Stuck mash

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Jocky
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Re: Stuck mash

Post by Jocky » Sat Sep 29, 2018 3:46 pm

Annnnd?
Ingredients: Water, Barley, Hops, Yeast, Seaweed, Blood, Sweat, The swim bladder of a sturgeon, My enemies tears, Scenes of mild peril, An otter's handbag and Riboflavin.

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Re: Stuck mash

Post by bitter_dave » Sat Sep 29, 2018 7:06 pm

Jocky wrote:
Sat Sep 29, 2018 3:46 pm
Annnnd?
... and not had a chance to try it out as not been able to find the time to brew. I’ll update this when I do. Currently drinking the beer that stuck and it’s not bad, which just goes to show beer usually comes out ok in the end :)

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Re: Stuck mash

Post by bitter_dave » Sat Oct 06, 2018 9:37 pm

bitter_dave wrote:
Fri Aug 24, 2018 10:37 pm
Just as a quick update, as you will recall I was having problems with stuck mashes. It was suggested that the problem might be solved by using a rigid pipe from the tap to the false bottom. As an easy solution, I decided to cover the plastic tubing I was using with some 15mm copper pipe (see photo below).This seems to keep the plate more rigidly in place and should prevent the tubing being crushed by the weight of the grain. If it works I’ll be dead chuffed :)
Well as my kids would say, that was an epic fail! Brewed today (Mackeson Stout style beer) and stuck mash. Ended up going to shop and buying a Richie’s mash / sparging bag and tipping mash into the bag / a fermenting bin. Annoying. Not massively impressed by the bag either - bizarre shape. I’m going to completely rethink this as the false bottom is not working for me.

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Stuck mash

Post by dbambrick996 » Sat Oct 06, 2018 11:09 pm

If you are milling your own grain check the crush , also get some oat husks it will help

I have a similar setup and was getting stuck mash as my crush size was too fine for my system. I now find that a crush if 1.1mm works good for me

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Re: Stuck mash

Post by bitter_dave » Sun Oct 07, 2018 8:36 am

dbambrick996 wrote:
Sat Oct 06, 2018 11:09 pm
If you are milling your own grain check the crush , also get some oat husks it will help

I have a similar setup and was getting stuck mash as my crush size was too fine for my system. I now find that a crush if 1.1mm works good for me
Thanks for the suggestion. I get my grain pre-crushed so I don’t think that’s a solution.

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Re: Stuck mash

Post by HTH1975 » Sun Oct 07, 2018 9:11 am

This is a strange one - I’ve got the same type of false bottom with no rubber seal and it sits in the bottom of my mash tun much like yours. I’ve only had one stuck mash in the entire time I’ve brewed probably 20-30 beers on this system (the problem brew was 50% rye).

I too use silicone tubing inside the mash tun, but it doesn’t collapse.

I fill the mash tun with all of my brewing liquor, then add the grist. Are you adding your grains first perhaps?

Runoff/sparge normally takes an hour - I run it nice and slow. I barely crack open the ball valve and wait till I get some wort flowing, but the tap is never more than half open even towards the end of runoff (when it slows down).

This sounds like a process issue rather than your gear. Or maybe you’re expecting your sparge to be faster than an hour for around 25-30L.

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Re: Stuck mash

Post by bitter_dave » Sun Oct 07, 2018 10:00 am

HTH1975 wrote:
Sun Oct 07, 2018 9:11 am
This is a strange one - I’ve got the same type of false bottom with no rubber seal and it sits in the bottom of my mash tun much like yours. I’ve only had one stuck mash in the entire time I’ve brewed probably 20-30 beers on this system (the problem brew was 50% rye).

I too use silicone tubing inside the mash tun, but it doesn’t collapse.

I fill the mash tun with all of my brewing liquor, then add the grist. Are you adding your grains first perhaps?

Runoff/sparge normally takes an hour - I run it nice and slow. I barely crack open the ball valve and wait till I get some wort flowing, but the tap is never more than half open even towards the end of runoff (when it slows down).

This sounds like a process issue rather than your gear. Or maybe you’re expecting your sparge to be faster than an hour for around 25-30L.
I add the grain to the water slowly while stirring and stir until I get consistent temps in different parts of the mash tun.

I batch sparge, which might contribute to to problem perhaps but I let the grain settle for a bit.

The wort only comes out in a slow trickle, so it’s not me being too impatient.

It may well be that my technique is the issue. It was easier in the old days when all I had was a bin with holes in acting as a filter - I may return to this!

