Underletting

[greenxpaddy]

I'm going to try a halfway house next brew day. Underlet halfway and then top up and add the last 50% of grain. Will report backj

[Horatio]

Don't really see the point in that but do let us know what happens?

[bobsbeer]

I underlet as it seemed easier. I don't bother preheating the MT, but add a couple of degrees to the HLT temp to compensate. Beersmith will do this for you if you know the grain and MT temps. I have a food probe thermometer and stick it in the grain. As my HLT is higher than the MT i just connect up a hose to the MT valve and let it run until the required amount has run in from the scale on the HLT. It's only a 3 ft tube so minimal loss to the pipe.

[DC]

Just been reading this post about underletting after struggling a few times to add grain to my mashtun and being able to stir at the same time without creating clouds of malt dust and dough balls and without help from SWMBO. I am using a 70L Thermopot as a mashtun with a copper manifold (with slots cut in the bottom) as opposed to a false bottom. I was wondering if it would still be possible to underlet into my mashtun via the tap/copper manifold to save me having to pour the grain into the mashtun (water already in mashtun) and stir to remove dough balls.

Would gravity provide enough force to push the mash water into the mashtun via the tap/manifold for doughing in or would I need a pump? Not sure how much heat loss there would be to the mash water by underletting as opposed to adding the grain into a pre heated mashtun, with mash water in?

I would be looking to transfer the water from my HLT to my mashtun via 12mm ID silicone pipe with Cam & Groove fittings on the mashtun end. Not sure how much heat loss there would be to the mash water by underletting (the time it takes to underlet) as opposed to adding the grain into a pre heated mashtun, with mash water in?

Mashtun manifold




If underletting would work with my current mashtun/manifold then that would also do away with having to lift the HLT and pour the mash/sparge water into my mashtun and could even aid in the upgrade from plastic HLT to Shiny HLT.

Any underletting tips greatly received.

Cheers DC

[Aleman]

DC, I under let with and without a pump with no issues . . . I have even under let with the mash tun and HLT on the same level via gravity, with no issues . . . but my HLT is taller (just about) than the mash tun so that there is enough head when it's full to 'drive' the flow into the mash tun. I do use a false bottom in my mash tuns though . . . one bottom draining, and one 'syphon draining.

As for heat loss, I don't really have too much of an issue even brewing outside in the winter . . .if I did then some Armaflex pipe insulation would solve that very quickly.

[greenxpaddy]

Underletting is sometimes useful to blow out a stuck mash bed....

[jmc]

Just been reading this post about underletting after struggling a few times to add grain to my mashtun and being able to stir at the same time without creating clouds of malt dust and dough balls and without help from SWMBO. I am using a 70L Thermopot as a mashtun with a copper manifold (with slots cut in the bottom) as opposed to a false bottom. I was wondering if it would still be possible to underlet into my mashtun via the tap/copper manifold to save me having to pour the grain into the mashtun (water already in mashtun) and stir to remove dough balls.

Would gravity provide enough force to push the mash water into the mashtun via the tap/manifold for doughing in or would I need a pump? Not sure how much heat loss there would be to the mash water by underletting as opposed to adding the grain into a pre heated mashtun, with mash water in?

I would be looking to transfer the water from my HLT to my mashtun via 12mm ID silicone pipe with Cam & Groove fittings on the mashtun end. Not sure how much heat loss there would be to the mash water by underletting (the time it takes to underlet) as opposed to adding the grain into a pre heated mashtun, with mash water in?

Mashtun manifold




If underletting would work with my current mashtun/manifold then that would also do away with having to lift the HLT and pour the mash/sparge water into my mashtun and could even aid in the upgrade from plastic HLT to Shiny HLT.

Any underletting tips greatly received.

Cheers DC

Base of my HLT is only about 70-80 cm above base of my MT
pic below during an underlet.


Water will find a level so no problem just using gravity to underlet.

I generally
- preheat MT with 2 x kettles boiling water & leave for 10 mins
- pour out water from MT
- add grain to MT
- hook up from HLT to MT tap and open up valves

Tube from HLT to MT is now 1/2" silicon so no collapse.
Its made up of 2 lengths with a plastic stop valve in middle, with 'wind-up' hose clips.
Handy as after underletting I can just use top half of tube to batch sparge.
I use bottom half to feed boiler from MT

[barneey]

I was underletting today, might have been doing things a little to quickly at the grain started floating on the water bed, luckily I noticed it in time.

[Aleman]

I was underletting today, might have been doing things a little to quickly at the grain started floating on the water bed, luckily I noticed it in time.

Yep that can be the issue . . . one benefit of doing it by gravity with a very little head . . . it goes slow, and you don't get the grain flating

[barneey]

Yep next time I`m using gravity mine today before I noticed was like a soufflé.

[FUBAR]

I'm finally going to get around to trying underletting tomorrow, so I don't end up with the Grains floating and can get the flow from the HLT correct, what sort of time should I be looking at to underlet 20 litres of Liquor ?

Cheers.

[Matt12398]

We managed to underlet around 15 litres in about 2 or 3 minutes with no grain floating and no dough balls.

[mark4newman]

Hi

I must be odd.

I put some water in, then add some gain, stir, then add some more water, stir, then add some more grain..stir, then put a the rest of the grain in, and then add the rest of the water.....seems to work fine.

Mark

[barneey]

If your trying to empty 20kg of grain in a Tun + stir at the same time - underletting is a lot less hassle.

[FUBAR]

We managed to underlet around 15 litres in about 2 or 3 minutes with no grain floating and no dough balls.

Cheers will keep an eye on the sight tube on the HLT and aim for 5mins to transfer to the Tun.