Bad Kitty Brewery eBIAB

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schwartzr33

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I hope people find this documentation useful. First, I'd like to thank P-J for his designs, Kal for the vast amount of information, shuckit and DaSwede for their parts list, and jeffmeh for his explanations. This is a 240V/30A system, with a 20 gallon pot. We've done 4 batches on it and learn something new each time. I'll try to touch on things that have gone well and the things that still need work.

We had central air installed this year and I had an extra 240V/30A GFI outlet dropped in the basement for the electrical. While the electrician was there I also had him place a 120/15 GFI on the wall (under the light) and another one up in rafters for the ventilation.

The house is from 1927 and the brew pot is sitting on a concrete block, that I assume is a platform for an ancient washing machine.

The panel is pretty straightforward, Electric Brewing forum fare. With no kids in the house, the only modification I made to P-J's eBIAB drawing was to use a Auberins push button switch, instead of a key switch.

The inside of the pot is a work in progress. Perhaps the fourth time is the charm? On the first run, the bag got sucked into the pickup tube. 2nd try was a large tea ball, which worked well, until it got massively gunked up and stopped flowing. Third try was a stainless cooling rack--it's sharp edges shredded the bag (that was popular with it's creator, SWMBO) Try number four is pictured: pickup tube running through a small stainless strainer. This worked very well on the first attempt and will be repeated this weekend.

The main problem we are still having is temperature stratification. The bag really seems to block the wort circulation. When heating the mash, the temperature races up 6-8 degrees higher than our target, but some heavy stirring and sloshing of the bag brings things back down to where we want it to be. That is with full-throttle recirculation. The RTD is in the welded fitting (thank you Spike Brewing). I've done some more reading and have moved the RTD to the valve, we'll see if that helps to stabilize the temperature readings.

More to follow...

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The first photo shows the ventilation system and bar from which we suspend the bag for drainage. I'm pleased with the vortex fan, 6", 540 CFM. It seems to do a good job venting the steam, the tubing runs about 20' to the dryer vent. Still need to find a Y-connector so the dryer and ventilation tube can be hooked up simultaneously. The hood is a $5 plastic storage container from Menards. A little bit of condensation does drip back into the pot, so we put the lid on the kettle for the last few minutes of the boil.

The bar is black pipe and is suspended using plastic pipe strapping.

The Chugger pump is mounted inside another $5 container to protect the motor from splashes. That has worked really well.

Next is an action shot of sloshing the bag to circulate the wort. This works really well for mixing up the grains, but I wish it wasn't necessary for smoothing out the temperature stratification. We use a siphon clip to hold recirculation hose in place.

Then you can see my brew partner squeezing the snot out of the bag. It is also a good shot of the bag hanging on the carabiner.

Finally, that handsome devil is Harold, the eponymous bad kitty.

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Yes, we're still getting stratification even with recirc. It may be because the RTD is mounted at 1" from the bottom, so in close proximity to the element, and the bag/grain keeps the wort from distributing. However, this weekend we are going to try it with the RTD mounted in the valve. If that doesn't work, it maybe time for Plan E, which could be HERMS.
 
would having just some sort of false bottom work in this thing?

It is a 20" pot and I've had a hard time finding a wide, reasonably priced, stainless solution. I'd welcome suggestions. The 14" cheapo cooling rack I tried had sharp edges and shredded the first bag.
 
Nice job. I have an electric brewery and tried BIAB for the first time a week ago. What do you do to keep the mash at temp? Are you heating with the element while mashing? What about the bag touching the element? I wrapped the pot in a blanket, but still lost several degrees. I had to raise the bag, heat the liquid, then drop the bag back in. Just looking for a better way to maintain mash temp. Thanks!
 
Nice job. I have an electric brewery and tried BIAB for the first time a week ago. What do you do to keep the mash at temp? Are you heating with the element while mashing? What about the bag touching the element? I wrapped the pot in a blanket, but still lost several degrees. I had to raise the bag, heat the liquid, then drop the bag back in. Just looking for a better way to maintain mash temp. Thanks!

Well, the PID is suppose to keep the mash at temperature, using the element, but that's where the difficulty has been, with the uneven temperatures between the pot and grain. That's why we've been sloshing and stirring, which seems to work well, but it is not the set it and forget it solution I was hoping for when I designed the system. The bag versus the element is not an issue for me. I read a bunch of posts and got the impression that the bag would not scorch, especially with a ULWD element (wavy Camco). This has proven to be the case, the bag floats around the element and the element doesn't get that hot anyway. I'd say leave the bag in and see how it goes. My experience is that getting an even temperature is more of a worry than scorching the bag.
 
