Back to Shopping at NorthernBrewer.com

Mashtun draining issues

So with all my all-grain brews I have had trouble getting my mashtun to drain completely. There is a decent amount of dead space (using a 72qt for 5 gallon brews) but it goes beyond just dead space. At first I thought I was getting stuck sparges so I was disrupting the grain bed to get it to drain properly (resulting in lots of grain in my kettle) and yesterday even that didn’t seem to help. Some combination of moving and jiggling the drain hose and tilting the cooler seemed to do the trick. Each time it would bubble as if air wasn’t able to be displaced so I’m wondering if it isn’t the plumbing that is causing it.

My current setup is a 72 qt cooler with a bazooka screen threaded into a bulkhead. On the other side of the bulkhead I have a stainless ball valve. At the end of the ball valve I have a male quick disconnect to which I attach a hose with a female QD/hose barb. (pictures below). I also included a picture of my spent grain to see if maybe I am also crushing too fine.

Your grain crush looks like mine, Matt. I use a braid so can’t compare that. I generally end up with a cup +/- of wort that doesn’t drain, but I never thought that was excessive. Hope others chime in.

Do you have it tipped back away from the drain? If you don’t have a dip tube, you want to tip the tun toward the drain.

The fineness of the crush doesn’t really matter, it is the quality of the husks. With good husks, you can grind the endosperm to near flour. Do the husks look whole, but split down the middle, or do they look broken up into small pieces?I find that, with good husks, I’ll actually see almost a layer of empty husks lying on top of the crushed grain, prior to the mash.

The husks look pretty much whole but cracked open. There appear to be some that are crushed more than others but I really don’t think it’s my crush. I was definitely tilting the cooler and it appeared to only help when i moved/lifted the hose. There was a big gurgle/bubble when it finally started flowing again.

I don’t know much about fluid dynamics but was wondering if there was something in the shape of the tube and QD’s that could cause the flow to stop even if the grain wasn’t blocking the flow.

Almost sounds like the hose was crimped or blocked…

Doesn’t look like it in the photo but is it a multi layer hose? My food grade water hose has an inner sleeve that has apparently come apart from the outer sleeve and it seems to get crimped up and restrict flow sometimes.

[quote=“dannyboy58”]Almost sounds like the hose was crimped or blocked…

Doesn’t look like it in the photo but is it a multi layer hose? My food grade water hose has an inner sleeve that has apparently come apart from the outer sleeve and it seems to get crimped up and restrict flow sometimes.[/quote]

Yeah it was acting like it was crimped too but it wasn’t. I plan on switching to a hose braid and see if that changes anything but I would imagine that would be more restrictive not less. Unless there are just large chunks of grain clogging INSIDE the tube maybe?

Here is the tube I am using http://www.northernbrewer.com/shop/1-2- … ubing.html

You could be getting grain clogging inside the tube (or the valve, which is more likely), but to me it sounds like you might have a bubble that is stuck. Next time you drain, try holding the end of the hose up high when you open the valve, so that the wort would need to flow steadily uphill to get out of the tube. Then slowly lower the hose, making sure to let it fill evenly from the bottom up. When you lower it enough to see wort about to flow out, put it into your kettle.

Then, take a look at the shape. Is there any section of the hose where the wort is flowing up? If yes, you might want to lift your mash tun onto something higher while draining, because once the wort in the tun gets low enough that air can enter, it is going to stop flowing.

Matt I have the same mass tun and use a ss braided hose I bought at Lowes. I had to finagle it off its rubber/ plastic innerd, but it works really well. I bought it near the water tank section and it’s a foot in length. Removing the hose from the rubber/ plastic was annoying. It was almost like a Chinese finger trap! Switch and I bet it solves your problems.

You don’t have to dedicate yourself to the braid Matt. It might be an inexpensive experiment to try. I put a 1/2 inch long SS screw in the end with a hose clamp on it. That shuts the end off and helps weight it down so it don’t float around.

Is there any chance the bazooka tube is compacting?

