Help me fix/regain trust in my ebiab!

[pmaster]

I have the following setup:
13gal kettle
2x 1800w elements controlled by a PID
1x pump connected at the bottom for recirc, which flows back on top via a hose that is clamped on the side of the kettle.
1x brew bag
1x false bottom

I've done about 10-12 batches with this setup, and things have gone mostly well. However I've had some major issues for about 3 of these batches.
1. My temps are nowhere near stable. My PID, which takes the reading at the elbow where the pump is, is often 8-10F higher than the temp elsewhere in the mash when measured with a thermometer (both my PID and thermometer are calibrated).

2. I've now ruined 3 batches which turned pretty bad with a burnt/smokey taste. I realized yesterday it was because the element was briefly exposed to air, probably because the pump removed the water underneath where the bag sits on the false bottom, and the wort was too thick to filter through the bag back underneath.

It would seem that these issues happen more often on higher gravity beers, given that the wort will be thicker and there will be more fine dust to obstruct the flow (I get my grains milled by my LHBS).

Its really frustrating... I tasted yesterday's wort after a long brew day for a 6 gal batch and it tasted like an ashtray.

Any advice???

I'm tempted to get rid of the pump and just stir manually on a regular basis, but the pid is connected to the recirculation system, I'd have to modify the kettle or figure out another way. Plus I still have the feeling there will be a huge gap in temperature underneath the bag.

 

[Boydric]

What is the watt density on you elements? Are they low watt density?

 

[atoughram]

What is the watt density on you elements? Are they low watt density?

X2 - those dont look like ULWD elements..

 

[pmaster]

Hmm I have no idea to be honest. I bought them at a small local shop last year, they were pretty much standard heater elements. I would suspect they are not, since if I understand correctly a low watt density disperses the heat throughout a larger surface but a lower intensity?

They're only 120V 1800W elements, so already its a lower intensity than a 240v one I guess. I'm pretty sure I scorched my wort because air was underneath the bag, I briefly smelled something burned, and some air was coming out between the bag and the kettle, making a flop-flop noise (its hard to describe a noise! lol). Wouldn't the result have been the same with a different element?

 

[d3track]

Is that a pvc tee?
Do you have a valve on the output of the pump?

 

[Mirilis]

Those are way to small to be low watt density elements

These are the elements I have in mind. 120v 1650W.. you can see the difference. Higher density elements can scorch wort and give the flavors your describing... The PVC T is a bad idea as well... Cpvc can hold higher temp but I'd at least replace that with brass.

 

[schiersteinbrewing]

Ditto what they said. Replace PVC with brass or stainless steel, valve on output of pump, replace your elements with ULWD ones.

Also what crush size are you using on your grains? I had issues with a stuck mash like your taking about crush size or rice hulls will make a huge difference. I am running a .045-.050 on my crush.

You also may only need to run one element to maintain your mash temps.

 

[pmaster]

Good eye on the PVC Tee. The picture I showed is actually a bit old from when I first put together the kit, since then I've switched to a brass tee since the PVC one obviously couldn't stand the heat.

I'll look into replacing the elements for ULWD ones, I'll have to see about their length though....if I put two of these it might be too long to fit since they are both aligned.

I don't have a valve on the output of the pump, however I was restricting the voltage through a PWM, and also restricting the flow with a clamp. I'll look into getting a valve but the issue about the difference in temperatures will still be present. Has anyone else observed this? The mash in the center was about 140 yesterday, while the temperature on the output of the recirc was at around 150F.

 

[pmaster]

Ditto what they said. Replace PVC with brass or stainless steel, valve on output of pump, replace your elements with ULWD ones.

Also what crush size are you using on your grains? I had issues with a stuck mash like your taking about crush size or rice hulls will make a huge difference. I am running a .045-.050 on my crush.

You also may only need to run one element to maintain your mash temps.

Yeah I actually just use one element to maintain the temps, I disconnect the other.

I have no idea concerning the crush size, I take what they give me at the LHBS... I guess I could always ask to get a coarser crush.

Its funny you mention rice hulls, I actually used some yesterday, halfway through the brew. It did seem to help, but I'm not 100% sure. It seems to be it would be pointless to use when you already have a bag, but if others have used it with success then next time I'll use them at the beginning of the brew.

Do you use rice hulls when doing BIAB?

