Underletting for mash-in

[Rodent]

This week I gave underletting a try when mashing-in, and have to say I should have done this sooner.

I found I was able to hold temps better on a pre-heated mash tun, in large part (I'm assuming) because I kept the lid on until my strike water quantity was fully pumped in. Using my usual strike temp calcs, I actually overshot my mash-in temp by a few degrees and had to add a bit of cold water to bring it down to 149F.

Once filled, I found the grain was evenly soaked and very little stirring was needed to ensure there were no dry spots. I had no issues with dough balls, and the 2-3 small dry spots quickly mixed in with the remainder of wet grain.

A added bonus was that it's a whole lot easier on my shoulder and back to pump water into the grain than it is to add grain, mix, add grain, mix, etc ... to a mash tun full of water.

The only anomaly I encountered was when I swapped hoses around to recirc after filling. Apparently there was a bit of air trapped under the false bottom - not enough to cavitate the pump, but enough to cause my submerged sparge manifold to 'burp' a bit a couple of times during the first few minutes.

I'm sold on this method going forward on future brew days. It was effective and simple to include in my process since I already have a pump and silicone hoses as part of my reddnek HERMS rig.

 

[day_trippr]

When I finished my 3v2p single tier a few years ago ("pre-LoDO") and did a couple of dry runs figuring out the tubing swaps it occurred to me it would be easier to underlet the strike water than run it through the autosparge as there'd be two fewer hose-end swaps to do. It worked great and I've never looked back.

I do give the struck mash a quick stir and that's that. After a 5 minute rest I start recirculating...

Cheers!

 

[mongoose33]

When I finished my 3v2p single tier a few years ago ("pre-LoDO") and did a couple of dry runs figuring out the tubing swaps it occurred to me it would be easier to underlet the strike water than run it through the autosparge as there'd be two fewer hose-end swaps to do. It worked great and I've never looked back.

I do give the struck mash a quick stir and that's that. After a 5 minute rest I start recirculating...

Cheers!

Struck mash, eh? I've never heard that term. I like it.

I was amazed the first time I underlet the grain. No dough balls, not a one.

 

[day_trippr]

Same here. Tbh I don't understand why that's true but I'm fine with it

Cheers!

 

[NTexBrewer]

So I have wanted to try underletting. I have a Fusion 15, 3v2p single tier system.

So would I fill my HLT with my sparge water plus mash water. Heat the HLT to strike temperature and then pump from HLT to Mash Tun.

With underletting do you still try to hit a mash water ratio. Or after underletting a few times can you just underlet until the water is “x” number of inches above the grain bed?

Can I rig my grain mill to sit on my mash tun and crush directly into the mash tun?

Also, with underletting does it work better with large grain bills or is the grain bill not an issue.

I’m usually brewing 5 gallon 5% ABV beers.

 

[day_trippr]

- I underlet the entire prescribed strike water volume per the recipe (which typically runs around 1.25 quarts per pound on my system). It would be the same volume if I poured it atop the grain. As well, the strike water temperature (as prescribed by BS3 for my equipment profile) is the same regardless of how it is introduced to the mash tun.

- Some folks do indeed mill straight into their mash tuns so you'd have company in that regard.

- Grain bill doesn't matter imo. I brew 10 gallon batches and use the same process whether there's 22 pounds or 42 pounds in the tun...

Cheers!

 

[mongoose33]

+1 to what @day_trippr said.

I'm doing a variation on BIAB--I have the entire amount of strike water being underlet in my mash tun. Usually 8 or 8.25 gallons for a 5-gallon batch. I'm accounting for losses in the MT, hoses, BK, etc., which is why it's higher than what i used to do with true BIAB, which would have been 7 or 7.25 gallons.

I'm doing LODO stuff which is why I'm not sparging. But it's essentially the same as if I were doing BIAB.

 

[seatazzz]

I'm having efficiency issues, and I underlet as well. A few batches back I went old school and ran the strike in first, then killed my shoulder by adding the grain. No change in gravity, just lots of swear words. So I went back to underletting. I mash in a bag, with a false bottom as well, so underletting makes the bottom float up a bit and I have to stir it pretty well. But it works.