Mesh plate for BIAB

[Matplat]

I'm looking to get a mesh plate cut on the CNC router at work but have a few limitations to deal with.

I want to change my rig from malt-pipe recirc with sparge, to BIAB/no-sparge. The reason being that if I go BIAB, I can mash-in before putting children to bed and leave it without worrying if it's going to overflow, then come back to it later and hit boil. Currently I start after children are sleeping which means 11:30-12:00 finishes.

My good friend @tj2204 has been hitting some awesome efficiency targets with BIAB/no-sparge so at the moment there is no real disadvantage to loosing the sparge step, seems I must be sparging wrong anyway.

To convert to BIAB I need a mesh plate to hold the bag off elements and fittings, I will likely still recirc, for active temp control/step mashing. The router at work has 3mm and 6mm cutting tools, but they're reluctant to cut 5mm alloy with a 3mm bit, as the 3mm bits tend to snap if they do (I'm sure this has more to do with operator error than anything else), if I cut 6mm slots, the bag will obviously be less well supported, just to be conservative I would opt for 3mm, but if that's not an option, would there be much consequence to 6mm slots?

 

[mtb]

I'm interested in this for a few reasons.. just picked up a new malt pipe with the intent of increasing BH efficiency with BIAB. What efficiencies is @tj2204 getting?

 

[Matplat]

77% last time round! Even if I only hit 70% (compared with my current 75-77%) I would be happy given the time advantage it would give me.

 

[Lionman]

Cant you just mod the malt pipe to allow for safe overflow back into the tun if the flow is too fast for the grain bed?

Maybe some holes drilled around the upped edges of the malt pipe? I know the robo brew has a tube that runs down the middle of the grain bed for this reason.

 

[tj2204]

Yep, would've been 80% if I'd used my jerry cube rather than my cube cube as I would've collected an extra litre.

Currently have beersmith set up for 70% efficiency, but might need to change that soon as I can't remember the last time I got less than about 73%

 

[mtb]

Very impressive. I sacrifice a fair bit to kettle loss, with sparging I achieve 70% but leave behind about 4L

 

[Matplat]

Cant you just mod the malt pipe to allow for safe overflow back into the tun if the flow is too fast for the grain bed?

Maybe some holes drilled around the upped edges of the malt pipe? I know the robo brew has a tube that runs down the middle of the grain bed for this reason.

I did think about this, but doing away with sparging also saves time.

 

[Matplat]

I'm leaning toward 6mm slots in 5mm plate, pretty sure the bag won't fall through the gaps....

 

[Lionman]

I did think about this, but doing away with sparging also saves time.

I don't understand the advantage of a bag over the malt pipe. Cant you just treat the pipe as a bag and skip the sparge?

 

[Matplat]

The other advantage is grain quantity. At the moment I'm limited to about 6.5kg, going BIAB would allow significantly more.

You seem pretty emphatic that I shouldn't switch for some reason?

 

[Bribie G]

Using a bag with a slow hoist I lose very little to trub. The disadvantage of a malt pipe is that a lot of wort trapped in the grain is difficult to extract without a good squeeze.I guess that's why all the malt pipe systems require a sparge othewise the eff. would be woeful.

Once the bag is pretty well drained, squeezing from the top results in nice clear wort issuing from the bottom of the bag because it's going through a grain bed. Many commercial breweries actually do just that with a mash filter, leaving almost dry spent grain.

 

[Lionman]

I'm just trying to learn sorry. What method you use is your prerogative, but I like to know peoples reasoning. Nosey fucker I know! haha

My rig is part malt pipe part biab as I have a bag that is supported by a basket. Its interesting to fully understand what the limitations of this setup might be.

 

[Bribie G]

Nose away, Lionman, nose away...

I actually did a malt pipe way before the current crop of robograinguten devices when the only one out there was Braumeister. I used a Bunnings pail with lots of perforations drilled in it, plus a bottom screen and although it worked just fine for what it was, without a sparge I couldn't get the same extraction as using just a bag (or in my case a circle of voile in a hangman's noose).

A lot of the work arounds in BIAB can basically be solved by a good double pulley system off a skyhook so you always have that bag totally where you want the sucker to be.

 

[tj2204]

The other advantage is grain quantity. At the moment I'm limited to about 6.5kg, going BIAB would allow significantly more.

You seem pretty emphatic that I shouldn't switch for some reason?

You could do some pretty awesome high gravity brews with a brew bag and your current pot. I always struggle with high gravity brews in the urn as it's only 40l so the efficiency always drops more than I'd like, having 56l capacity should make that less of an issue even if you need a longer boil.

I'm 100% team brew bag.

 

[Stouter]

Got 5m of voile on special from Spotlight last week. It's much finer mesh than my current bag, and I reckon it'll cut my trub considerably. Wife is going to have a crack at making a teardrop bag for me. If this comes off well I'll end up with 5 bags for the price of one.

 

[Rambo]

I'm leaning toward 6mm slots in 5mm plate, pretty sure the bag won't fall through the gaps....

Back when I used a bag, I just used a pizza tray with bolts holding it off the bottom. The holes in that would have been about 10mm in diameter so you should be right with 6mm slots.

I'm no longer using the pizza tray if you want it?

 

[Matplat]

Back when I used a bag, I just used a pizza tray with bolts holding it off the bottom. The holes in that would have been about 10mm in diameter so you should be right with 6mm slots.

I'm no longer using the pizza tray if you want it?

Thanks mate! My kettle is pretty wide at 420mm, I imagine a pizza tray would allow the bag to spill over the edge?

Good to know about the hole sizes though, thanks!

 

[Rambo]

Thanks mate! My kettle is pretty wide at 420mm, I imagine a pizza tray would allow the bag to spill over the edge?

Good to know about the hole sizes though, thanks!

No worries. Can't measure the tray atm, but my urn is 380mm wide, and the tray would be about 20mm narrower than that from memory.