Mashtun Size And Efficiency Woes

[MHB]

Plus 1 for what TB said
One of my customers was having a whole world of troubles. Efficiency and attenuation all over the place turned out the thermometer was 5oC out.
Do you have an old fashioned glass laboratory thermometer to calibrate against?

Bottom outlet rather than side can easily give you 2-3 litres more, on a 30 litre knockout theres 6-10% right there.

Most likely it isnt one thing but a combination of factors, you will just have to work through until you get the results youre looking for, but with good insulation a tun like yours can and will give mash efficiency into the 90s.

i am usin g a tooheys keg as a tun, shorter and fatter than my 2 boilers ( which are carlton kegs )

Have you got this the wrong way around? Tooheys kegs are the taller thinner ones, Carlton the shorter fatter, generally I would choose a taller thinner vessel for the mash tun, gives a deeper grain bed and encourages slower sparging (tho 90 minutes isnt bad).

MHB

 

[Screwtop]

Paul,

1. When you brew at your mate's place, do you use his scales or do you weigh out your grain using your scales.

2. Any difference in stirring the mash when at your mate's place

3. What does the mash look like when finished draining at your place. Is there a layer of floury mud over the grainbed?

Screwy

 

[yardy]

3. What does the mash look like when finished draining at your place. Is there a layer of floury mud over the grainbed?

Screwy

without getting into an OT discussion, is this a bad thing ?

cheers
Dave

 

[warra48]

What does the mash look like when finished draining at your place. Is there a layer of floury mud over the grainbed?

I hope it's not a bad thing, because my grainbed looks like that at the end of every batch I brew.

 

[Screwtop]

without getting into an OT discussion, is this a bad thing ?

cheers
Dave

I hope it's not a bad thing, because my grainbed looks like that at the end of every batch I brew.

I really feel like saying "do a freaking search", ........and...................I have this strange twitch.............................. :lol:

Used to suffer from low efficiency and spent a good 6 months modifying processes and equipment in the quest for improved efficiency. One of the many causes of lower efficiency that I found was:

USING MY EQUIPMENT

Stirring the mash more than just a few turns resulted in flour and fine particles being brought into suspension in the mash liquor. The heavy grist settles first and naturally the fine stuff settles last. A layer of fine floury mud settles on top of the grist. When lautering/draining this impervious layer results in the liquor draining mostly down around the edges of the grain bed and reduces efficiency.

Screwy

Edit: to add USING MY EQUIPMENT

 

[yardy]

I really feel like saying "do a freaking search",

Used to suffer from low efficiency and spent a good 6 months modifying processes and equipment in the quest for improved efficiency. One of the many causes of lower efficiency that I found was:

USING MY EQUIPMENT

Stirring the mash more than just a few turns resulted in flour and fine particles being brought into suspension in the mash liquor. The heavy grist settles first and naturally the fine stuff settles last. A layer of fine floury mud settles on top of the grist. When lautering/draining this impervious layer results in the liquor draining mostly down around the edges of the grain bed and reduces efficiency.

Screwy

Edit: to add USING MY EQUIPMENT

without doing a search I'd say what you've described is channeling and is more likely to result from the distance your manifold is from the wall of the tun, rather than how fine the crush is.

Dave


Ritio, back OT

 

[paulwolf350]

Paul,

1. When you brew at your mate's place, do you use his scales or do you weigh out your grain using your scales.

2. Any difference in stirring the mash when at your mate's place

3. What does the mash look like when finished draining at your place. Is there a layer of floury mud over the grainbed?

Screwy

1. if using my grain, I weigh it and crack it and take it over to his house. If using his grain, he weighs and cracks

2. No not really, both stirring about the same, both using gas to heat mash tun directly

3. There definitely used to be, but it have modified my stirring practices, to reduce the mud

Paul

 

[paulwolf350]

Have you got this the wrong way around? Tooheys kegs are the taller thinner ones, Carlton the shorter fatter, generally I would choose a taller thinner vessel for the mash tun, gives a deeper grain bed and encourages slower sparging (tho 90 minutes isnt bad).

