mash schedule question

[brewmadness]

I'm going to brew an Irish extra stout based on a recipe from BYO magazine. The recipe calls for 8 lbs. golden promise, 2 lbs flaked barley, 8 oz. torrified wheat, 1.75 lbs chocolate malt and 8 oz. brown malt. The mash schedules says to to rest the golden promise, flaked barley and torrified wheat at 147 for 60 minutes, raise temp to 155 and hold for 30 minutes then raise the temp to 168, add the chocolate and brown malts and recirculate for 20 minutes before fly sparging. Here's my question. My grains have all been milled together with the exception of the flaked barley, so not mashing the dark malts for the entire mash time is not possible. Should I (a) follow the prescribed mash schedule with all grains in the recipe, or (b) just do a single infusion mash at say 154 degrees for an hour and call it good? I typically batch sparge, and my equipment doesn't allow me to recirculate. So if I do just batch sparge on single infusion as stated, how far off from the intent of the original recipe will the beer end up?

 

[McKnuckle]

The initial low mash temp is an attempt to produce more fermentable sugars, which will dry the beer out more, typical of an Irish stout. The higher mash step will produce more dextrins and contribute to the body of the finished beer. Both steps together will increase your overall extraction vs. a single infusion mash. That's why the recipe author crafted it this way. Is it essential? No, but you'll be compromising the author's intent a little bit.

The late added dark malts is an attempt to minimize harsh roasted flavors, and also it may have something to do with the author's preferred brewing water and mash pH. Don't worry about that part. I have an Irish stout on tap right now, 10% roasted grains, where everything was mashed together and it's smooth as can be. I did single infusion at 152º, but my OG was only 1.045. No "extra" in my version - that makes a difference in my mash temp choice.

 

[Lefou]

I ask my brew shop to pack all my unground grain in separate bags.
This keeps my Pilsner malt and higher diastatic wheat apart from the crystals and darker roasts should I decide to pull a decocted portion and re-add later before boiling.
For my "German" wheat beers, part of the mash goes in for the single infusion, the other portion gets put in for a ferulic acid rest, then removed for a quick boil. The boiled portion is then re-added to the mash, stirred, rested for 15 minutes, then drained for the boil.
For my upcoming Helles, I'm throwing the Pilsner and Vienna into a single infusion mash at around 152-155F.

There are loads of methods. I'd like to try a few and see what works for me. Part of the fun is changing things around to see what results.

 

[brewmadness]

McKnuckle - your explanation makes complete sense. Thanks. I think I will try the step mash with the grains all together. This time, and maybe try it again separating the dark malts as stated and see if I can tell the difference. Either way I will end up with beer!

 

[RM-MN]

There are a lot of variables in brewing and strictly following someone's recipe does not necessarily get you the exact results that they get. One of the variables is the crush of the grain. When you add grains to the water that is at strike temp the grains begin to absorb the water which gelatinizes the starches and activates the enzymes that convert the starch to sugar. The two enzymes we are mostly interested in are alpha and beta amylase. Both of these are temperature sensitive and become denatured with time and temp. Beta amylase is responsible for creating the fermentable sugars while alpha amylase creates dextrines (very much simplified for ease of explanation). Both work through a range of temperature and are eventually denatured by the same temps that activate them. Since beta amylase is activated and denatured at the lower temperature your initial mash temp is to get its activity and raising the temp will denature it quicker, leaving just the alpha amylase functioning. However, all of this depends a great deal on the crush of the grain. If your grains are crushed much finer, the starches are gelatinized quickly and the enzymes do their work and are denatured. That may all happen within the 60 minute mash and then the extra 30 minutes at the 155 temp isn't really doing much for you. Then too the 20 minutes of mashout temps that are to denature the enzymes may be a moot point if the enzymes are already denatured.

Since you have no information or knowledge of the crush that the recipe's author used, following it exactly may or may not get you the same results. You also may approximate the recipe by doing a single infusion mash at a temperature that is a compromise between the two temps the author specified and doing a double batch sparge.

 

[sky4meplease]

I'm going to brew an Irish extra stout based on a recipe from BYO magazine. The recipe calls for 8 lbs. golden promise, 2 lbs flaked barley, 8 oz. torrified wheat, 1.75 lbs chocolate malt and 8 oz. brown malt. The mash schedules says to to rest the golden promise, flaked barley and torrified wheat at 147 for 60 minutes, raise temp to 155 and hold for 30 minutes then raise the temp to 168, add the chocolate and brown malts and recirculate for 20 minutes before fly sparging. Here's my question. My grains have all been milled together with the exception of the flaked barley, so not mashing the dark malts for the entire mash time is not possible. Should I (a) follow the prescribed mash schedule with all grains in the recipe, or (b) just do a single infusion mash at say 154 degrees for an hour and call it good? I typically batch sparge, and my equipment doesn't allow me to recirculate. So if I do just batch sparge on single infusion as stated, how far off from the intent of the original recipe will the beer end up?

Are you sure the chocolate and brown malts don't get added at 155 degrees for 30 minutes then raise to 168 for 20 minutes?

Either way it sounds like your doing a single infusion on this one.
I would Mash it at 147-148 for 60 minutes and call it good.
If your using soft or R/O water it may be worth visiting a water calculator. That dark grain may drive your PH into the basement.

 

[dmtaylor]

150 F for an hour and you're done. I doubt there is true value in dicking around any more than that.