 

[pmaster]

Those are way to small to be low watt density elements

These are the elements I have in mind. 120v 1650W.. you can see the difference. Higher density elements can scorch wort and give the flavors your describing... The PVC T is a bad idea as well... Cpvc can hold higher temp but I'd at least replace that with brass.

Do you know by any chance if ULWD elements are all folded that way?
I mentioned I had burned out an element before and replaced it. Its not shown in the picture, but I replaced it with a folded element like the one you just showed. Is there a way to identify an ULWD other than at the time you buy it?


Sorry I can't go take a picture of the kettle right now as I put all of the stuff away until next brew day .

 

[Mirilis]

Its a measure of watts and inches.. if there is 5 inches of element and it's 1000W then there's 200 watts per inch. If the element was 10 inches then it's only 100W per inch.. make sense?

Shoot for around 50 watts per sq inch

 

[Mirilis]

I'll look into replacing the elements for ULWD ones, I'll have to see about their length though....if I put two of these it might be too long to fit since they are both aligned..

They bend.. just be careful and give them a slight bend so they clear

 

[Mirilis]

120 v element

These are the ones I used. I soaked the element part in starsan for an hour and scrubbed them down to the copper sheathing

 

[pmaster]

Its a measure of watts and inches.. if there is 5 inches of element and it's 1000W then there's 200 watts per inch. If the element was 10 inches then it's only 100W per inch.. make sense?

Shoot for around 50 watts per sq inch

OK that's what I thought, so I guess I'll just have to change one of my two elements then.

Now if I can figure out the issues concerning the difference in temperature between top and bottom. I'm guessing if I restrict the pump flow further it will help with the bottom draining and exposing the elements.

 

[Mirilis]

My guess is probe placement. I put mine on the return through the lid. Ive seen them mounted on the outflow and no reports of problems though... Another thing is maybe your not circulating fast enough.

Try putting your pump where the probe is and put the probe where the pump is

 

[Powercat]

I had the same problem until I purchased one of these. The false bottom restricts the flow too much. The larger openings in this one will allow a proper recirculation. https://www.brewhardware.com/product_p/biabbottom15.htm
They are available in different diameters.

 

[pmaster]

I had the same problem until I purchased one of these. The false bottom restricts the flow too much. The larger openings in this one will allow a proper recirculation. https://www.brewhardware.com/product_p/biabbottom15.htm
They are available in different diameters.

Hmm, I'll look into changing that as well then. The false bottom I have is not too bad, maybe I'll just cut some parts of it off, or get a wire-one like on your link.

Thanks for the tip. You noticed a big improvement after doing that?

 

[Powercat]

tremendous. highly recommend it.

 

[Powercat]

Check out this thread.
https://www.brewhardware.com/product_p/biabbottom15.htm

 

[schiersteinbrewing]

I'll look into replacing the elements for ULWD ones, I'll have to see about their length though....if I put two of these it might be too long to fit since they are both aligned.

In a dual 120v build I did, I made the same mistake on aligning the elements. Not a huge issue, I just CAREFULLY added a slight bend to them then they both fit.

Sorry just realized someone beat me to the comment.

 

[Powercat]

Sorry I posted the wrong thred. Try this one
https://www.homebrewtalk.com/showthread.php?t=577383

 

[timdillon36]

Make it as hard as you want but with BIAB it really is as easy as hit strike temp, stir in grain, remove grain. It only takes 20 min from the time the grain hits the water.

 

[pmaster]

My guess is probe placement. I put mine on the return through the lid. Ive seen them mounted on the outflow and no reports of problems though... Another thing is maybe your not circulating fast enough.

Try putting your pump where the probe is and put the probe where the pump is

Actually I measured the temperature at the output, by placing the thermometer under it, and it was indeed much hotter there, so I guess there really is a difference in temp between the middle of the mash and the bottom where the elements heat and the recirc is going. Its normal after all, but in my case it seemed a bit extreme. Although I haven't noticed as big a difference when doing lower gravity beers...

 

[schiersteinbrewing]

Just out of curiosity about how much water are you using for your mashes?

 

[pmaster]

Just out of curiosity about how much water are you using for your mashes?

I believe i was at 7.8 gal for 16lbs of grain for a 6 gal recipe

 

[pmaster]

I still have one element to change, and I got my new false bottom today (ordered this: http://www.ebay.ca/itm/351788086703?_trksid=p2060353.m2749.l2649&ssPageName=STRK:MEBIDX:IT)

I should be able to try a new batch soon in 2017! Hopefully it'll go better...