Mash tun woes

[Stu H]

Okay so a few months ago I "upgraded" from doing dunk-sparge BIAB to using a "proper" mash tun and batch sparging. It has been less than successful to say the least. For one, my efficiency has plummetted, and not only that, it's really unpredictable, and occasionally I have diabolical stuck sparges. I opened up the gap on my mill to compensate, but I'm still ocassionally getting these awful stuck sparges. Last weekend I had to take the mash out of the vessel, and push it through my old voile bag. GARRR!!!

Another problem is my brew software seems to not be able to predict the volumes I'll collect from the sparges, though it was fine with BIAB... Probably doesn't help I'm using crappy old bits of dowel with notches marked in it for my volume measurements.

As far as I can tell, the only real advantage so far about traditional mashing over BIAB is being able to varlauf, meaning clear wort, and less trub in the kettle. However at this stage I'd probably prefer consistency over a trubby kettle.

I'm considering going back to BIAB until I can afford a decent s/s mash tun with a false bottom (probably from Chris Banks).

However I was wondering if you guys had any ideas with what is wrong with my process/equipment before I chuck the baby out of the bathwater, and go back to BIAB, or spend a fortune on stainless? Any help is appreciated!

Here's my mash tun:

[Stu H]

hah, bottom feeder.

ANYWAY good idea, feeding through the braid.

[jt]

I've only ever batch sparged and I've had whopping differences in efficiency over time. Started in the 50's, peaked in the 80's and settled in the 70's
Using a circular tun - it's a 20 litres pail -  with a false bottom and I've always envied the really good & clear runoffs that I've seen people acheive so quickly with braid.

There's so many variables and it took me a while to settle on what worked for me, though I still get patches where everything turns to crap.

The biggies for me were
Getting a reliable crush
Knowing the volumes/deadspace/absorbtion of the mash and tun
Getting the drain volumes even
A good topup/mashout addition into the tun, getting the temperature up, and a stir
Then a rest 10-15 minutes, no stir, plenty of recirculation
A quick tap full open drain
I get a significant drop in mash temp during the recirculation & drain so my batch sparge is hot enough to get the mash temp back up. A stir, a good 10-15 minute rest, recirculate plenty then drain again

I did a few batches all with the same grist weight and liquor volumes to find out what was happening where, good comparisons

Give it time, a few batches, a few tweaks and a enjoy the beers along the way

[Tom C]

I would say your braid is getting crushed, hence the stuck sparges.  I had the same problem which was noticeably worse with larger grain bills to the point where I was shoving a length of wire up the tap to hold it open (and that was with a spring or plastic hose in there to support it too).  The drop in sparge temperature during all this stuffing about would also affect your efficiency.

New manifold would probably make all the difference.

[Liam Callaghan]

Hey Stu,

 

I have had heaps of issues with stuck mash over the years, from pick up pipes to poorly milled grain, even excessive non malt in the mash.  From my experience the grain milling is the most important, cracked not milled to flour.  Glue from flour and water doesn't allow water to pass, pretty easy to fix though by adjusting your mill.  If its your milling it will happen pretty much every time.  Once I changed my source of milled grain my pick up pipe worked a dream.  Unit someone parked a car on it.

 

I have tried the braided hose and found they just blocked up so I don't use them anymore, poorly milled and braid was a definite bad day.  Mate of mine is using braid though and swears by it so it might be the diameter or quality of it.  I have been through 3 copper pipe ones now and think they work the best, slotted on the bottom.  Cheap to make and can be knocked out in a couple of hours

Not much time atm but this is a simple one:-

http://lawrencebrewers.org/lbgforum/viewtopic.php?f=9&t=2126

 

Temperature is also key to getting conversion and extraction.  I tend to run between 75-85% depending on how much time I spend on it, longer is better.  From memory I run about 0.5 litre per minute once its running clear, don't run this fast or you'll have a good chance of compacting the mash and getting stuck.  In my mash tun anyway and its very similar to yours.  I sparge at no more than 77 degrees although have run it higher to check, not much difference.  I also tend to stir the mash every 10 litres of extraction, wait for it to run clear again and keep collecting. This is fly sparging btw to I sprinkle  water on the top of my grain and collect from the tap at about the same rate.  Not sure what the time difference is but it usually takes me about 40-60 minutes to sparge (fly).  Usually with my first pint.  It takes no more than 20-30 seconds to clear between stirring.

