Recirc Mash Dramas

[razz]

That grey film during spraying is ok. Back to the problem, when you're stirring the mash (after it compacts) the silicon hose maybe allowing the edge of the FB to lift and cause a lot of mash to block the outlet. You said it has happened on three successive brews, what were the grain bills?

 

[Crusty]

What's your strike in volume, L/G ratio?
I found less than 3L/KG would be asking for trouble.

 

[Feldon]

Crush is standard beerbelly crush that they use for all their sales so I assume its suited to 3v as well as biab.

You sure? Your problem might be using a very fine BIAB crush in a tun with a false bottom.

 

[Ducatiboy stu]

You sure? Your problem might be using a very fine BIAB crush in a tun with a false bottom.

Could be...

Does the crush have a lot of whole husks in it.

 

[Filby]

Yer it could be that at the start I'm initially opening the valve up too quickly. I'll have to try pruning the pump before mash in and open slowly to begin with.

 

[Filby]

Strike volume is 2.7lt/kg.

Mash bills have been all barley and Crystal and some dark malts. No oats or wheat. Smallest was 5kg and largest was 7.5kg.

Beerbelly don't change their crush for biab or 3v, it's fixed at whatever gap. Amanda sold me a lot of the gear and false bottom at the same time as crushing the grain for me.

 

[fcmcg]

From what I've read on the herms thread , some blokes have up to nearly 4litres/kilo .
I myself usually have about 3 plus and never had a prob..
So maybe up the strike water volume..
I think your mash may not be "soupy" enough
Ferg

 

[Crusty]

From what I've read on the herms thread , some blokes have up to nearly 4litres/kilo .
I myself usually have about 3 plus and never had a prob..
So maybe up the strike water volume..
I think your mash may not be "soupy" enough
Ferg

I suspected that as well.
I think 3.5 to 4 l/kg & slowly opening the ball valve to just under half open will see things right.

 

[Ducatiboy stu]

I go for about 3-3.5ltrs/kg

 

[WarmBeer]

3.5lt/kg for me.

I stop the pump when I dough in, otherwise it does suck the grain bed down too hard, and will have problems getting the flow going again. After a good stir and adding my salt additions, its fine to start the pump again.

 

[Filby]

So an update. Done about another 8 brews on it.

Further things I have tried that didn't make any difference:

Really slow recirculation
Lots of rice hulls
Changed to a braided hose with multiple configurations
Used solid connections (no hose)
Using a grant and gravity feeding
Using 3.5lt per kg ratio
Stirring
Not stirring
Letting settle for half an hour

Had a mate come around with a esky and false bottom. Used that with the rest of my gear and it worked perfectly.

Yesterday, last brew of the day, had a very good grain bed and 94% efficiency into the kettle. Difference being 6lt/kg. Couldn't check clarity of the wort as it was a imperial stout.




Surely I don't need to use that ratio?

 

[real_beer]

These type of false bottoms can flatten out & push the pickup outlet against the bottom of the mash tun if the grain bed starts to compact too much. You could try putting something under the false bottom for support & also a stainless steel spring inside the silicon tube I set up my rims system to use the same whirlpool recirculation method as Sabco's Brew Magic system, explained in the video link below around the 7 min mark. It worked very well during a test & a later brew day. It's also possible to crush a lot coarser than most people like to accept, there's a video or article tied to their site where they recommend it, but you'll have to get off your arse & look for it yourself.



Cheers

 

[real_beer]

Are you opening your tap to quickly to start with? This will cause that sort of issue as the grain bed settles too quickly. Try cracking it a bee's dick to start with. I've got a tap teed in near my pump inlet to help with priming the pump and giving that initial flow somewhere to go.

This discussion might give a more precise measurement of the cracking opening involved: http://www.seabreeze.com.au/forums/General-Discussion/Chat/A-Bees-dick-metric-or-imperial/ Skid seems to be quite knowledgeable on the subject.

 

[dago001]

I have been having the same problem nyself lately, mainly due to a few system redesigns. In my case it is basically the pump pulling the grain bed down so that I get minimal flow and piss poor efficiency. I'm not one to worry too much about efficiency, but to drop from 80+ to 65 made me look into it a bit harder. Things I have changed recently that have improved my herms include
1 - mashing in and leaving the pump off for around 10-15 mins.(If I am step mashing I will leave it off for the first rest)
2 - Fire up the pump slowly to start off with, and once everything is going OK increase the flow.
3 - I changed my wort return as I found that this was/still is causing some of my channelling problems.

Most of my problems have started from when i purchased a new mill. I am currently crushing at 1.33mm, but I am getting better results lately. With the new mill, if I crush at 1.0mm I will spend all the mash stirring so as not to get a stuck mash. it seems to be acombination of a different crush and the pump. I'm still working it out.
Cheers
LB

 

[itmechanic]

LB I would open that gap up even further, I run around 1.5mm but have been up to 1.7mm with no dramas. Different base malts will also behave differently, Maris Otter for example seems a lot more friable with a lot more flour produced, weyermann munich has a much smaller grain size so behaves different in the mill. It can be hard to find a balance that works well for all malts, unless you want to change your gap for each (I don't as that takes about an hour of f#&king around on my mill). I get bang on 78% every brew.

 

[pk.sax]

I usually step mash, have noticed that the first 10-15 minutes is a pain to recirc, need to stir, don't know what, proteins?! seem to gum up and retain water. My fb is basically the insert pot inside bigger pot so fb collapse isn't an issue.

Once the mash is well underway I've never had a problem with recirc, even with the pump on full throttle.

Cut the surface of the grain up an inch deep or so with your mash paddle during the initial stages, basically a time thing, 15 minutes in there is no problem.

 

[dago001]

LB I would open that gap up even further, I run around 1.5mm but have been up to 1.7mm with no dramas. Different base malts will also behave differently, Maris Otter for example seems a lot more friable with a lot more flour produced, weyermann munich has a much smaller grain size so behaves different in the mill. It can be hard to find a balance that works well for all malts, unless you want to change your gap for each (I don't as that takes about an hour of f#&king around on my mill). I get bang on 78% every brew.

Thanks itmech. I have been opening the gap each brew day. I will go to 1.5 mm for the next brew (maybe today). Doesnt take long with the Millmaster Mini. I brewed yesterday and after a bit of stuffing about, I managed to get a good grain bed, with minimal chanelling. The wort return/sparge line is large part of the problem, but I am working that out. I managed over 80% with this brew.
Cheers
LB