Reiterated Mashing

So in December of this past year when my BYO came, I saw an article by Chris Colby about this new technique for brewing high gravity beers. While I was not able to find an online version of the article, you can order it from BYO here or you can hear a really informative interview with James from Basic Brewing Radio here (November 22, 2007) on it.

Reading the article really gave me a lot to think about. Three things come to mind:

1) Is this worth all the work?
2) what's the benefit?
3) If this is some magic way to maximize your grain bill, why not do it all the time?

Well after listening to James' interview and reading a bunch of forum threads on it (here, here and here), I came up with some answers to these questions:

1) Making a big beer is always one of several things, work, time or money.
2) The benefit is being able to make a big beer with a normal mash tun and with out having to boil down 20 gallons of wort
3) No magic, just a way to deal with a 40lb grain bill on a 12 gallon mash tun and a 15gal brew kettle

So after some reading and a meeting with Nick, we decided to take the plunge and we are going to brew a Kaffir Lime Imperial Lager. Here is the recipe:


Recipe Specifications
--------------------------
Batch Size: 10.50 gal
Boil Size: 11.70 gal
Estimated OG: 1.080 SG
Estimated Color: 3.9 SRM
Estimated IBU: 15.7 IBU
Brewhouse Efficiency: 60.0 %
Boil Time: 45 Minutes

Ingredients:
------------
Amount Item Type % or IBU
30.00 lb Pilsner (2 Row) UK (1.0 SRM) Grain 75.0 %
8.00 lb Rice, Flaked (1.0 SRM) Grain 20.0 %
2.00 lb Pale Malt (6 Row) US (2.0 SRM) Grain 5.0 %
3.00 oz Saaz [4.00%] (45 min) Hops 15.7 IBU
Munich Lager #2308 (reused from Samuel Jackson)

Now there are a few things going on here that I need to explain. First off the rice. While flaked rice (rice that is pregelatinized) is the recommended method of using rice as an adjunct, we are going to be using plain white rice because of the lack of availability of flaked rice. So there will be a 1/2 hr rice prep that will either take place the night before or the day of brewing.

With that said, we are going to make our variation on a "reiterated mash":

Reiterated Mashing (our take)

1. 20lbs added to mash tun
2. Strike 10 gal of water at 162 for a grain bed temp of 150
3. Let sit for 20 min
4. Heat up additional 5 gallons water to sparge first 20lbs of grain
5. Runoff into brew kettle - Heat wort up (if necessary)
6. Strike wort from kettle to second 20lbs of grain (in second cooler)with 140-145f grain bed target temp - Rest for 1hr stiring every 10min
7. (in the meantime) Batch sparge 5 gallons of sparge water that was heated up, runoff into second brew pot - Heat up to 140f and hold
8. Empty first 20lbs of grain from mash tun
9. After the hour is up, dump the second 20lbs of grain from second cooler into mash tun along with 2.5 gal of water at 192f for mash out temp - let stand for 10 min.
10. Runoff into brew kettle
11. Use the 5 gallons that was sparged from the first 20lbs to fly sparge the second 20lbs in the mash tun
12. Brew!

From all the reading and listening I did, this process should be about 3hrs on it's own. There are some basic "all grain brewing" aspects of this that are assumed such as recirculation. With that said, there will be minimal to no recirculation before the last runoff because the wort is going into more grain.

After the wort is in the kettle (we are shooting for 11.7gal preboil volume) we will commence with a normal brew day only with a 45min boil to ensure the lightness of the brew.

The kaffir lime is going to be introduced in the secondary. The preparation is for the leaves only. Nick is in charge of this and he is freezing the leaves (20 for a 10.5 gallon batch) and then chopping them up and boiling them. This will make a kaffir lime leaf concentrate and that is what we will introduce to the secondary. It's a pretty interesting idea.

So that's the plan. We are open to feed back as it sounds like there have not been a lot of people out there that have used this approach. I hope that I was able to articulate the technique in a way that makes sense (to those of us above the Mason Dixon line anyway, MNB I am mostly concerned for you as this is pretty confusing).

Cheers!

PS - I am going to take plenty of pictures and try to make a really comprehensive overview of how we are doing this.