quick decoction question

[bmason1623]

My next brew will be my first time doing a decoction, a double decoction to be exact. I understand all of the steps required that beersmith provides except for the last step- "Mash Out". Below are the steps per beersmith:

Name Description Step Temp Step Time
Protein Rest Add 4.50 gal of water at 129.4 F 122.0 F 35 min
Saccharification Decoct 1.51 gal of mash and boil it 147.0 F 20 min
Saccharification Decoct 0.92 gal of mash and boil it 158.0 F 20 min
Mash Out Heat to 168.0 F over 10 min 168.0 F 10 min

On the "Mash Out" step, do i drain my lauter tun to a pot and raise its temperature to 168F then return it to the lauter tun and then re-drain to my boiling pot and begin batch sparging? I think I'm over analyzing this and the obvious is not so obvious to me. Thanks.

 

[Hammy71]

I usually just skip the mash out and just sparge with hot water. You want to bring the grain temp over 168 to stop conversion. You can do this by heating your mash tun, adding boiling water to the mash, or simply skip and sparge with hot water.

 

[motobrewer]

beersmith is assuming you have a direct fired mash tun, so it's telling you to turn the burner on and heat it to 168.

if you don't have a metal tun, you could:
1. do an infusion to get to mash out.
2. do another decoction to get to mash out.
3. skip the mashout.

i'd skip it personally. where did you get that mash program? beersmith's default decoction programs are more or less placeholders in my opinion. what are you brewing?

i'd check out these double decoction programs:
https://www.homebrewtalk.com/wiki/index.php/Decoction_mash#Double_Decoction

 

[bmason1623]

I plan on brewing Brad's Vienna Lager <https://www.homebrewtalk.com/f59/brads-vienna-lager-80356/>.

I'm using a 10 gallon round cooler and not a steel mash tun. So if I skip the mash out, just drain the runnings (which according to beersmith's calculations on line #3 of my mash steps) will be at 158F approximately. Once it's drained, I just batch sparge as usual?

 

[motobrewer]

yes, just drain the 1st runnings completely and batch sparge as normal.

I like to use hot sparge water to try to get the grainbed up to mashout temps (160-170). usually takes close to boiling water to get there.

 

[Yukmay]

If you do decide to do a mashout decoction:

A simple formula to use is: Mash Volume X ((Temp Desired - Current Temp) / (Temp Decoction - Current Temp))

So for a 3.3 Gal mash to take from 151F to 170F (mashout temp) it would be 3.3 X ((170-151)/(212-151)).

At least that's the formula I've been using. It usually ends up being about 33% of the mash volume which has to be 'decocted' for mashout.