Marbles as a Mash Filter

Has anyone ever tried using a bed of marbles in the bottom of the MT as a filtration? Any guesses on how well it might/might not work?

There was a thread here a few weeks back where someone had a SS screen in the bottom of a MLT but the screen was several inches off the bottom and a suggestion came up to fill that space with marbles. My idea just sort of came out of that.

 

I can think of much worse ideas. Try it.

 

Sounds to me like it would work, depending on how deep the bed of marbles is the grain should settle into it and filter as normal.

You would have to fly sparge.

 

In theory it would seem to work. I guess as long as the marbles are small enough.

 

Your actual filtration will be done by the grainbed itself, but this could be useful to hoist the grain bed of the bottom of your MLT if that's useful to you for some reason. Seems like a reasonable cheap alternative to a false bottom. Let us know how it works.

 

Huge mess to clean up. A couple years ago I made strawberry infused vodka. The jar had a spigot and I used marbles to avoid the berries clogging it. When finished they were a nightmare to clean and avoid going into the disposal. Careful!

 

If I were to try this (brew session coming up in 2 weeks) how would I judge it's effectiveness? Obviously a stuck sparge would be bad. What about efficiency? Low specific gravity of the wort pre-boil would be bad, I think. What else?

Tupperwulf, why couldn't I batch sparge this? Why the fly process?

 

Are you worried at all about even one of the marbles shattering in the heat? That's the only thing Id be worried about.

 

If you stir the mash up for a batch sparge, you would also stir up the marbles. They should certainly settle out first because they are heavier than the grain but you will get grain mixed in.

 

Then only potential problem is that marbles aren't made under food safe guidelines and they may have nasty stuff in them. Old marbles or foreign-made cheap marbles may have lead in them.

 

I'd be worried about using plain glass marbles. A quick google search turned up 6mm Pyrex beads, which should be much more durable and I wouldn't worry about bits of glass breaking off:

http://www.amazonsupply.com/corning-pyrex-packing-beads/dp/B004DGIDY2?ref_=bng_pf_B004DGIDY2

 

I second this. They did an episode on making marbles on dirty jobs....

They basically recycle glass, however there is no need to worry about sanitization or even using clean glass. The idea is anything they don't want won't withstand the heating process. They also use different materials to create the designs on the inside, some of which may not be safe to come in contact with food.

 

just don't loose them...

 

It sounds like far more work than a stainless steel braid. More cleaning (I always avoid this) especially.

 

Like the gravel bed in a fish tank. A lot of fish tanks have a false bottom with a layer of gravel over it as a filter. a pump pulls the water though the gravel. Now who's gonna be the first one to make it work for brewing. Hmmmmm

 

But why make it work?

How is it better than a stainless hose? Or a false bottom?

It just seems like a more difficult solution that won't even be less expensive.

 

It does seem like a cleanup pain, but you could use magnetic stainless (martensitic or ferritic) for the marbles, and empty the mashtun over a large magnet bar to catch the marbles, like a pavement sweeper. Or attach a steel plate to the bottom of the kettle so the marbles "stick" when you flip it upside down.

Stainless braid works well enough for me. Interesting idea, though...