I have been using a round steamer rack for years, with no problems regarding sharp edges and the bag. I don't recirculate however, so perhaps I would have had a different experience if the suction was forcing the bag against the rack.

The one I have is similar to these. http://www.webstaurantstore.com/3189/steamer-racks.html

Thanks, Jeffmeh. These are very similar to what I tried, but in retrospect, mine had very obvious sharp edges. The shredding problem wasn't the recirculation, but the aggressive sloshing. I think I have the bag-suck issue figured out with the strainer--now just gotta figure out how to get even temps.
 
I do find it strange that you are having temperature stratification issues recirculating from the bottom to the top and through the mash. You will certainly lose some heat in the tube, so if you have it any longer than necessary you should probably shorten it. You could also wrap it in some pipe insulation. If the bag is too fine and not draining, then I would expect it to be obvious with vacuum issues with the pump, and that you would see a rise in the water level close to the volume not contained in the bag. You could experiment more with the flow rates as well.

Is the temperature uniform inside the bag, but different from the temperature below it, or is the temperature not uniform inside the bag? If the former, you can adjust the PID to account for the difference. If the latter, I would expect the issues to be from side to side, so you might want to try using some type of manifold for the return, like the loc line circle nozzle http://www.amazon.com/dp/B00065UDB0/?tag=skimlinks_replacement-20. If the issues are from top to bottom, then I'm stumped if you are recirculating wide open and getting good flow.

By all means keep us posted as you work through this.
 
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Also, having the lid on during recirculation should certainly reduce heat loss.
 
jeffmeh
I too was having large temp differences in my biab recirculating system.My temp probe was in the return tee in the lid,I then moved it to the pot wall under the cake rack false bottom and it was better .I know have it in a tee at the valve out of the pot and find that the mash gets about 1.5 degrees celcius(sorry about metric but i am in greece)lower than the temp under the bag.
I still dont know what is correct having the temp under the bag at the required temp and the grain bed slightly lower or the grain bed correct and the wort near the element higher
any suggestions appreciated ,sorry to highjack the thread
Paul
 
I think the problem has to be where your temp probe is located. Try changing it to a T on the output of your kettle and you shouldnt have any issues. This way it is taking the temp of the hottest liquid which is then recirc to the top of your mash.
 
Schwartz - Wow. You have put the bag on the element? I have the same wavy Camco element, but it scares me. Was it a 5500 on full?
Didn't burn, huh. Might try it, just a little scared.
 
Schwartz - Wow. You have put the bag on the element? I have the same wavy Camco element, but it scares me. Was it a 5500 on full?
Didn't burn, huh. Might try it, just a little scared.
Yeah, we haven't had any problems with the bag on the element. When I first started planning the build, I thought a false bottom was a requirement, but later I read several posts that said it wasn't an issue. I'm not sure if this logic is 100% accurate, but the element is not on full blast for very long when mashing. You heat your strike water without the bag in the pot. After that, while the bag is in, the element is only on for brief periods of time to keep the wort at temperature. And there is a lot of water to protect the bag. I think I've read that the ULWD nature of the element is helpful in protecting the bag, but there are others here who can explain that better than I can.
 
Let's start with the things that went well today. First, I'm happy to report that putting the RTD in the tee worked well. The temperature was much more stable. We still did some sloshing and stirring, and occasionally turned off the element, but we did those things much, much less than in the past. Overall, the mash temperature was much more consistent with a lot less fussing. The PID did run a few degrees high, so eventually I'll need to calibrate it. Also, we used some fresh hops that a friend had grown and we put them in a paint strainer bag with a zip tie to keep them contained--that worked like a charm.

Things that didn't go well: Unfortunately, we had a major disaster with the bag. During the mash the pump wash running on full and it sucked the bag down with enough force that it crushed my stainless strainer (you can see the strainer in its better days in my OP), that choked the pump, and because the bag was immobilized it.... wait for it....... scorched holes in the bag! We ended up with probably a cup of loose grain in the wort, which really mucked up the plate chiller. Not a good finish to the brew day. Fortunately, the wort didn't taste burnt (due to the melted bag), as some on HBT have said. I am now looking for tips on how to get the melted nylon off the element. I'm thinking of light sanding with very fine sand paper. Thoughts?

So, do elements melt bags? Well, yes they do, though perhaps only under certain circumstances.

