Mash Techniques

[flavaham]

I've done about 6 all-grain batches now. All have been single infusion. I'm wondering what is involved to do step infusion, why this is done and how to do it with a more-or-less starter mash set-up. (10 gallon water cooler converted into mash tun) I put my recipes together on my own so I always do a single infusion. A red ale that I'm making this weekend will call for torrified wheat. I'm not sure if a single infusion will do for this .
thanks,
-g

[brewmeisterintng]

Used when brewing with low- to moderately-modified malts
What makes a multiple-step infusion mash different from a singe-step infusion mash is the inclusion of a protein rest of 20-30 minutes at or near 122

[BillyBock]

Before doing a step-mash, you should have in mind what results you're after. Bear in mind that mashing is really just a continuation of the malting process. Different temperature rests in the mash cycle favor different enzymes in the grain--each has a purpose. With low or poorly modified malt a lot of these rests are necessary. Conversely, with today's modern malts an infusion rest is sufficient. There are numerous rests; to name them:

Acid Rest (95F-104F): Optimal for beta-glucanase which leads to a better modification of gums which improves lautering as well as beer filterability. This rest, through liquefaction, also helps prep the enzyme system for higher temperature rests.

Protein Rest (113F-131F): A rest at 113F-122F favors breakdown of medium molecular weight proteins into smaller units, while a rest at 122F-131F favors action on the high molecular weight proteins.

Beta-Amylase Rest (140F-148F): Optimal for beta-amylase activity. A rest in this range favors increase the real degree of fermentability (RDF)--ie. makes the wort for fermentable.

Alpha-Amylase Rest (154F-162F): Optimal for alpha-amylase activity. A rest in this range favors a decrease in the RDF by producing body-building dextrins in the wort.

Mash Out Rest (165F-170F): A 15-20 minutes rest halts enzymatic activity--stops breakdown and conversion.

Note: if you use a protein rest with highly modified malt, keep it to less than 20 minutes or you risk breaking down the proteins too much and not having enough to support building a nice, frothy, foamy head--you want the medium weight proteins for this.

Note: mash outs aren't completely, many beginning brewers do a single temperature rest and no more and still make great beer. But this step will help you establish repeatability once you have a mash program down for a recipe.

For your first try and multi-rest infusions, you might want to get the hang of the process by just trying to do a mash-out. Perform your normal rest and then infuse boiling water to bring it to 165F-170F.

To give you an example of a mash schedule, my Kolsch spends 45 minutes at 140F, 15 minutes at 158F, and then 15 minutes at 170F. This promotes a high RDF with a little body.

The torrefied wheat in your recipe is more than likly added to aid in head retention and is probably less than 10% of the grist. Personally I would just single infuse it. There may be a small amount of chill haze from the proteins, but nothing that cold aging wouldn't fix.

With a cooler mashing system, the problem you'll run into is ensuring you have enough room for all the grains and the water needed for temperature boosts. Start with a thick mash (0.75 qts/pound) and then go from there. For more ino check out, 'How to Brew' for more information:
http://www.howtobrew.com/section3/chapter16-2.html

Hope this helps,

v/r
Bill