Heating Element Scorching - Long boils w/ High OG Wort

[Nick Poggetti]

I've been having some troubles brewing my big beers lately ever since I moved away from the Blichmann Boilcoil. I am using the Brewbuilt Slingblade 22 gal from Morebeer, and was also using the Brewhardware ripple element. All 240v, 5500/5000 watts. Brewcommander for the control panel.

The Blichmann Boilcoil - what I can assume - had so much surface area, it was truly ultra low wattage density. Which is why I never had the issues in the past. Unfortunately, I upgraded my kettle to all triclamp (Spike Tank) and in that process had to change the heating element because I didn't want to drill 2 - 7/8" holes in the new kettle for the BoilCoil. Now.... I'm kind of leaning to going back that route unless I can figure out how to avoid this.

Here's what I've gone through to troubleshoot. Mind you, this only happens on high OG (1.1+) and long boils (3hr +), open top boil to help speed boil off. No issues with lower OG, >60 minute, steam condenser on (30% element power).

• Was told scorching could be happening during the mash while recirculating, lower the re-circulation speed over the top to limit potential air pockets around the element. I'm fairly certain I'm good here as I've got the power setting on extremely low during the mash, and recirculating to 1-2L/minute.
• Lower the power % to the heating element as much as possible. I kept it at 50% to barely a simmer, which resulted in a longer boil to reach my desired OG. I took my time bringing it to a boil, never putting it past 80%.
• Changed from the 5500 watt Ripple element to the 5000 watt Slingblade for slightly more surface area/wattage disbursement. I'm certain this helped a little, but still got a final product that tastes like a cigarette. No smoke aroma though which was an improvement from the ripple element.
• Cut the heat and recirculate every so often during the boil to try and mix up the wort.
• Changed the "Cycle Time" setting in my Brewcommander from 5 seconds to 1 second. This setting determines how frequently the power is cycled on and off when temp is within the control band.
• When I added the DME at the end, heat was off, it was slowly added and stirred vigorously. Could this be a source of the scorch? When cleaning the element, the carbon material was almost like a shell on the element. Think a chocolate shell on ice cream that cracks off easily.

The following is what I'm planning on trying to remedy this before going back to the Boilcoil and modifying the kettle with non triclamp penetrations.

• Cut in half my batch size in hopes to improve my efficiency so I don't need to boil so long to achieve my desired OG - previously was doing 15 gallon batches into the fermenter. Now plan to do 2- 7-8ish gallon batches with the Steam Condenser on to reduce the element power even more. Previously I was pushing my capacity to the limit, with efficiency close to 50-55%.

Anyone have any thoughts? Am I going in the right direction?

My hunch... very long boil time with very concentrated amounts of sugar is the source. But hoping to see if anyone has any input.

Thanks in advance for any thoughts.

 

[Broken Crow]

Cut the heat and recirculate every so often during the boil to try and mix up the wort.

This part has me wondering; Are you not constantly running reciculation? As long as there's no air in your lines, there won't be any 'air pockets around the elements', but if the wort is not moving over the element while it's powered up it is very likely to burn. Maybe I'm misunderstanding something.

 

[Nick Poggetti]

I am not constantly running the pump during the boil. It's my understanding that at boiling temps, there will be cavitations which is not ideal for the pump itself. I'm not sure I've heard of anyone recirulating constantly while boiling?

During the mash; yes... recirculating the entire time. The air pockets I mention can come during the mash if wort is being recirculated on top too fast and is not draining back down through the grain bed to reach back down to the bottom.

For reference, if it helps. I'm using a single vessel eBIAB type of system. Forgot to mention that.

It's per Bobby w/ Brewhardware's design. Recirculating both over the top and back in through the whirlpool at the same time.

 

[Broken Crow]

I might be biased because I'm disabled and standing and stirring is too much for me, but when I looked at the physics of it, using a 5500W Camco element myself, it seemed pretty clear to me that the temperature ramps would definitely burn it if it wasn't moving so I've always run constant recirculation...As to the air pockets, I've only encountered them when first priming the pump, so I'd pull my camlock off the pump input to bleed the lines (now I use a Riptide with the bleeder valve) and apart from priming, it's just hot wort running through. I do also have brain-damage though, so I might be missing something obvious to a healthy brain.

 

[Nick Poggetti]

Fair enough, thanks for the input. I'm only echoing what I've read or been told regards recirculating during boiling. I'm really not that smart when it comes to the science of water flow and physics

 

[Bobby_M]

I would not run a pump that is drawing from a boiling kettle. In general, I shut my pump off at 180-190F max on the run up to a boil. Sure, when you first start whirlpooling it will be hotter, but you're still not adding active heat.

I'll be the first to admit that I don't make beers with an OG higher than 1.100 so I have no personal experience with this but this is the first time I've heard of the problem on a regular basis.

I'm quite sure the cycle time reduction to 1 second was in the correct direction. Even at 50% power, a 6 second cycle time means 3 full seconds at 100% output.

Question: Have all of the scorching episodes included a malt extract addition?

 

[doug293cz]

I'm quite sure the cycle time reduction to 1 second was in the correct direction. Even at 50% power, a 6 second cycle time means 3 full seconds at 100% output.

I agree, this can be a big deal. With a Pulse Width Modulation (PWM) cycle time of 1 second, you still have full power for 0.5 seconds at 50% power. This is a area where the Auber EZBoils can offer an improvement. They do something different than PWM, which I like to call Pulse Count Modulation. At 50% power, and lower, the maximum "ON" time (i.e. full power time) is limited to 0.0167 seconds. So, these controllers are the least likely to lead to scorching issues.

