Stuck mash

rcrabb22 · Joined: 23 Dec 2010 Posts: 462 Location: Illinois

I used my new Blichmann G1 20gal kettle with their false bottom for the first time yesterday after rebuilding my brewery. Not sure if this matters but I have new Chugger pumps with the center bore inlet fitted with a 3/4" to 1/2" reducer.

A simple pale ale, 76% 2 row, 19% vienna, 5% C20. I crushed at .045 and I mashed thin at 2qt/pound. I noticed about 15 min into the mash the fluid in the MT sight glass starting to decrease. The outflow from the return hose to the MT was just a trickle. I stopped recirculation and moved output connection from HLT return valve to the MT main valve to clear the dip tube of any possible grain clog. Hooked up hoses back to what they should be and the mash recirculation flowed full bore for about 5 min then slowed to a trickle again.

I flushed the MT dip tube as before 3 more times during the mash.

After the 3rd additional time and a few choice words, I got my mash paddle and proceeded to stir the grist. The majority of the grain had migrated to just above the dip tube. I redistributed the grain and by that time 75 min had past I decided to move forward with mash out. I raised the temperature of the HLT and start recirculation once again. Low and behold it flowed full bore for the entire MT ramp up period.

Unclear to me why I had a stuck mash.

**kal** · Posted: Sun Jul 31, 2016 9:44 pm Post subject:

Weird. Are you sure you milled at 0.045"? Some mills can come loose and you're milling differently than you think (though it's usually a looser mill, not tighter).

Kal

Tennessee · Joined: 04 Apr 2015 Posts: 116 Location: Tennessee

I assume you have checked all hoses and connection for minor leaks.

rcrabb22 · Joined: 23 Dec 2010 Posts: 462 Location: Illinois

rcrabb22 · Joined: 23 Dec 2010 Posts: 462 Location: Illinois

**kal** · Posted: Mon Aug 01, 2016 12:59 pm Post subject:

Tennessee · Joined: 04 Apr 2015 Posts: 116 Location: Tennessee

kkroeker · Joined: 08 Sep 2015 Posts: 19 Location: Oklahoma

I have experienced more than once the Blickmann plugging up even with the false bottom. may be because how close the tube is to the actual bottom of the tank. I have thought I might turn it a bit to one side after each episode, but forget to at the next session.

Most of the time it appears at the very beginning of the process for me. With my setup, I just backflush HLT water through the spigot a few blasts and then everything is fine.

I have a 2 pump setup where I dont have to unhook any hoses (that was when I made the biggest messes before). Its hard to explain, I have a "T" valve that I put on the HLT pump so I can inject HLT water for sparging through the HERMS coil or accept the Wart from the MT pushed by that chugger pump. If I turn off the MT chugger pump, and open a few blasts of the HLT pumped water, it will unplug the spigot and allow the liquid to flow freely. Then I just shut off the HLT water and turn on the MT pump and start the circulation flow as desired.

**kal** · Posted: Wed Aug 03, 2016 5:20 pm Post subject:

kkroeker · Joined: 08 Sep 2015 Posts: 19 Location: Oklahoma

Kal,

I honestly don't know right off hand what is it now, It has been set for quite a while and I haven't checked it recently. I know I set it initially for .039

**kal** · Posted: Wed Aug 03, 2016 6:03 pm Post subject:

You may want to go a bit looser if you're having issues, like around 0.045" or even 0.050". Good luck!

Kal

rcrabb22 · Joined: 23 Dec 2010 Posts: 462 Location: Illinois

I finished my 2nd brew using the Blichmann 20 gal G1 with their false bottom. I made Kal's Irish Red Ale. I did not have a stuck mash Smile

I did 2 things differently:

1) Mash return tubing coils around circumference of the kettle and about 3" past the Blichmann dial thermometer. I draped the tubing over the thermometer probe so it would not sink to the bottom of the kettle.

2) I put a SS worm clamp on the dip tube locking down the washer against the false bottom. I was wondering if I stirred the mash too vigerously the last brew and flipped the washer up exposing the slot and allowing grain to get below the false bottom.

Other than warm ground water and having to wait to pitch the yeast, all went very well.

**kal** · Posted: Sun Aug 07, 2016 1:59 pm Post subject:

Ozarks Mountain Brew · Posted: Sun Aug 07, 2016 4:43 pm Post subject:

you can add rice hulls I do and it helps also don't scrape the bottom when stirring, when doing so your just driving grain into the cracks clogging the false bottom up

**kal** · Posted: Sun Aug 07, 2016 6:18 pm Post subject:

For what it's worth, I scrape the bottom of my Blichmann false bottom with my stainless mash paddle (it was the swirls and scratches from ~7 years of me doing it) and I've never had a stuck mash. I also don't use rice hulls anymore even with beers composed of up to 60% wheat (huskless). I had forgotten to add the rice hulls one day when brewing a weizen and didn't notice the bowl full of rice hulls until after the brew day was done and I had cleaned up as I had it in another room... Wink

(So haven't used them since)

Kal

tae · Joined: 08 May 2015 Posts: 36

I had the same problem the other day when I did my first batch on the new system. I use 20 Gallon kettles and 2 chugger pumps. My recipe was a 16 gallon (into fermenter) Blue Moon Clone which had roughly 40 wheat malt plus oats. I found that the flow in my MT was very slow and I had problems raising the temp to the chosen mash temp, so i reversed and pumped backwards through the dip tube through the valve. That did it for a short while. I had to repeat 3-4 times. After 30-40 mins I had a decent flow but NOT impressive. I'm still wondering what went wrong? I know wheat can mess things up, but had my hopes high with my brand new Blichmann false bottom. Got 75% efficiency out of it. What should i do different next time?

Cheers

**kal** · Posted: Tue Aug 23, 2016 7:21 pm Post subject:

tae · Joined: 08 May 2015 Posts: 36

The recipe was roughly 50 % Pale Malt, 40 Wheat Malt and 10 % Oats. Mill gap is set at 0.045”. I was thinking about the Rice, but since I read that you never used them I decided to give it a try. I never used them either on my previous setup. Do you run the oats through the mill? I have always done it that way.

**kal** · Posted: Tue Aug 23, 2016 8:42 pm Post subject:

Flaked oats like this?: http://www.theelectricbrewery.com/flaked-oats

Flaked oats (or barley) does not need to be milled as it has already been rolled flat and toasted. Add it to the mash as is.

Kal

tae · Joined: 08 May 2015 Posts: 36

Yes exactly....