So, where to go from here? I see three options:
1) Patch the holes in the bag and get the Blichmann Hopblocker. And assume the bag won't melt because it won't get sucked into the pickup tube again.
2) Fix the bag and go with a custom made false bottom.
3) Ditch the bag and go with a custom made basket, a la wobdee https://www.homebrewtalk.com/f11/my-one-vessel-ag-system-380656/

I would welcome your feedback. Thanks.
 
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Hey schwartz,
Wanted to chime in and give you a little insight on my eBIAB system and experience. I have a 22 gallon Bayou Classic Kettle with a weldless T sightglass and temp probe and a 3 way ball valve. Also, I have a ULWD 5500W heating element. My bag is placed directly into the kettle and does not have a shield from the heating element. I do not have a pump, but do not have problems maintaining mash temps. My trick is to keep the lid on during the mash and stir occasionally to distribute heat. Every 15 minutes or so (when I see the temp drop) I will kick the element on and stir the mash vigorously. I like the recirc idea, but feel like it would create to much pressure with such a fine bag which is used for BIAB. I have come to the conclusion it is cheaper and less hassle to go without.

As mentioned again, I believe as long as you use an Ultra Low Watt Density heating element you are fine with leaving the bag on the heating element, but make sure to stir vigorously! I have made 6 batches (11-14 gallon) with this system and have yet to have any problems. Hope this helps.
 
I like the recirc idea, but feel like it would create to much pressure with such a fine bag which is used for BIAB.

Chris, when you BIAB mash is your water to grist ratio high or low. I am certainly not an expert here, just trying to learn. If the ratio is high, lots of water, what pressure are you referring to?
 
I have almost the same setup as Chris: 26 gal kettle and make 10 or 15 gal batches, no Temp controller, no pumps, no bag shield, and have attached uhaul moving blankets via bungee cords for insulation. I grind the grain into dust using a corona mill.

I just heat water to temperature i am looking for (+6 degrees to account for grain addition temp drop) add grain, mix, add lid and add a blanket on top. I used to stir every 20 min but don't even bother doing that anymore. With stirring, I lose 3 degrees over the hour, with setting and forgetting, I lose 1-2 degrees over the hour. Then I pull bag using a pulley pulley and let it hang and drain until it stops dripping. I end up with 80-84% mash efficency. Afterwards, I strain trub as its going into fermenters using strainer and a piece of swiss voille.

There are a few problems with pumps and trying to stabilize the mash temp:
1) The pump pulls all of the water from around the element and compacts the grain/bag onto the element. This insulates the element and can cause element/grain or bag to burn.

2)A lot of heat is lost due to liquid flowing through tubes and pump.

3)The temperature at the sensor will be different then the temp at the element.

4)The more "stuff" (baskets, element shield, hop screens) you put in the kettle, the more difficulties you will have with temp stratification and having the element burn.

I think we were just trying to keep a kettle full of liquid and grain at the correct temperature I think recirc would be perfect, but the bag really causes problems..

I think pumps are better used for cooling and/or filtering (jamil'o'chiller, whirlpooling, filtering using the brewhardware trub filter, plate chillers etc) But mashing... no so much.

Edit: For a 60L 1.050 batch I use 12.5 kg of malt, 85L of water all added at mash-in.
My boil off is about 15L For my 90 min boil. I don't bother with mash-outs.
 
I think if we were just trying to keep a kettle full of liquid and grain at the correct temperature I think recirc would be perfect, but the bag really causes problems..

I think pumps are better used for cooling and/or filtering (jamil'o'chiller, whirlpooling, filtering using the brewhardware trub filter, plate chillers etc) But mashing... no so much.

Are you suggesting that if one wants to be more precise with mash temperature then the traditional 3 kettle system out performs the BIAB? I am trying to figure out if I should build an electric BIAB or an electric traditional 3 kettle arrangement. I have looked at the electric brewery information and with the HERMS coil it seems they can keep the temperature within a degree by recirculating the sweet wort through the HLT.
 
No sorry, I am just strictly referring to electric BIAB systems. In electric BIAB systems I personally don't think using a pump works well for keeping mash temps.

3 Vessel systems do not use a bag and are a totally different beast.
 
So, where to go from here? I see three options:
1) Patch the holes in the bag and get the Blichmann Hopblocker. And assume the bag won't melt because it won't get sucked into the pickup tube again.
2) Fix the bag and go with a custom made false bottom.
3) Ditch the bag and go with a custom made basket, a la wobdee https://www.homebrewtalk.com/f11/my-one-vessel-ag-system-380656/

I would welcome your feedback. Thanks.

