Mash Tun Sizing - What can I get by with?

[Nagorg]

Hello,

First I want to be sure everyone knows I have read the sticky below:

https://www.homebrewtalk.com/f11/how-big-your-mash-tun-needs-123585/

Yes, I can decipher the chart. However, I have recently stepped up my brew kettle for 10-15 gallon batches.

My current mash tun is a 48QT Igloo Marine cooler. I understand that this size would be roughly considered a 10 Gallon MT and using the chart in the sticky, I'm looking at a max of 1.060 OG for a 10 gallon batch @70% efficiency.

So, I routinely brew beers around or above that OG and have been thinking of building a 70QT MT and I know it will be big enough for me. (Coleman Xtreme)

However I am wondering two things:

1) Would the 70QT Cooler MT be problematic for smaller, 5 gallon, batches?
2) What are the chances that my existing 40-48QT Cooler MT might be fine for 10G batches with OG's of say 1.065-1.075 if I mashed thick and split my sparge into multiple batches?

Does anyone have any first hand experience here that might help me either pull the trigger on the lager MT or just stick with what I have for now?

BTW: These are rectangle shaped coolers and I batch sparge.

Thanks for any insight here...

 

[sj3324]

My recommendation would be to just try out your existing mash tun. What is the worst that could happen?

As far as the larger one being problematic I have no idea, but I would think the main problem would be more heat loss due to the larger headspace.

 

[Nagorg]

Great point on the heat loss. I guess I may just have to try brewing a ~1.070 beer to see what troubles I run into. I guess the main problems would probably be too thick of a mash and small trouble getting to proper boil volume as a result.

I suppose I was hoping someone else had already gone down this path and would share their real world experience to help sway me one way or another. So, I may update my post later with the results.

 

[Nagorg]

I seem to have found posts where people say the 70QT cooler MT shouldn't really be too big for 5 G batches.

http://www.homebrewersassociation.org/forum/index.php?topic=9835.0

I guess I'm off to build a bigger MT. Sure wish I had room to store both when I'm done.

 

[Nagorg]

70 QT cooler acquired. Ball valve next. BargainFittings here I come!