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Brewing Topics => Brewing Discussion => Topic started by: MarkWebb on November 07, 2019, 11:41:00 PM

Title: Multiple Step Mashing with small Mash Tun
Post by: MarkWebb on November 07, 2019, 11:41:00 PM
I have a recipe that has the following mash steps -
"Mash in at 62 deg C for 20 mins then raise to 68 deg C for 30 mins.
Mash out at 75 deg C for 10 mins."

Want to use 32 liters of water.

My tun is a 15 liter cooler box so I can't increase temperature in the tun.
----------------------------------------------------------------------------------
Can I do the following?
Step 1 - add 12 L at 62 deg C for 20 mins. Empty into boil kettle.
Step 2 - add 10 L at 68 deg C for 30 mins. Empty into boil kettle.
Step 3 - add 10 L at 75 deg C for 10 mins. Empty into boil kettle.

My concern is that none of the water has been on the grain for the full hour - is this problematic?
A small tun is nice if one want to pick it up onto a table to drain into the boil pot.

Regards
Mark
Title: Re: Multiple Step Mashing with small Mash Tun
Post by: BOB357 on November 08, 2019, 03:25:45 AM
The results of doing your water switching routine would be very interesting, but I'm pretty sure the beer would suffer.

Your best bet is to just do a single infusion mash at 65C. The first 2 steps of your recipe might lead to a slightly more fermentable wort than the single infusion, but extending the mash time to 90 minutes would likely give similar results. Unless you fly sparge, the mashout step is pretty much a waste of time.
Title: Re: Multiple Step Mashing with small Mash Tun
Post by: Oginme on November 08, 2019, 05:24:23 AM
In your initial infusion at 62C, you will solubilize the enzymes you need to reduce the starches to sugars.  At that temperature, however, not all the starches will be available, as the gelatinization temperatures for some of the longer and higher branched starches will not become soluble until you reach around 64C.  When you drain the wort from this first infusion, you will carry away most of the enzymes you need for further conversion of the starches still in the barley kernels.  Doing this will not perform what the initial intent of the mash profile you wish to occur -- the further reduction of longer starch chains into more fermentable species.

I see a couple of options for you.  The first is to do as Bob357 recommends and move to a single infusion at around 64C or 65C.  64C should give you a slightly more fermentable wort.

The other is to use a decoction to raise the temperature.  In the decoction, you will remove the thick part of the mash (grains and a little wort) and leave behind much of the liquid with the enzymes continuing to work on the soluble starches in the wort.  Since you are really only looking to raise the temperature, you do not have to boil the thick decoction for very long, maybe a few minutes before returning it to the mash tun to raise the temperature.  BeerSmith does give the amounts of grain/wort which needs to be removed and decocted to bring the temperature up to the next step.  Through my own experience with this, I usually pull about 15% more for the decoction than it calls for in order to hit the target temperatures.  My guess is that because I have done this with a BIAB mash and have the 'adjust equip for temp' turned off, that this is the main reason for needing more mass for the temperature rise.

Another concern that I have is the water to grain ratio in your mash tun from the start.  I don't know how much grain is in your recipe, but if your initial infusion is below 2.6 l/kg then you will not have enough water to perform efficient starch solubilization.  If this is the case, I would suggest another alternative which would be to split your grain bill in half and conduct two mashes back to back. 

Title: Re: Multiple Step Mashing with small Mash Tun
Post by: Kevin58 on November 08, 2019, 08:15:55 AM
In most cases when you look at a recipe keep in mind, that'show the other brewer decided to make that beer. If a step mash doesn't work for you because of equipment limitations then by all means do a single infusion. In the grand scheme of things its not going to make that much difference.
Title: Re: Multiple Step Mashing with small Mash Tun
Post by: MarkWebb on November 08, 2019, 09:32:36 PM
Thanks guys. Useful information - may consider a bigger tun or stick with my usual single infusion. Regards
Title: Re: Multiple Step Mashing with small Mash Tun
Post by: Brew Bama on November 12, 2019, 06:40:08 AM
You could do a decoction mash to raise the temp vs water infusions.
Title: Re: Multiple Step Mashing with small Mash Tun
Post by: Eric19312 on November 15, 2019, 03:09:01 PM
+1 to brewbama's suggestion on a decoction

when I mashed in a cooler I almost always did step mashing that way and it worked great.