Underletting With An Irda Pump

[Doc]

I'm looking at underletting the mash for this weekends brew.
I've got about 7kg of grain to underlet with approx 25 litres of water.
I plan to use the IRDA pump.

For those of you who underlet and have knowledge of the IRDA pump, will the pump be up for this volume ?
Any other gotcha's ?

TIA,
Doc

 

[Tony M]

Doc,
I underlet on my gravity setup and the head starts at about 50 cm and ends at about 20 cm. I've never timed it but it is a very few minutes. so you are not looking at any great pressure requirements here.

 

[AndrewQLD]

Wish I could help you Doc, I have the Idra, but have deliberately stayed clear of underletting because I didn't think the pump had enough flow/pressure. However I know nothing about pumps :huh: so please keep us informed.

Andrew

 

[dicko]

Hi Doc,

I too, underlet by gravity only without a problem up to 11 kgs of grain.
I have underlet with my March without a worry so I would suggest that you wouldn't have any worries as long as the inlet of the Idra remains flooded.

Cheers

 

[nonicman]

I have around the same length as Tony for the underlet tube. Using gravity to feed into a round esky. Have done two brews recently with similar volumes (42.5 and 45 litre brews) and have not needed to adjust the underlet tube.

When I fill a keg using gravity I usually shorten the transfer hose mid way, but haven't had to do this with underletting.

 

[GMK]

I agree with DIcko ref the IDRA pump inlet remaining flooded.

But i Underlet using gravity.

I have underlet 13kg of grain with gravity and have had no problems.

Then just lift the mash tun up onto the bench....

 

[Doc]

Excellent.
Sounds like I might be able to do it with gravity. The last few litres may need to go in the top due to gravity not being able to push out the last couple of litres.
Will let you all know how it goes.

Beers,
Doc

 

[dicko]

Excellent.
Sounds like I might be able to do it with gravity. The last few litres may need to go in the top due to gravity not being able to push out the last couple of litres.
Will let you all know how it goes.

Beers,
Doc

[post="58833"][/post]​

Yes Doc,

I have done it that way as well just to speed up the last litre or so going into the mash.
My HLT is immediately above my mash tun and when I am to the bottom of the HLT it is quicker to drop the last litre or so into the top of the tun.

Cheers and happy brewing

 

[beertime]

Hi guys,

I was wondering if you could explain underletting and its purpose

 

[JSB]

IDRA's ROCK!!!!

JSB

 

[Doc]

Hi guys,

I was wondering if you could explain underletting and its purpose

[post="58863"][/post]​

It is the method by which the grist is added to the mash tun and the hot liquor is introduced via the manifold/false bottom outlet.
It can allow for quicker dough in and less dough balls.
I'll be trying this method because I don't have as easy access to my MLT with my new brew rack, and I'm sure my neighbours don't enjoy the sound of a drill at 6am on a Saturday morning when I'm doughing in (I use a paint stirrer on a drill to mix the liquor and grist).

Beers,
Doc

 

[big d]

bit off topic doc but dicko put me onto underletting.its a great way to go and i enjoy watching the strike water as it rises through the grain and changing colours.
just a gentle stir and your away.

cheers
big d

 

[Trough Lolly]

I've read on some O/S forums that an advantage of underletting is that it does away with the need to drop grains into hot mash water. For those of us poor soles who use Rubbermaids, we have to overheat the water so we hit the right mash temp at the end of the dough-in and I'm concerned about scalding / extracting tannins from the first few hundred grams or so of grains in the overheated water - or is this another one of those brewing myths???
TL

 

[dicko]

Hi TL,
I am not sure wether it is a myth but I guess if you look at what happens, the grain at the bottom of the mash tun is subject to the same hotter temp from the HLT during underletting as the grain that is tipped into the hotter water from the top during dough in.

What I have found over time is that the temp stabilises a lot quicker during underletting and there is very little problem with the "dough balls".
I have also noted that the temp of the liquor in the HLT need be a couple of degrees cooler for underletting compared to dough in with my system.

I must stress that this is only my opinion and after having tried it both ways ( a bit like - no I wont say it :lol: ) I find that underletting suits my brewery and the way I have it set up.
I have pumped the underletting procedure but I find gravity works just fine and I am happy with this method.

Cheers

 

[Gulf Brewery]

Dicko

I think you are right in that youo need a lower liquor temperature as less heat is lost whiel you dough in. The heat lost from having an open mash tun, plus any splashing / aerating of the liquor drops it temperature quickly.

Cheers
Pedro

 

[AndrewQLD]

My setup has all three of my vessels on the same level, do you think underletting would work using my Idra pump, given I don't have gravity to assist?

Andrew

 

[dicko]

Hi Andrew,
I really cant see why it would not work providing the inlet is flooded and both inlet and outlet pipes are of a reasonable size.
When I first built my system I used small bore ball valves.
I have now upgraded to full bore ball valves and it makes a difference
( improvement ) to the flow from the pump.
Magnetic drive pumps are not pressure pumps as such but they can handle a bit of outflow resistance.
If you transfer by gravity and underlet the mash and it works now, then the pump will be even better.
As I said in an earlier post with gravity feeding the mash, I let the last litre or so of water in on the top to speed up the dough in as this last litre is slow to run in from the bottom.
Give it a go and keep us informed,
Cheers

 

[Boots]

I hope I'm not overstepping the mark here, but I feel compelled due to Batz's current absence from the forum..... it's what he'd want.

Real brewers use a March Pump h34r:

:lol:

jk of course

 

[Pumpy]

For those of us poor soles who use Rubbermaids, we have to overheat the water so we hit the right mash temp at the end of the dough-in and I'm concerned about scalding / extracting tannins from the first few hundred grams or so of grains in the overheated water - or is this another one of those brewing myths???

Trough Lolly

I have a Rubbermaid cooler and have taken to just doughing in a 19 litre Ally pot getting it up too temp on the gas then transferring ithe mash into the prewarmed Tun .
The old Palmer way I always used to end up adding a lot of hot water to get up to temp and I reckon it caused compression of the grain bed and slow sparge , since I done this way it is so much better sounds messy but it is really not .

Pumpy

 

[Doc]

Underlet 25 litres of hot liquor this morning using gravity.
Piece of cake, once I got the kink out of the transfer tube.
Had to add about a litre of cold as the mash was slightly over temp, but no dramas. All is good.

Beers,
Doc