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Re: Stuck mash

Post by dbambrick996 » Sun Oct 07, 2018 10:23 am

bitter_dave wrote:
dbambrick996 wrote:
Sat Oct 06, 2018 11:09 pm
If you are milling your own grain check the crush , also get some oat husks it will help

I have a similar setup and was getting stuck mash as my crush size was too fine for my system. I now find that a crush if 1.1mm works good for me
Thanks for the suggestion. I get my grain pre-crushed so I don’t think that’s a solution.
It might be the only way to solve your issue with your current setup

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Re: Stuck mash

Post by HTH1975 » Sun Oct 07, 2018 6:42 pm

bitter_dave wrote:
Sun Oct 07, 2018 10:00 am
HTH1975 wrote:
Sun Oct 07, 2018 9:11 am
This is a strange one - I’ve got the same type of false bottom with no rubber seal and it sits in the bottom of my mash tun much like yours. I’ve only had one stuck mash in the entire time I’ve brewed probably 20-30 beers on this system (the problem brew was 50% rye).

I too use silicone tubing inside the mash tun, but it doesn’t collapse.

I fill the mash tun with all of my brewing liquor, then add the grist. Are you adding your grains first perhaps?

Runoff/sparge normally takes an hour - I run it nice and slow. I barely crack open the ball valve and wait till I get some wort flowing, but the tap is never more than half open even towards the end of runoff (when it slows down).

This sounds like a process issue rather than your gear. Or maybe you’re expecting your sparge to be faster than an hour for around 25-30L.
I add the grain to the water slowly while stirring and stir until I get consistent temps in different parts of the mash tun.

I batch sparge, which might contribute to to problem perhaps but I let the grain settle for a bit.

The wort only comes out in a slow trickle, so it’s not me being too impatient.

It may well be that my technique is the issue. It was easier in the old days when all I had was a bin with holes in acting as a filter - I may return to this!
I used to batch sparge too, but never got stuck mashes so I doubt that’s your problem.

What is your mash thickness? Are you in the 2.5-3L/Kg range?

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Re: Stuck mash

Post by bitter_dave » Sun Oct 07, 2018 7:43 pm

HTH1975 wrote:
Sun Oct 07, 2018 6:42 pm
bitter_dave wrote:
Sun Oct 07, 2018 10:00 am
HTH1975 wrote:
Sun Oct 07, 2018 9:11 am
This is a strange one - I’ve got the same type of false bottom with no rubber seal and it sits in the bottom of my mash tun much like yours. I’ve only had one stuck mash in the entire time I’ve brewed probably 20-30 beers on this system (the problem brew was 50% rye).

I too use silicone tubing inside the mash tun, but it doesn’t collapse.

I fill the mash tun with all of my brewing liquor, then add the grist. Are you adding your grains first perhaps?

Runoff/sparge normally takes an hour - I run it nice and slow. I barely crack open the ball valve and wait till I get some wort flowing, but the tap is never more than half open even towards the end of runoff (when it slows down).

This sounds like a process issue rather than your gear. Or maybe you’re expecting your sparge to be faster than an hour for around 25-30L.
I add the grain to the water slowly while stirring and stir until I get consistent temps in different parts of the mash tun.

I batch sparge, which might contribute to to problem perhaps but I let the grain settle for a bit.

The wort only comes out in a slow trickle, so it’s not me being too impatient.

It may well be that my technique is the issue. It was easier in the old days when all I had was a bin with holes in acting as a filter - I may return to this!
I used to batch sparge too, but never got stuck mashes so I doubt that’s your problem.

What is your mash thickness? Are you in the 2.5-3L/Kg range?
I use about 2.5, or slightly over. On this occasion I used 10 litres for about 3.8 kilo of grain. I top up the mash after the mash is over as per the batch sparge calculator instructions on this site, so there is considerably more liquid when I drain the tun. I don’t think the Black malt helped on this occasion much this time around, but don’t usually use it.

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Re: Stuck mash

Post by guypettigrew » Sun Oct 07, 2018 8:40 pm

Howdy BD

None of this is making any sense, as you're probably realising.

Everything you're doing seems right. The grain crush is probably good, the grain to liquor ratio is fine, you're opening the tap slowly, the mash temperature is good, the run off tube is protected from collapsing, but the run off is still stuck. Even on the first run off before batch sparging.

As Sherlock Holmes said (sort of) 'when you've eliminated the possibles, look at the impossibles'.

Your first run off is blocked, which suggests something is wrong very early in the process. It's unlikely the grain is setting hard and stopping the flow. The false bottom must be blocked at the beginning of, or during, the mash.

Here's my latest thought on the problem. Is there any chance that, as you're stirring the mash, you're shoving the grain into the holes in the false bottom? Sounds bonkers, but there has to be some reason why the wort can't get out of the mash tun.