I think you are really close and one minor change would make a huge difference. I have ab=n elevated rack that fits into the bottom of my kettle that keeps the bag off of the bottom. There are many BIAB threads that talk about this. It does solve several issues. It stops your bag from contacting the burner and it stops the bag from getting sucked intl your recirc pump. It creates an environment similar to the 3 kettle MLT arrangement.

If you brew like me, a very high grist to water ratio, moving the bag a few inches from the bottom of the pot does not increase the grist ratio that much and you would still be over the recommended ratio that traditional MLT brewers have. So your sweet wort is still good.

Then just drop the flow of the recirc pump to the minimum that will keep the temperature close to constant. The recirc water flows over the grist in the bag so you don't need to mix any. To do this you will need a valve after the pump.

I think these two changes will make all the difference to your process.

Edit: And keep your transfer tubes as short as possible to reduce heat loss.
 
Thanks for all the great feedback and ideas. I think I will experiment with both a) insulation, lid on, no recirc and b) a false bottom/pizza screen.

One question on the pizza screen.... Is anyone concerned about the screen being made from aluminum? I need a 16" screen and have has trouble finding a reasonably prices stainless option, but large, cheap aluminum ones are plentiful. I'm far from an metallurgy expert, but don't we generally try to avoid aluminum? Maybe if I only use the screen for the mash and remove it before the boil there wouldn't be any issues?
 
Aluminum is fine, although the pizza screen will likely not take much weight without bowing. You should boil the aluminum pizza screen once for about 30 minutes before you brew with it. This creates a dull oxidization layer that you should never scrub off with abrasives or caustics. That's what separates the aluminum from the food or wort.
 
Chris, when you BIAB mash is your water to grist ratio high or low. I am certainly not an expert here, just trying to learn. If the ratio is high, lots of water, what pressure are you referring to?

I add all the water for the brew at once, no sparge. I would assume there would be added pressure on the grain bed from the water above, but I could be completely wrong.


As far as the pizza pan, there is no reason to add this. The grain bed is suspended in the kettle. If you put a 30lb grain bill in there, don't think that is 30lbs of pressue weighing down on the heating element. The grain is suspended in the water. Pizza pan is just extra equipment complicating the simplicity of BIAB. BIAB = Bag + Grain + Water. Nothing else is needed. I receive on average 35 (out of 50) on my beers in competitions, nothing medal worthy yet but better then your average bear!
 
Just food for thought here. My system (b4 adding a recirculating pump recently) will pressure lock when draining water/wort from the spigot with the lid on. The Speidel Braumeister system recirculates the entire mash. The Speidel Braumeister also has slots made into the lid! So with our type of BIAB systems with the lid on, you will either need to drill a small hole for air flow or crack the lid slightly during recirculation in order to keep the bag from "pulling" toward the outlet.
 
Here is an update from yesterday's brew day, Our system is definitely getting more stable.

As you can see from the photos, we added Reflectix (2 layers) to the brew pot. Not surprisingly, this provided enough insulation that the element did not need to fire that often. We also made a hat for the lid. We put the recirc hose in the center of the mash (had previously been putting it on the side, opposite the pickup tube). I think this significantly helped recirculate the hot wort. The next step will be to drill a hole in the lid, so the lid can be all the way on.

The other big improvement was the 16" aluminum pizza screen. I made legs for it with 2.5" machine screws, washers, and finishing nuts. $2.25 per nut! I am relieved to say the screen did not collapse, though the screen is clearly deformed after one use. The legs were placed strategically around the element, and above the pickup tube. The big gaps in the spacing of the legs is because the screen rests on the fittings for the element and the valve. The tabs are a stainless brace, cut in half, to wedge the screen against the sides of the pot, to keep the screen from moving side to side.

The most interesting finding was that we had a vacuum lock throughout the mash. That is presumably why the screen is deformed. We had good luck with the pump running at about 50%, the bag was firmly stuck in place, but we did not drain all of the wort from underneath the screen and we did not have cavitation. Yambor44, the lid was more than a little open. I think the issue is the concrete oatmeal created by the fine mesh bag and the double crushed grain. I wonder if a slightly more coarse bag would allow the wort to flow more easily?

We managed to hold the mash between 151-153 pretty easily, though still with occasional stirring, albeit less stirring than before. We still need to move the RTD to the pump output, to minimize the temperature differences. As it stands, the SV needs to be a few degrees higher than our target mash temp.

