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In Over My Head (Once Again)

Hello Everyone,

For my third AG batch, I am considering a Dry Stout recipe from “Brewing Classic Styles”. The recipe calls for a two-step mash, which I have not done before. The first step is at 120 degrees for 15 minutes, followed by a 60 minute rest at 150. My question is: how can this be best achieved with a cooler set up according to the Denny Conn method?

Thanks in advance for your consideration!

Do the first step with water in the 1qt/lb range, then add boiling water to hit the second rest temp.

Is there a lot of adjuncts in that recipe?
I like a step mash myself but that protein rest is not worth it almost always anymore.
Pull one big thick decoction and add it back slowly till you hit sacch temp.

[quote=“Scott Miller”]Is there a lot of adjuncts in that recipe?
I like a step mash myself but that protein rest is not worth it almost always anymore.
Pull one big thick decoction and add it back slowly till you hit sacch temp.[/quote]

He never has done a step mash how do you think he will fair doing a decoction.

I’m not a fan of the recipes from that book why don’t you brew this recipe from Jimal.

I’d put money on him.

Edit - I just kinda like pulling decoctions. Its more romantic than adding hot water.

Depending on your grain bill you may or may not need a protein rest. If you are using english pale malt you should just skip it. If you are using american brewers malt or oatmeal, a beta glucan rest may be beneficial. The temp boost usually comes from boiling water. Most brewing software will handle the temps and volumes for the steps and you can tell if your mash setup is big enough to handle the volume.

Right. If you have one of those big boy coolers it’s no sweat.
If not sure, figure your total water infusions before you run off as Qt/# and use the calculator at the bottom of the page to make sure it wont spill out.

Thanks for all of the responses, and thanks for the vote of confidence, Scott!

For the record, the grain bill for a 5 gallon recipe calls for:

7 lb Pale Malt (Maris Otter)
2 lb Flaked Barley
1 lb Black Barey (crushed “almost to dust”)

It’s very nearly the same recipe that Chuck was good enough to post.

So after reading the responses, I see that there is clearly more than one was to skin this cat. In thinking of the various ways to go about it, I had the following thoughts/questions:

  1. I now see that if I just skip the protein rest altogether, there should be no ill consequences.

  2. If I mashed in thick (1 qt./lb.) at 120 and then added enough boiling water to raise the temp. to 150, I see that the amount of additional water would make the mash quite thin – would this be a concern?

  3. The idea of a doing a decoction actually did cross my mind, but seemed like a technique that only the virtuoso brewers used. I googled around and found a decoction calculator that gave me the following numbers:

Pounds of grain: 10
Quarts of Water: 12.5 (@ 1.25 qt./lb.)
Mash Temp: 120
Target Temp: 150
Decoction Temp: 212

Decoction Volume: 9.8 pints (about 5 quarts)

If I decide to go all in and try a decoction, would I simply pull 5 quarts from the mash, heat it to boiling, and then add it back? I didn’t know if the grain to water ratio mattered when I pulled from the mash or if the temp. had to be raised at a specific rate. Also, I’ve read a lot about not letting the mash temp get to 170 for fear of extracting tannins – how does this square with bringing a portion of the mash to boiling?

One suggestion take that black barley and just sprinkle it over the mash about 10-15 minutes before mashout it will help with the bitterness that that grain gives you.

Or use the debittered black barley then add it 15 min before mashout.

I have done a lot of step mashes in my 48 qt cooler (5 gal) and go as thin as you need to, it will not make a difference. In my experience, the jump from 120 to 150 would not need a ton of boiling water. If you start thick there is not a lot of 120 degree water to try and hold it current temperature and the boiling water will win the fight so to speak.

In my opinion, you should move the rest temp to 131F instead of 120F. This will help with head retention but not go after the proteins. Mashing in at a lower temp does have the benefit of a better distribution of grain. At these lower temps the starch does not clump in doughballs so it is easier to stir in and get an even soak of the grain.

Also, I just made a stout and imho, a decoction sound like more overkill than the step mash! These beers are already heavy and malty. But there are many ways to do it.

With that grist bill, you absolutely don’t need the 120 rest.

Based on the recipe, I assume they intended this to be a beta glucan rest. Since the beer won’t need a protein rest, but might benefit from a beta glucan rest, I’d lower the temperature of the rest to 100-110°F for 15’ and start thick. You can even go as low as 0.75 qt/# or so, since leaving some dough balls won’t be a big deal at that point. The lower temperature will reduce the damage that might be done by a protein rest.

With well modified british malts too long of a protein rest will be detrimental to head retention. Adding dark roasted malts help lower Ph. So only move the roasted grain to the end if you have the Ph already taken care of.

A beta glucan rest can be helpful for poorly or un-modified grains like flaked adjuncts. A beta glucan rest can make the proteins and starches, bound by the glucan-rich cell walls, available in unmalted grains. In addition, a beta glucan rest will break down the gums that can lead to slow and stuck lauters in flaked grain-rich grain bills.

Skip the rest at 120 F. It won’t help, and could possibly hurt your beer. Wasted effort.

Thanks once again to Denny and to all who replied.

I’ll go ahead and omit the 15 minute rest at 120 – I almost always count it as a good day when less turns out to be more.

My experience is that a beta glucan rest is pointless for a grist like this. YMMV.

+1 on skipping it, just do your single infusion

Another vote here on skipping the rest. I’ve made that same beer multiple times without the rest. it’s the classic Guiness recipe.

And BTW, you can grind supermarket “pearl barley” and add it to your mash instead of paying for the flaked.

I don’t get the “black barely” part. I’d personally use Roasted Barley in a stout, not black patent.

As for the decoction, you’re doing a cheater decoction. Just pull the grain out with a SS kitchen strainer so most of the liquid stays in the mash. Stir and heat to boiling, then add back. You don’t need to cook it for 30 min like a lager decoction, and any of the arguable increase in maltiness will be lost in a stout anyway.

I also like mashing that beer at 155*.

The ß-glucan rest is one of those things that will be more or less useful to different brewers. If you tend to get middling efficiency or dance near the edge of a stuck sparge, the ß-glucan rest can be helpful with Oatmeal. It will be less useful to brewers without these problems and it will have no benefit to malted grains, which have already undergone ß-glucanase activity during malting.

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