LOTS of Grain Getting Through False Bottom

[3 Dawg Night]

I "upgraded" to a BrewHardware.com false bottom in my 10 gal Igloo MLT. Today was my third brew day with it, and I'm getting tons of grain into the kettle; at least, I would if I didn't pass it through a mesh strainer first. This was today after my first runnings:

What gives? I'm grinding my barley malt at 0.033" and wheat at 0.025". This is an APA with 11 lb of a couple different barley malts and 0.5 lb wheat malt. I'd love to keep using the false bottom, because my efficiency is up 3-4%, but if this is the tradeoff, I'm going back to the bazooka screen.

 

[Deric]

Which false bottom? Are you using one of these?

https://www.brewhardware.com/product_p/biabbottom13.htm

 

[RM-MN]

It's likely that you haven't volaufed enough to set the grain bed or you have grain getting around the false bottom. Easy fix, guaranteed to work. Put a filter bag in the mash tun to hold the grain like BIAB people do. Then you can mill your grains finer without them getting through or around the false bottom and with that your mash effiiciency will go up so you can use less grain. The savings in grain on the first batch will pay for the bag unless you need a special size. If you need the special size to fit your 10 gallon mash tun it might take 3 batches to pay for the bag. Amazon.com: Brew Bags, Value 2 Pack Extra Large 26"×22" Reusable Drawstring Straining Brew in a Mesh Bag 250 Micron for Home Brewing/Fruit Cider/Apple Grape Wine Press/Nut Milk Equipped with spring type pull rope : Sports & Outdoors

 

[TheMadKing]

You're grinding way too fine. You should be grinding to about 0.045 to 0.05 unless you're doing BIAB

As long as you get uniform hydration of your malt and a slow sparge, you shouldn't need to crush that fine for efficiency in a standard MLT

A smaller crush size increases the rate of malt hydration, so conversion is much faster, but as long as you mash for sufficient time and sparge slowly (45-60 mins) it doesn't gain you anything except for in BIAB.

 

[3 Dawg Night]

@Deric This is the false bottom I'm using.

@RM-MN I've always vorlaufed when I had my bazooka screen, but Vorlaufing doesn't seem to matter with the false bottom; I'm still pulling grain at the end of the runnings. That leads me to believe it's a grind issue, as @TheMadKing states. I may try the grain bag if adjusting the grind doesn't help; although, at that point, the processes may be getting more complicated than warranted by any boost in efficiency, and I may go back to the bazooka screen.

@TheMadKing I mash for 60-90 minutes (depending on mash temperature), and I batch sparge. I found this article on crush size referenced elsewhere on HBT, and I like that it's backed by empirical data. I think I'll widen my gap to 1mm (~0.040 in) next time and see what that gets me.

 

[day_trippr]

Grain is getting around the FB. Here is the cure.

You're grinding way too fine. You should be grinding to about 0.045 to 0.05 unless you're doing BIAB [...]

I run my CK at .032" for barley and my old BC at .025" for wheat and oats...for a 3v2p herms...

Cheers!

 

[Bobby_M]

The crush is good. My false bottom crush is at about .032" and BIAB is .020".

I agree that grain may be slipping around the edges for one of two reasons or both.
1. The domed FB may not be sitting flat due to shipping tweaks. Put it on a flat table and see. Tweak back into position so it sits flat.
2. The cooler bottom is buckling a bit under heat.

If one of those are happening, the idea of an edge gasket like above would help make up for variations in the cooler bottom.


I'm assuming you stir right before the vorlauf and runoff. If that's true, give it 5 minutes to settle without any draining. Then vorlauf about 2 gallons and don't touch the valve after the last fill of the pitcher, just let it start flowing into the boil kettle.

 

[TheMadKing]

Grain is getting around the FB. Here is the cure.

View attachment 740554

I run my CK at .032" for barley and my old BC at .025" for wheat and oats...for a 3v2p herms...

Cheers!

Yep there's nothing wrong with that at all, as long as it's working for you. Most folks will see channeling issues through their grain bed or escaping grain through the FB either during recirculation or sparging when the crush it too tight. Reduced/uneven flow through the grain bed means uneven hydration and uneven grain rinsing which means a lot of sugar gets left behind.

If you batch sparge this is also less of an issue, but if you have flow through your grain bed, crushing small is usually more harmful to efficiency than helpful. The tight crush just improves the rate of conversion, which means you are more likely to be at 100% conversion well before 60 min. It doesn't necessarily improve the lautering efficiency and can actually be detrimental.

 

[WhoDatDad78]

Grain is getting around the FB. Here is the cure.

View attachment 740554




I run my CK at .032" for barley and my old BC at .025" for wheat and oats...for a 3v2p herms...

Cheers!

@day_trippr what is that gasketmade of or how do I get my hands on one?

 

[3 Dawg Night]

@day_trippr what is that gasketmade of or how do I get my hands on one?

It's all in the other thread. Click on the word "here" in @day_trippr's post.