Rest at 162 F?

[erykmynn]

I'm looking at a Lager recipe that calls for:

20 min rest @ 122
45 min rest @ 151
45 min rest @ 162 (or 161.2)

So far I've only done a couple of single-infusion ale recipes, but based on what I've read I can't figure the purpose of the 162 degree rest. It's not listed in my reference as a common rest, but I guess Alpha Amylase would still be active.

I wonder if it's necessary, or if I could uncomplicate things by doing two rests only and adjusting the saccrification rest some.

I'm using mostly a German Pilsner malt (7.5 pounds) and a half pound of carapils.

 

[cjmcfoot]

If it were my recipe, I would cut out the last rest, bump up the temp just a little like 154 on the sacc rest, and rest for 60min.
Do you batch sparge or fly sparge?

 

[erykmynn]

If it were my recipe, I would cut out the last rest, bump up the temp just a little like 154 on the sacc rest, and rest for 60min.
Do you batch sparge or fly sparge?

batch sparge

 

[cjmcfoot]

Hmmm, I don't know, that seems pretty close in temperature to a mash out 167F. This is too close in my opinion to breaking that alpha amylase phase, If someone is not diligent in constant calibration of their thermometer they run that risk. Or like my mash tun... the thermometer is low in the mash tun so the temp at the top of the grain bed is about 10 degrees warmer than the bottom with my 10gallon batches.
However with that said, the two other rests are long enough when it comes to highly modified malt, but you did mention pilsner malt, I think the diastatic power is lower with pilsner malt, right? That could be one of the reasons for the third higher temp rest.

 

[pjj2ba]

The last step is a dextrin step. That schedule looks pretty close to what I do, except the last step is too long, I'll do 10-20 min. I use 20 min. if my saccharification rest time is shorter, 10 min. if longer (like yours). The rest at 151 will give you most of your fermentable sugars. I'd actually push this down to 148-9. At the last step, beta-amylase doesn't work well, but alpha amylase does and will give you some longer chain unfermentable dextrins that can add body to the finished beer. I will use anywhere from 158-162 for the last step.

 

[jja]

+1 on pjj2ba's post. I find my multi-step mash at 145 and 162 to give a dry yet malty beer not matched by single temps or malt choice. 151/162 would be a bit maltier, so if you want to simplify, you can just try a single rest at 154 as cjmcfoot said.

 

[joety]

The last step is a dextrin step. That schedule looks pretty close to what I do, except the last step is too long, I'll do 10-20 min. I use 20 min. if my saccharification rest time is shorter, 10 min. if longer (like yours). The rest at 151 will give you most of your fermentable sugars. I'd actually push this down to 148-9. At the last step, beta-amylase doesn't work well, but alpha amylase does and will give you some longer chain unfermentable dextrins that can add body to the finished beer. I will use anywhere from 158-162 for the last step.

That only works if you aren't fully converted yet, correct? I don't think enzymes can piece the chains back together again to make them longer.

 

[pjj2ba]

That only works if you aren't fully converted yet, correct? I don't think enzymes can piece the chains back together again to make them longer.

Correct. If you hold the saccharification rest too long, then there will be no starch left for there to be any benefit to a dextrin rest. I keep my sacch. rests between 20-40 min. 20 for a malty helles, 40 for a crisp lager.

 

[StAnthonyB]

I'm looking at a Lager recipe that calls for:

20 min rest @ 122
45 min rest @ 151
45 min rest @ 162 (or 161.2)

So far I've only done a couple of single-infusion ale recipes, but based on what I've read I can't figure the purpose of the 162 degree rest. It's not listed in my reference as a common rest, but I guess Alpha Amylase would still be active.

I wonder if it's necessary, or if I could uncomplicate things by doing two rests only and adjusting the saccrification rest some.

I'm using mostly a German Pilsner malt (7.5 pounds) and a half pound of carapils.

Looks like something similar to a Hochkurz mash... except there the steps are 40min@142F, 40min@158F, and 20min@167F.

Ask Kaiser about this one.

 

[SpanishCastleAle]

Looks like something similar to a Hochkurz mash... except there the steps are 40min@142F, 40min@158F, and 20min@167F.

Ask Kaiser about this one.

That's what I was thinking.

That schedule looks pretty close to what I do, except the last step is too long,

In Kaiser's write-up on the Hockhurz mash schedule he says that some (Narziss/Fix at least) report better head retention and body with an extended rest @ 158-162. Here's the part from his Decoction mashing article where he talks about this topic:

This version of a double decoction mash is known as Hochkurz Mash in German brewing [Narziss, 2005]. It uses a 2 temperature saccharification rest. The first decoction is used to get from the 1st saccharification rest (maltose rest) to the 2nd saccharification rest (dextrinization rest) and the 2nd decoction is used for mash-out. The dough-in can happen with the protein rest, an intermediate rest or the maltose rest. Hochkurz refers to the fact that these mashes dough in high (hoch) and are short (kurz).

To optimize the use of the beta amylase and produce a wort with high levels of maltose, German brewers often use a 2 step saccharification scheme. With today's well modified malts the protein rest is generally skipped. The first rest, usually held at 140 - 146 *F (60 - 63 *C) gives the beta amylase time to convert the glucose chains (large dextrins) into maltose. At this temperature there is already sufficient alpha amylase activity available to provide enough glucose chain ends for the beta amylase. This is needed because the beta amylase can only clip maltose from the non reducing end of a glucose chain. Due to the lower temperature, the beta amylase will be active for a longer time as it would in a single saccharification rest held at higher temperatures. To reduce and eventually terminate the beta amylase activity and to ensure that all starch in the wort has been converted (especially the small starch granules which have a higher gelatinization temperature), a dextrinization rest is held at 158 - 162 *F (70 - 72 *C). At this temperature the beta amylase is quickly deactivated and only the alpha amylase works on the starches. The rest is held until the mash is iodine negative (no starch or long dextrines in the wort). Narziss [Narziss, 2005] and Fix [Fix, 1999] suggest, that a rest at 158 - 162 *F (70 - 72 *C) benefits head retention and body of the beer though glycoproteides that are extracted from the malt but not degraded by enzymatic activity. Because of that Narziss suggests holding this rest up to 60 min. After that rest a mash-out is performed at 167-173F (75-78 C). The temperature should not be higher as this would deactivate all the alpha amylase activity and some alpha amylase activity is still needed during lautering to convert any rogue starches, that might be liberated during sparging, on their way to the kettle.

EDIT: Oh yea, I often do Hockhurz infusion mashes (see Kaiser's Infusion Mashing article) and just like pjj2ba mentioned, I'll sacc rest about 40-45 min. for a fermentable wort and 15-20 min for a less fermentable wort.

 

[erykmynn]

This is great guys! I just wanted to confirm there is some purpose to it, so I think I'll do the recipe as-is for now, then if I want to simplify the schedule later I'll have a baseline.

 

[erykmynn]

So I followed this schedule this weekend (20 at 122, 45 at 151, 45 at 162), and ended up having to add 15 minutes to the last rest before the iodine test came out correctly.

Though that may have been because I botched one of the infusions, I'm not exactly sure how or when, but when trying to move between 151 and 162 I kept adding water to no avail and eventually just stirred the darn thing with the heatstick.

All in all, efficiency seemed to come out OK, gotta pour over the notes now. Needless to say, the third rest wouldn't have wrapped up in 20 min. Will be a relief to do single-infusion next time.

My prediction is that it will either come out about right, and I just had the wrong volume (but right temp) at some point or not hot enough infusion water ... or it's going to come out way too "dextriney" (dextrinous?) if I messed up the middle rest...