[quote=“mattnaik”]The husks look pretty much whole but cracked open. There appear to be some that are crushed more than others but I really don’t think it’s my crush. I was definitely tilting the cooler and it appeared to only help when i moved/lifted the hose. There was a big gurgle/bubble when it finally started flowing again.

I don’t know much about fluid dynamics but was wondering if there was something in the shape of the tube and QD’s that could cause the flow to stop even if the grain wasn’t blocking the flow.[/quote]
It’s just that it looks like you are tilting the tun backwards, so the wort is flowing away from the drain, instead of forwards to make the wort flow towards the drain. That might just be my eyes tricking me, though.

It could be fluid dynamics. One thing about a siphon is that it needs to be a complete column to work well. If you have a drastic constriction at the QT and a wider ID in the tubing, you can fail to keep the tubing full of liquid, breaking the siphon. Of course, without a dip tube, you aren’t really depending on a siphon, you’re just draining, but a siphon might help to draw the wort down through the grain bed.

No they are pretty rigid and don’t lose shape.

No definitely just the angle of the camera.

[quote=“rebuiltcellars”]You could be getting grain clogging inside the tube (or the valve, which is more likely), but to me it sounds like you might have a bubble that is stuck. Next time you drain, try holding the end of the hose up high when you open the valve, so that the wort would need to flow steadily uphill to get out of the tube. Then slowly lower the hose, making sure to let it fill evenly from the bottom up. When you lower it enough to see wort about to flow out, put it into your kettle.

Then, take a look at the shape. Is there any section of the hose where the wort is flowing up? If yes, you might want to lift your mash tun onto something higher while draining, because once the wort in the tun gets low enough that air can enter, it is going to stop flowing.[/quote]

I’m not sure I fully understand what you are saying here but there is definitely no point in the hose where liquid has to travel upward. I use the same hose to drain my kettle and it’s even lower to the ground and I have no issues.

[quote=“mattnaik”]

I’m not sure I fully understand what you are saying here but there is definitely no point in the hose where liquid has to travel upward. I use the same hose to drain my kettle and it’s even lower to the ground and I have no issues.[/quote]
Two things: if the hose is draining downwards when you first open the valve, air can be thapped in the hose and slow the flow. And if the hose did have an upward slope at any point, late in the process air can enter and spoil the syphon you would need to fully drain in that situation. You don’t have the second part, but you may have the first. Try to purge your hose of air at the start of the sparge.

Do you think your QD has a good seal? Maybe it’s pulling air and causing an ‘air lock’ in the valve or hose?

I have nearly the exact same setup; same cooler, valve, QD’s (my hoses are now silicone though). Sounds a lot of like an ‘air lock’ Not sure how it is happening but I’ll see that big gurgle of air come out through the mash tun when I’ve got some air trapped in the line. It is far easier to diagnose with the silicone hose vs the opaque thermoplastic since I can see if I’ve got wort or air in the line.

Can you suggest any clear high temp food grade hoses? This would definitely go a long way to solving this issue

Pretty sure I got mine from http://www.brewhardware.com/ but I can’t seem to find it any where on the site. It appears Stainless Brewing has it. http://www.stainlessbrewing.com/Silicon … p_136.html Does make it much, much easier to see where I’ve got air in the lines which really helps when hooking up the pump.

I had problems with my first MT. I too used the bazooka screen. I had so much trouble with low flow using the bazooka. I bought a half inch supply tube and removed the stainless mesh, bingo no more problems. I kept everything 1/2". I too use the same hose you are using. I have since moved to using a copper manifold and like it better. I had no luck with the screen.

That’s good news. I was at home depot for some other stuff yesterday so I bought the items to build a stainless braid for my mashtun. Hoping this solves the issue.

Might be a little late if you already bought stuff from Home Depot. This is what I made for a cooler a few years ago. It is just CPVC, stainless screen from Ebay and stainless clamps. With the two “forks” and the stiff screen it never collapsed and always ran NP. All of the pieces are press to fit so it can be disassembled easily.

Back to Shopping at NorthernBrewer.com