1/2 times longer, head retention was destroyed. Could it have possibly been due to something else? Potentially. However, the evidence overwhelmingly supports too long of a protein rest. A protein rest on American 2 row, even a short one, could hurt head retention. It isn't always necessary. Some would argue it's never absolutely necessary and that may be true. When it is beneficial there are guidelines that should be adhered to such as the above.

I think we're trying to make the same point, that, if done properly, a decoction shouldn't hurt head retention.

 

[Roundhouse]

Properly is the key. Improperly can absolutely hurt it. That includes not only adding a protein rest to grains that are well modified but also having too long of a rest time. Too long of a protein rest, even on lower modified grains, can absolutely hurt head retention.

 

[JoppaFarms]

That looks like a good recipe for Shiner. I'd skip the decoction too if it were me. For what it's worth, here is my Shiner clone that passes the test of my wife's Round Rock and Buda Texas clan:

5.75 gallon batch at 78% efficiency

3.5# 6-Row
3.5# Munich
2.0# Flaked Corn (I use grits)
8oz Caramel 40
4oz Carafa Special III (dehusked)

Single addition of Magnum at 60' for 15 IBU's.

It's not perfectly spot on, but everyone who's tried it likes it as well or better than the original. I call it my Shiney! Bock for you Firefly fans out there.

That sounds pretty good too. I'm concerned that I didn't give it enough munich, but since it's "technically" an American lager, I'm hoping that the ratio will still give it that medium malty finish that I'm looking for. Got any pictures of your version, what does the SRM end at?

 

[SnakeRidge]

That sounds pretty good too. I'm concerned that I didn't give it enough munich, but since it's "technically" an American lager, I'm hoping that the ratio will still give it that medium malty finish that I'm looking for. Got any pictures of your version, what does the SRM end at?

No pictures that I can find. They used to give SRM on the Spoetzl website but they've changed it. I copied it down back when I was getting my recipe together, though:
4.4% ABV
13 IBU
18 SRM

I shoot for that 18 SRM in Beersmith. I've read that Spoetzl uses Sinamar in lieu of roasted malt, but I've never messed around with it.