Shallow grain beds

[jwbeard]

I currently use a 10 gallon (round) cooler for mashing, but am toying with the idea of upgrading to a 15 gallon kettle mash tun. The last brew I did in the cooler (a ten gallon beer at 1.056) required breaking the grain into two mashes. Not ideal. Plus, being able to do direct heating is a huge plus, and I like that i'd be able to do step mashes and recirculate heat using a pump during mash out.

My main concern is what happens when I want to do smaller batches. We don't drink beer quickly, though for some batches (lagers especially) I see myself doing 10 gallon batches even when there's not a party to plan for. But for day-to-day brewing, to have any variety on tap I'd probably be doing 5 gallon batches.

So: I'm concerned with the effect of a shallow grain bed when I do a 5gallon ale (especially a low gravity session or hefe) in a 15 gallon kettle. I understand one of the main issues being the bed's reduced efficacy as a filter - is this something that a longer vorlauf using the pump could solve? Any other issues with having a shallower grain bed? Not sure I would want to keep the old mash tun around, much less convince SWMBO that it was worth having two tuns...

Thanks for any thoughts!

 

[Near-Beer-Engineer]

I have never done a super shallow grain bed before, although I have thought about doing this before. There may actually be some benefits to it, such as better efficiency due to lower chances of malt clumping (since you can mix it pretty thoroughly), as well as lower chances of channeling (less chance of "stuck" areas that force the flow around them, limited efficiency).

You're probably right that the thinner bed will be a poorer filter, although I think as long as there's a few centimeters of grain a few vorlaufs will work just fine. You can always add some rice hulls to build up the grain bed a bit too. They won't affect the gravity/flavour, just give them a rinse (to remove any "dust" and to pre-absorb any water) and mix them in.

Just my 2 cents, someone with more experience may prove me wrong.

 

[BadWolfBrewing]

I do many 5g batches in a 20 gallon mlt from stout tanks. Works fine, no issues. I normally batch sparge or no sparge with really small grain bills.

 

[BadWolfBrewing]

Oh, and I continuously recirc through the mash

 

[jwbeard]

Awesome - thanks!