Underletting

[jmc]

obviously youd need to pump hlt water into mashtun or the head pressure from the mashtun filling up wouldn't allow much hlt water if doing it from gravity???
nice idea will give it a go, pita them doughballs bastards

No need for pumping. Gravity will do the job on homebrew scale. See pic in my previous post.

[jakey.goodman]

I really fancy giving this a go- how much temp do you usually loose using underletting compared too the usual doughing in (or is it too hard to say due to varying equipment)? I usually work out a rough loss of 10 degrees from HLT to mashtun using the '1 kettle of boiling water to pre-heat the mashtun, empty, pour liquor in, then add grain approach'. Would this be considerably different in terms of temperature loss?

[jmc]

I really fancy giving this a go- how much temp do you usually loose using underletting compared too the usual doughing in (or is it too hard to say due to varying equipment)? I usually work out a rough loss of 10 degrees from HLT to mashtun using the '1 kettle of boiling water to pre-heat the mashtun, empty, pour liquor in, then add grain approach'. Would this be considerably different in terms of temperature loss?

Strike temp will depend on grain temp and mash ratio.
As long as mash-tun is pre-heated you can use the normal strike temperature calculations like Andy's one here.

[darkonnis]

See I just chuck the water in first, then add the grain... Then mix, that way all the grain has to go through the water to settle on the bottom. You don't get dough balls, and you only need the one hand *shrug* I might try underletting but being honest, seems very much like 6 and 2*3s.

[FUBAR]

Think I will try underletting on my next brewday now that I've upgraded to bigger gear (Barneey's Thermopots)as trying to tip 12+kilos of grain and stir at the same time is indeed a PITA,plus it should hopefully cut down on the amount of Barley dust that I get when slowly tipping grain in to the Tun.

[chastuck]

Think I will try underletting on my next brewday now that I've upgraded to bigger gear (Barneey's Thermopots)as trying to tip 12+kilos of grain and stir at the same time is indeed a PITA,plus it should hopefully cut down on the amount of Barley dust that I get when slowly tipping grain in to the Tun.

Alright, underletting does seem to be another way of mashing grain in a mash tun. But how does the grain get into the tun in the first place? Surely you still have to tip the dry grain into the tun before you start the underlet - it doesn't get there on its own! And if you are using a mix of grains and perhaps mash salts you will have to dry stir first to mix it all. So how does this differ from pouring the dry grain into mash liquor? Seems to me whatever way you do it you've still got to pour grain into the mash tun. Underletting seems to add another stage stage in that you have to pre-heat the mash tun and then pour the hot water away before the dry grain goes in, whereas pre-heating the tun with the mashing liquor and waiting for the correct temperature to stabilise before adding the grain seems simpler.

[FUBAR]

Perhaps I should have said that I brew in the kitchen so using the underletting method I can take the Mash Tun outside and tip the grain in,it can make as much dust as it likes then

[chastuck]

Perhaps I should have said that I brew in the kitchen so using the underletting method I can take the Mash Tun outside and tip the grain in,it can make as much dust as it likes then

Ah!................ I see what you mean. My SWMBO always complains about the dust getting everywhere in the kitchen when I brew. Putting grain in the tun outside makes sense.

[greenxpaddy]

Barney mentioned the possibility of underletting to me the other day. My 200L MT is cylindrical and quite tall and when it is full even with a plaster mixer on a drill it doesn't reach the bottom and agitate that deep. So it seemed like a method worth investigating

I was wondering about the denaturing of enzymes. If the underlet water is at say 75 degrees that's going to denature some of the enzymes in the grain at the bottom of the MT, which will shift to a consistent near-75 degrees once the underletting is well underway. ( I mean the bottom grains will be hotter than the grains at the top of the MT). I would have thought enzyme denaturing would be more significant underletting than with the normal grain to liquor method, even if the complete dough-in with the latter is slower (because I have to stop half way through dumping the grain in and mixing it up before the mash gets too thick). Beta amylase starts to denature at 68c I believe, so a fuller bodied beer is likely to result from underletting. Graham Wheeler suggests a MT temp of 66c as ideal for UK styles which infers some beta amylase activity is desirable. With UK grain bills the Lintner values are more than generous so there should be enough beta amylase in the grain towards the top of the MT to convert the full mash properly. However I would still imagine that these would need distributing throughout the mash so stirring is going to be required anyway.

After consideration I think better results would be seen with grain into liquor. Whether the difference is discernible in the beer I don't know. Maybe others can say if they have tried both methods on the same beer and compared.

[Martin G]

Earlier in the thread someone mentions dry heating the grain in an airing cupboard. Dry heating the grain seems a good way to reduce the strike temp?

[jmc]

Barney mentioned the possibility of underletting to me the other day. My 200L MT is cylindrical and quite tall and when it is full even with a plaster mixer on a drill it doesn't reach the bottom and agitate that deep. So it seemed like a method worth investigating

I was wondering about the denaturing of enzymes. If the underlet water is at say 75 degrees that's going to denature some of the enzymes in the grain at the bottom of the MT, which will shift to a consistent near-75 degrees once the underletting is well underway. ( I mean the bottom grains will be hotter than the grains at the top of the MT). I would have thought enzyme denaturing would be more significant underletting than with the normal grain to liquor method, even if the complete dough-in with the latter is slower (because I have to stop half way through dumping the grain in and mixing it up before the mash gets too thick). Beta amylase starts to denature at 68c I believe, so a fuller bodied beer is likely to result from underletting. Graham Wheeler suggests a MT temp of 66c as ideal for UK styles which infers some beta amylase activity is desirable. With UK grain bills the Lintner values are more than generous so there should be enough beta amylase in the grain towards the top of the MT to convert the full mash properly. However I would still imagine that these would need distributing throughout the mash so stirring is going to be required anyway.

After consideration I think better results would be seen with grain into liquor. Whether the difference is discernible in the beer I don't know. Maybe others can say if they have tried both methods on the same beer and compared.

In both options you're mixing grain with water hotter than the denaturing temp so its 6 & 2 3s. I can't see that underletting will cause more denaturing. If anything the larger mass of grain present when the water comes in will quickly cool it down, so it may be less stressful to the enzymes. (just guessing)

People have been using both methods for years so I just think its a matter of personal preference and what you're used to.

[greenxpaddy]

With under letting a small proportion of grains get the brunt of the heat in the liquor. Tipping in, all the grains get a short burst of heat and no prolonged exposure to high heat. An interesting comparison and one that needs an answer!

[Horatio]

Unless you can tip all your grain into the mash liquor at exactly the same time there will always be the first grains hitting the hot liquor that take the brunt of the heat. It's either water hitting the bottom of the grain or the grain hitting the top of the water. Underletting hasn't had any detrimental effect on my brewing? I find it gives me a greater efficiency too; no dough balls whatsoever and minimal stirring required. Each to their own though and if it ain't broke, don't fix t I suppose?

[Aleman]

If you retorrify your grist then the difference between grain temp and strike temp is quite low and the danger of excessive denaturing of the enzymes at the start of the mash is significantly reduced

[jmc]

If you retorrify your grist then the difference between grain temp and strike temp is quite low and the danger of excessive denaturing of the enzymes at the start of the mash is significantly reduced

Cheers Aleman.
I'd not heard of Retorrification before.

Sounds locical but maybe difficult and (energy expensive) for home brewers to do.
ATB John