Finally, I think we will ditch the pickup tube. I'm not sure it is doing anything except making it easy to pickup trub. We haven't had great luck whirlpooling, but the gunk does settle to the bottom pretty quickly. I'm thinking that without the tube, the valve will sit high enough above the trub after letting it rest for 15 minutes. There's always one more thing to experiment with...

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Hi Schwartz,

I have a setup like yours seen here -

https://www.homebrewtalk.com/f170/first-run-ebiab-w-pics-410168/

I have too struggled with temp fluctuations and pump recirculation issues.

I got a bigger weave bag and went to a single grind (was grinding 3x before ebiab) and used a sparge arm connected to my pump.
I was able to get 1 degree of change between my PID temp and my temps at the top of the kettle.
But I can not leave my mash alone for fear of the dry fire (and I did already ruin one batch and element with a dry fire).
My original thought was I could leave my setup for an hours while mashing and keep spot in temps.... so far that is FAR from the case.

I am have gone back to double grind and not pumping.
I stir every 20 mins or so and insulate the kettle with a blanket, but temp will still stratify by 4-5 degrees after some time.

I have a stir motor on order, and am hoping this will solve all my issues.
As you know... stirring will keep consistent temps and I will have NO dry fire issues.

Not many eBIAB guys seem to use stir motors though?

PJ has great pics of the motor he uses.

any way... thought I would share...
Nice build and good luck.

thanks Kevin
 
The trials and tribulations continue. The first photo shows the solution we came up with for managing the condensation that drips back into the pot from the ventilation system. We suspended the pot lid for the last 5 minutes of the boil using a bungee. This actually worked really well for keeping condensation from the fan out of the pot. In the future I think we can position it with a slight tilt, beyond the side of the pot, so condensation from under the lid falls to the floor, instead of into the pot.

It's good to start with a positive right? The second photo shows what is left of the pizza screen false bottom. It worked well on the first brew day, but yesterday it failed catastrophically from the weight of the bag. The screws and washers literally tore the aluminum to shreds. Fortunately the bag only got a couple of small holes.

To close on a positive note (sandwich), despite this setback, we had a great brew day. Temperatures were the most steady yet and we had 83% efficiency with a 4-step mash.

Next plan: calling Chad at Arbor Fabricating.

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OK, how about trying a bag custom-fit so that it cannot reach the element? :)
 
I bought a perforated pizza pan and mounted stainless steel bolts, washers and lock nut through it to create a false bottom. It works great and doesn't deform.
 
jeffmeh said:
OK, how about trying a bag custom-fit so that it cannot reach the element? :)
That could be an elegant solution, thanks! Ordered a wilserbrewer bag last night, 2-3/4" shorter than the height of the pot, to keep the bag away from the element and the pickup tube. I'll keep you posted.
 
Regarding temperature stratification, it's my opinion, after personal experience, that the PID controllers are not well suited to slow changing systems with lots of thermal mass. The PID over corrects and then it takes a while to cool off and you get these wild swings. If you operate the PID in manual mode and start around 50% and then bump up or down to get your mash in temp you'll find a percentage that works consistently. I run the same PID I use on my brew controller on an oven and it keeps it +\- 1F . By coincidence, the oven has a 5kW heater in it. It would probably work better on a RIMS where the temp sensor was directly down stream of the element. It would tune up better because it could sense and correct faster.

One other thing I did was spread the element out some so it wasn't heating in such a concentrated area. If the fixed part of the element is at 6 o'clock, the free end is bent out to 4 o'clock.

One other suggestion on the PID is to run 100% until you are within 10-20 deg of you mash in temp then turn it over to PID control. That's how the Braumiser Arduino code is written.
 
Thanks for the bag order! I shipped yesterday. Just my opinion, but the crushed and mangled pizza screen above was likely caused by the pump suction due to a clogged filter bag, not the weight of the grain. I have no idea what bag material you are using, perhaps turn the pump down. The only time i realized a reduced runoff through a bag, I had a percentage of wheat in the grist. Things I might consider...

1. Throttle back your pump, a trickle should be all you need in a closed system with insulation on the kettle.
2. Using slightly coarser filter / bag material / or less flour in the crush / or use some rice hulls.
3. wrap a piece of pizza screen around the element to make an element guard...not that I think the bag is going to scorch...just a bit of insurance.
4. Heavy duty false bottom.

Good luck solving your issues! You have accurately pointed out why I have neglected to build a fancy E-BIAB system and prefer to keep it ghetto simple making manual temp adjustments and just wrapping the kettle in a large comfortor.

What size batches? I would imagine that large 20 gallon kettle provides a large cooling surface area ratio if only doing 5 gallon batches.
 

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