Force batch sparging with a bike pump

[megaman]

I am new to all grain. So far, when my batch sparing slows down to a trickle I have been reaching in with a spoon and mixing up the bed to get it to flow more. I believe this is a mistake causing me to have cloudy beer and lower than desired efficiency.

My mash/lauter tun can be sealed. So If I close the lid - it wont drain out the bottom any more.

I am planning on taking the valve from a blown bike tire tube and attaching it to the lid of my mash/lauter tun. I would then hook my bike pump up to this valve and pressurize the air above the sparge water in the lauter tun. This would increase the hydraulic gradient through the grain bed and thus result in a larger amount of volume per time being expelled from the grains.

Any experienced all grainers see a problem with this plan?

 

[Yooper]

I don't understand at all! Why does the draining stop? When I batch sparge, I open the ballvalve and it drains all of the liquid out through the tube going to the false bottom. What kind of manifold/false bottom do you have? I don't think pressurizing your MLT will help if you've got a flow issue.

 

[Hammy71]

Won't you be forcing grain particles as well as runnings out of your MLT? Your correct you don't want to stir as you drain. Why not just gently tilt the MLT with the lid off and get your runnings that way?

 

[megaman]

see attached.

Basically, after 1 hour of single step infusion at 154 F, I pour in 170F sparge water and open the valve. I recycle the first gallon or so back into the tun, then I start collecting.

It seems to take a very long time. I thought it would take maybe 20 minutes. So I figure if I attach a bike pump I can create a stronger pressure gradient over the grain bed and get more flow through the bed.

 

[Yooper]

If it's taking longer than a couple of minutes, the problem must be with your manifold or false bottom. MY MLT drains in a flash.

 

[megaman]

well that is good to know. I'll try and figure out if my false bottom is failing.

If it drains quickly, why do people add rice hulls to wheat recipes?

 

[Yooper]

well that is good to know. I'll try and figure out if my false bottom is failing.

If it drains quickly, why do people add rice hulls to wheat recipes?

Wheat can be very gummy and sticky in large quantities, and the rice hulls are "filler" to keep the mash and sparge from sticking and gumming up the works.

 

[Benthic]

Wheat malt has no husk to act as a filter bed like barley malt does. Thus the addition of rice hulls to add some "filter media."

I agree with Yooper, if your MLT drains that slowly you've got some other issue. I'd concentrate on figuring out what that is and correcting it, rather than rigging up the bicycle pump solution (which would only be a band-aid anyway) you described.

Brian

 

[weirdboy]

It could also be that your crush is too fine/particulate.

The way to resolve a stuck sparge is to figure out why it's getting stuck. NOT force it anyway.

 

[chris200]

i say give it a try. I am curious if less time will result in less sugar? or if the pressure will result in more sugar?

 

[wilserbrewer]

Do you have a piece of tubing on the outflow from your MT. A 2-3 piece of tubing directed downward will siphon and suck the tun empty, creating a pressure differential akin to your bike pump idea. You sketch shows the wort flowing freely out the bottom of the tun, if this is true, you need a piece of tubing and gravity at work....MT on a table w/ the BK on the floor w/ 3' of tubing.

 

[wildwest450]

Malt conditioning will help as well.

-

 

[extra_medium]

How about opening the valve slower, if you open it up all the way real quick that initial surge will over compact your grain bed. slowly open the valve, let thr grain bed get set. then slowly increase the flow. every time you would disturbe the grain to fix the problem, I believe that you may be recreating it when you opened the valve again. (rice hulls will help too)
I is worth a shot, you could even try it with spent grains. you will get a feel for it. The OP said this was one of his first AG batches...might just be part of learning your setup.

 

[beerkrump]

False bottoms are great for fly sparging. Not so much for batch sparging.

The grain bed tends to compact if you try to drain too quickly. Adding extra pressure is just going to make this worse. It's just the nature of the beast. Either switch to fly sparging, do your batch sparging slowly, or get a maniflod.

 

[extra_medium]

Just thought I would offer this too...when i get a stuck sparge, I put a piece of tubing on the drain valve and blow into the MT. BE CAREFUL AND KEEP THE END OF TUBING HIGHER THE THE MT LIQUID LEVEL! When you clear the obstruction the MT will bubble (close the valve now) and then if you don't heed my warning, hot wort will start flowing out of the tube and into your face or where you are pointing the tube. Sounds silly, but after a few beers basic physics is easy to forget.

 

[November]

I had quite a few problems with stuck sparges while batch sparging. They all went away when I stopped opening the valve 100%. It takes a little longer to drain but my grain isn't compacting into an solid hockey puck anymore.

 

[megaman]

thanks for the advice - I'll try the slow open on the valve. I do have a hose connected to the valve - maybe it is too think and I should look at a thinner inner diameter. This will help keep the tube fully saturated with wort instead of air getting in through the end.

 

[megaman]

It worked - a valve opened ~25% flowed the whole time.

Thanks.