First run on new HERMS -- BIG problems!

[jeeppilot]

I did my first run today on my new, basic HERMS setup. Also first time attempting a fly sparge. I have a 15 gal Megapot (BK), 10 gal Igloo (MT) with a false bottom and an old 8 gal pot for the HLT. I have a single pump with 1/2" lines, full-port ball valves and quick disconnects. The HERMS coil is a 25' 3/8" coil with 3/8" line from the output to the MLT.

I doughed in at 1.5 qt/L and started recirculating the wort. Quickly noticed I could not fine tune the rate of flow. It was either too much, or if I turned the ball valve on the pump output line to a low enough level, it would slowly just stop. Then if I opened it a bit, it restarted like it was wide open. (It was only half open). The wort never cleared, I don't think the grain bed ever settled.

When I went to sparge, it was a similar problem. Now, the clear water could be fine tuned to a trickle, but the drain to the brew kettle would slow to a crawl, then stop. Open it a little bit and it would surge, puke grain into the kettle, then run clear. It did this multiple times.

My efficiency didn't turn out as terrible as I imagined given the issues, 72%. Any thoughts on why I'm having trouble with fine tuning the flow rate of the wort? I assume it has to do with the false bottom/grain bed not setting/ etc as it happened only with wort and not with sparge water. Thanks!

 

[day_trippr]

The symptoms sound like pump head cavitation - except kinda backwards.
Usually throttling the pump output will stave off cavitation vs wide open.
Could you post a pic of your brew rig showing the pump orientation, and location relative to the other vessels?

Cheers!

[edit] Thinking longer, cavitation seems unlikely.
The simplest explanation might be that grain is plugging up the output of the MLT...

 

[GotPushrods]

It sounds like you're getting enough grain past the false bottom to clog the ball valve. What type of false bottom do you have? How is the seal and gaps?

For now you might try leaving it open long enough to set the grain bed and filter out those bigger particles before throttling back.

 

[acidrain]

It sounds like you're getting enough grain past the false bottom to clog the ball valve. What type of false bottom do you have? How is the seal and gaps?

For now you might try leaving it open long enough to set the grain bed and filter out those bigger particles before throttling back.

This ^

I run mine wide open for about 10 min to set the bed, and then control the output to the desired level no problem.
Make grain is not getting around the edges of the FB.

 

[oakbarn]

Rice hulls and set the bed. Vorluft!

 

[jeeppilot]

Yeah my false bottom may not be the greatest setup. I'm 99% sure it is the Adventures in Homebrewing setup. I got it included with the igloo cooler as a gift so I can't complain too much but I feel like there is nothing to hold it down and almost like it could float up. It is a bit smaller than the sides so it's more about keeping pressure on top of it.

I don't have a sparge arm (just laid the hose on top of the grain bed) but my understanding is disturbing the top of the grain bed isn't a big deal during recirc, only during sparge? Running it this way even at half open to keep it moving kept stirring up the top of the grain.

 

[Yooper]

You have a 3/8" OD HEX? I wonder if that makes a ton of restriction from your 1/2" tubing?

 

[RocketBrewer]

You're likely fighting small amounts of grain getting past your false bottom, I had the same problem. It becomes very difficult to fly sparge because small bits of grain clog your ball valve and when you crack it enough to clear, the flow is way to fast. I ended up getting a BIAB style bag and it made all the difference. Now I get no grain getting past the FB and in my plumbing, no clogs, no problems.

 

[jeeppilot]

Anyone with the Adventures in Homebrewing false bottom have any ways to seal it? I have heard about using a split piece of 3/8" nylon tubing around the edge but does that work?