 

Another issue I had was stuff getting stuck int he tap, I now run with a 3/4" plastic tap on the MT and I can open it right up if needs be. 

 

I use both Promash and Beersmith2 and find the water to be pretty much spot on each time, although I tend to reduce more in the boil kettle.  Beersmith took a little longer to get right though as you have to set it up based on your brewery.  Maybe your software has to do the same?

 

Biggest tip I could give is a bit of stirring, not too much but 2 or 3 good stirs during your sparge would pay dividends.

 

Oh on thing I found useful was tasting the mash once it was done, work through it methodically and see if you find pockets of sweet grain that has been left behind (on a mash that you don't stir to start with).  I found that I had a pocket in the centre every time until I started to give it a stir, now its bland all the way through.

[Stu H]

Cheers for the input fellas!

I've been doing 2 batch sparges of around 10L each, and mashing in with 16L each time - it's obviously not enough water as I seem to always be under my target volumes.

I'm have a go with slower runoff rates this weekend and see how I go, along with a mashout infusion... Maybe I'll mashin with less volume to compensate. I like JT's idea of brewing a few beers of the same grist amounts to try and tweak the system.

For me it doesn't seem worth constructing a copper manifold: I don't have the tools to hand to build something like that, so in that case I'd probably be better off just buying a new mashtun with a fancy false bottom. I'd really like to get this sorted however so I can spend that money on a pump instead.

[Grant R Baker]

Ditto what has been said already.

 

I have been batch sparing for a few years now and don't have any problems... (99% ales though).

 

My mash strainer is just a SS braided hosed exterier from a washing machine hose pipe, I can upload a photo if you want, but you have most of it already.

 

The target temperature for batch sparging is about 72-77C depending on your brew.. so after mashing, draining, add your sparge water, stir, level for 15-30 minutes then run and drain  (run = drain into container until clear then retrun to /mash).

 

Also check you temp of your mash when draining.. if below 55C it maybe getting stuck do to increased thickness (viscositity) at lower temps.

[Andre Jaworski]

It may have been mentioned already but have you tried putting a coil of stainless steel wire inside the braid to stop it from being crushed?

[Stu H]

Yeah that's a good idea - any idea where I could get such a coil?

- And yeah, I think I'll have a go with a mashout infusion.

[Andre Jaworski]

We use it at work to lock wire bolts together on aeroplanes. It is just straight wire but you just wind it round something of the same diameter to shape it. If you have any aircraft technicians for mates ask them, they will be able to get plenty of it for free. Tell them you want 40 thou stainless lockwire.

Worst case scenario I could post some to you.

[Druid]

Make sure it's not an airlock.

When I first used a baided loop, I had a few issues with what I thought were stuck sparges until I worked out that the issue was an airlock forming at the high spot that is created in the braid just before the loop empties into the tap - the braid was being forced below the level of the tap by the weight of the grain, trapping air. The braid was not conducive to allowing air to bleed out of it through the mash very easily.

To solve it, before adding grain and strike water to the mash tun, I added just enough hot strike water to cover the braid and then tilted the tun so that there was no high spot at that point and opened the tap to allow enough to flow through to the hose - which I elevated for the duration of the mash so that the connection to the tap remained flooded - that way I could see there was solid fluid in the system when it came to running off.

[Stu H]

Ah good call bro! Do you batch sparge though? Surely this would drain right out at the end of each sparge?

[Druid]

If you are getting an airlock, it won't matter how you sparge because it will prevent any wort from being lautered/drained at all, let alone sparging to rinse the grains at the end of the lauter. 

It would start to dribble out then the airlock would be get compressed into the high spot and the flow would stop.  At first I blew backwards through the tap to clear what I thought was a stuck sparge - but of course this just blew more air in, compounding the problem.

I guess flooding the braid and the tap and making sure they stay flooded throughout the mash will at least eliminate an airlock as the cause if it isn't the problem.