MHB

Yes I am a doofus, I am using a "carlton" shaped mash tun, not tooheys

Paul

 

[Screwtop]

without doing a search I'd say what you've described is channeling and is more likely to result from the distance your manifold is from the wall of the tun, rather than how fine the crush is.

Dave


Ritio, back OT

Should have done the search, would have seen it was not related to crush :lol:

Distance from tun wall maybe.....but keeping the stiring to a minimum works.

Screwy

 

[sav]

Paul I use the same tun as you ,12 inch falsie with a 1/2 inch nipple under the bottom to get it lower in the tun my deadspace is about 300ml, And the tap 2inches from the bottom like yours. Before I went to my herms I was getting 75% now I am getting 82%through the herms I found I gained 5 to10 % going a 70min mash over a 60min mash I dont have a answer for you man, And I know how frustrating it must be. All I can say is check ya temp with another therm and keep digging you will have it sussed soon.

 

[MHB]

Direct heating can be an problem, the bottom can get so hot that your killing (all right denaturing) a bunch of enzymes.
The whole wort may not be getting hotter very fast, but the layer near the bottom is different. If you are using direct heat DO STIR and use a very small flame. The difference between you and your mates system could easily be the rate that heat is being applied.
Just one of many possibilities.
MHB

 

[sav]

MHB maybe right I never used direct heat to my mash before I had my herms ,I hit my strike temp dough in and left it for a hour,just put your required water in and heat then dough in and insulate your tun you wont loose that much heat.

 

[KHB]

Before i used my HERMS system i got 68% now i hit 80% everytime. Hope you can work it out mate i would just check all my vloume level and calibrate my thermometers.

CHeers
KHB

 

[Thirsty Boy]

direct heat is bad without agitation of some description, either stirring or re-circulating. The temperature difference between the heated area and the unheated area in an unagitated mash can be massive.

If you do stir - then you need to keep screwtop's experience in mind - it makes (or should make) sod all difference in a batch sparge system where channeling is unimportant - but in a continuous sparge system that layer of mud on top can really stuff things up. Its one of the reasons commercial lauter tuns have rakes. You can poke holes in it or cut it with a knife - but if you ignore it there is a definite potential for it to bugger your continuous sparge efficiency.

Maybe try using something to extend the pick-up point of your tun to the very bottom so you are drawing from the same place as your mate. But remember not to set it up so that when the grain weighs down on the false bottom, it pushes your pick-up tube onto the bottom and seals it off. Cutting a few slots in the end can help give the wort a way to run even if it gets pushed onto the bottom.

I still mainly suspect an inbuilt measuring error. If you were getting 70 and not able to push it up I could understand... but you should be able to do better than 60% with a No-Sparge (or single run-off batch sparge if you prefer) drained through a stainless scrubby... and you have a pretty normal set-up that should work way better than that.

 

[paulwolf350]

I am going to change to a Batch sparge, to eliminate some more variables, and need to check my thermometer

will let you know how i get on

Paul

 

[Screwtop]

The brewers above have raised important points, direct heating does require constant moving of the mash. Tried direct heat myself and had issues with burning using a SSFB and also low attenuation, due to parts of the mash being too hot and low efficiency due to early denaturing of enzymes. Tried a water jacket base and direct heat, but the response was too slow for step mashing. Sorry I missed the bit about direct heat.

Cheers,

Screwy

 

[paulwolf350]

Yeah I know, I need to fast forward my Herms project

Paul

 

[The Mexican]

Yeah I know, I need to fast forward my Herms project

Paul

as an old brewer from the dim dark ages, if your lauter tun temp is consistant & insulated well, I would have a good look at your sprage arm setup, if it is not doing its job correctly, you could be compacting the draff on the top of your grain-bed & causing channeling. With your next brew try cutting or raking the surface of the grain-bed often, do it gently, not too deep, but often. OR... try flood sparging @ 80.C, flood to 50mm above let it sink to 50mm below the grain level, & flood it again etc, keep working the level up & down, & as always, SPARGE SLOWLY.
Another area to consider is your recipe & mash schedule. If you are running a very dextrinous mash without a lower saachrification step, you could be missing out on some of the maltrose.
Just some thoughts, but if all else fails, simply add a bit more grain, or more correctly, set your efficiency in Promash to 60%