As I stir the mash I always lift it up from the bottom of the tun. Not to avoid blocking the holes, but to circulate the colder stuff upwards to get a proper temperature distribution.

You may not even be aware of doing this, but something's blocking the holes in the false bottom.

If this isn't the answer, then we'll all keep thinking!

Guy

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Re: Stuck mash

Post by bitter_dave » Sun Oct 07, 2018 9:29 pm

guypettigrew wrote:
Sun Oct 07, 2018 8:40 pm
Howdy BD

Here's my latest thought on the problem. Is there any chance that, as you're stirring the mash, you're shoving the grain into the holes in the false bottom? Sounds bonkers, but there has to be some reason why the wort can't get out of the mash tun.

As I stir the mash I always lift it up from the bottom of the tun. Not to avoid blocking the holes, but to circulate the colder stuff upwards to get a proper temperature distribution.

You may not even be aware of doing this, but something's blocking the holes in the false bottom.

If this isn't the answer, then we'll all keep thinking!

Guy
Hi Guy, thanks for the suggestion; it’s an interesting theory. I’m not aware of doing that but I might be doing it inadvertently.

I think I’m just going to ditch the false bottom and try something else. For whatever reason it's not working for me. One option I thought of was to find a fermenting bin that will fit inside the mash tun and drill small holes in the bottom to make a kind of basket that rests on the tap bolt. An alternative is to make some kind of braid, but I’m attracted to the basket option

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Re: Stuck mash

Post by RobP » Sun Oct 07, 2018 10:32 pm

jsebright wrote:
Sat Aug 11, 2018 3:23 pm
I had a similar problem a while ago with a very similar false bottom. A very frustrating brew day which saw me scooping out the mash into a muslin bag and making a temporary straining bucket. Fortunately the resulting brew was very good.

I eventually realised the problem was to do with not enough space underneath the dome so the bottom of the threaded stainless connector was sealing against the bottom of the mash tun.

I had a threaded elbow going through the dome with a nut underneath. I fixed it by putting a stainless washer above the dome, just under the elbow, lifting the bottom of the "pipe" up by 1 or 2 mm. This did the trick and it hasn't been a problem since.

Edited to explain it better after looking at my setup.
Have you considered this? Weight of grain closing outlet?

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Re: Stuck mash

Post by guypettigrew » Mon Oct 08, 2018 8:26 am

bitter_dave wrote:
Sun Oct 07, 2018 9:29 pm

Hi Guy, thanks for the suggestion; it’s an interesting theory. I’m not aware of doing that but I might be doing it inadvertently.

I think I’m just going to ditch the false bottom and try something else. For whatever reason it's not working for me. One option I thought of was to find a fermenting bin that will fit inside the mash tun and drill small holes in the bottom to make a kind of basket that rests on the tap bolt. An alternative is to make some kind of braid, but I’m attracted to the basket option
Ah, the old 'Dave Line' approach! My very first mashes many decades ago were done in a double bucket system. Never really got on well with it. The inner bucket always got jammed inside the outer one. Then I moved onto a canvas bag with a mesh bottom. Can't for the life of me remember how I supported the mesh. But I do remember wrapping the bucket round with two layers of hot water tank insulation material. Then I moved on to the faithful cooler box with a slotted 'D' manifold.

The only stuck mashes I ever had were with the double bucket. I think I drilled the holes too large and some grain got through and blocked the tap. Can't really remember, though. It was way back in the late '70s!

None of this is any help to you, I know! Just a chance for me to reminisce.

Looking at your recent posts I see you top up the mash with water before running the wort off. Have you tried running the wort off at the end of the mash time before topping up with water? I'm just wondering if adding more water is stirring things up and causing it to clog before a proper filter bed of grain has formed on top of your false bottom.

I've never batch sparged, by the way, so probably don't know what I'm talking about!

Guy

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Re: Stuck mash

Post by bitter_dave » Mon Oct 08, 2018 8:37 am

RobP wrote:
Sun Oct 07, 2018 10:32 pm
jsebright wrote:
Sat Aug 11, 2018 3:23 pm

I had a threaded elbow going through the dome with a nut underneath. I fixed it by putting a stainless washer above the dome, just under the elbow, lifting the bottom of the "pipe" up by 1 or 2 mm. This did the trick and it hasn't been a problem since.

Edited to explain it better after looking at my setup.
Have you considered this? Weight of grain closing outlet?
I did look into this and I checked the clearence at the bottom and it looked ok, but perhaps the weight of grain does push the false bottom down a bit, but there is no pipe coming out of the bottom of the nut to lift up; thanks for highlighting this tho

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