Additionally, between 50% power and 67% power, the maximum full power time is 0.0333 seconds, and between 67% power and 75% power, the maximum on time is 0.0500 seconds.

Brew on

 

[Nick Poggetti]

Question: Have all of the scorching episodes included a malt extract addition.

Yes. Looking back, they have all had DME additions. We cut the heat and stirred as much as possible to keep clumps from forming. Would transferring to a separate vessel to mix in, then adding back in be worth looking into?

 

[Nick Poggetti]

I agree, this can be a big deal. With a Pulse Width Modulation (PWM) cycle time of 1 second, you still have full power for 0.5 seconds at 50% power. This is a area where the Auber EZBoils can offer an improvement. They do something different than PWM, which I like to call Pulse Count Modulation. At 50% power, and lower, the maximum "ON" time (i.e. full power time) is limited to 0.0167 seconds. So, these controllers are the least likely to lead to scorching issues.

Additionally, between 50% power and 67% power, the maximum full power time is 0.0333 seconds, and between 57% power and 75% power, the maximum on time is 0.0500 seconds.

Brew on

Thank you for the response. While reading through these numbers I don‘t fully understand the math but I understand the Basic concept.

The idea of changing out to an auber EZBoil… while not ideal… just based on cost, offers an idea down the road if I can’t fix it otherwise.

 

[day_trippr]

Would transferring to a separate vessel to mix in, then adding back in be worth looking into?

That shouldn't be necessary. I have many recipes that call for very late sugar additions to the kettle and I just shut off the heat until I have thoroughly stirred said additions in. One calls for four pounds of honey - which would be ripe for a righteous scorching - but I just add a touch of extra diligence for that

Cheers!

 

[Nick Poggetti]

That shouldn't be necessary. I have many recipes that call for very late sugar additions to the kettle and I just shut off the heat until I have thoroughly stirred said additions in. One calls for four pounds of honey - which would be ripe for a righteous scorching - but I just add a touch of extra diligence for that

Cheers!

Thanks. I've had tons as well. Though, my big OG beers are propped up a little more with DME than a typical gravity correction type of thing.

 

[Broken Crow]

I would not run a pump that is drawing from a boiling kettle. In general, I shut my pump off at 180-190F max on the run up to a boil. Sure, when you first start whirlpooling it will be hotter, but you're still not adding active heat.

I'll be the first to admit that I don't make beers with an OG higher than 1.100 so I have no personal experience with this but this is the first time I've head of the problem on a regular basis.

I'm quite sure the cycle time reduction to 1 second was in the correct direction. Even at 50% power, a 6 second cycle time means 3 full seconds at 100% output.

Question: Have all of the scorching episodes included a malt extract addition?

I agree, this can be a big deal. With a Pulse Width Modulation (PWM) cycle time of 1 second, you still have full power for 0.5 seconds at 50% power. This is a area where the Auber EZBoils can offer an improvement. They do something different than PWM, which I like to call Pulse Count Modulation. At 50% power, and lower, the maximum "ON" time (i.e. full power time) is limited to 0.0167 seconds. So, these controllers are the least likely to lead to scorching issues.

Additionally, between 50% power and 67% power, the maximum full power time is 0.0333 seconds, and between 57% power and 75% power, the maximum on time is 0.0500 seconds.

Brew on

Thanks to both of you! Something I need to ask: Is there anything detrimental to running constant recirculation? I've had an MP-15RM pump running it, but I bought a Riptide for the 3V rig I am slowly building and I've only used it in the test runs/batch, but it had quite a vigorous recirc so I throttled it down a bit before I connected my CFC. Because of my disability, I've tried to build in as much labour-saving as I could, and standing and stirring is hell so I chose to run the pump for the whole brew...is there a downside to that?

 

[sibelman]

scorching could be happening during the mash

You might want to look harder at this, Nick. I've rarely made beers over 1.100 OG, but often in the 90s. I've never seen any scorching on my element.

Thoroughly stirring in DME with power off should eliminate that as a concern.

I don't mash in a vessel with an element, so I wonder: is your malt in physical contact with your element?

 

[Clint Yeastwood]

I fully realize this is probably a stupid question, but are you actually seeing scorched stuff every time? I mean, you're sure the burned crud is gone before every brew?

For what it's worth, my Braumeister will not let me run the pump at high temperatures. It will shut off at a certain temperature when I try to heat and pump manually. Hard to believe Germans would try to tell someone what to do. Shocking.

In my experience as a cook, I have found that starch burns very easily but sugar does not. Makes me think your problems are mostly taking place before you have conversion, and I would GUESS that DME, which is mostly sugar, would be slow to burn. Maybe someone here knows more. I have never actually tried to subject DME to a lot of heat. Web says DME is only around 17% starch.

It sure sounds like your problem is either air or slow movement of wort, which lets the wort sit on the burner surface too long.

Drilling stainless is no fun, but a small carbide bit followed by a unibit should make it easier. A spring-loaded punch can dimple the metal to prevent the carbide from wandering.

 

[Nick Poggetti]

I don't mash in a vessel with an element, so I wonder: is your malt in physical contact with your element?

For sure. Would be a good idea to drain the vessel after the mash and check.

No - I have the heating element underneath the BIAB false bottom that Bobby sells:

https://www.brewhardware.com/product_p/biabbottom17.htm
And the grain is in a bag.

 

[Clint Yeastwood]

I would think that heating element would be hard to sell if it were too hot to use. Everyone would return it.

 

[Nick Poggetti]

I fully realize this is probably a stupid question, but are you actually seeing scorched stuff every time? I mean, you're sure the burned crud is gone before every brew?

No stupid questions, I appreciate the input and making sure nothing is missed.

Yes - I fully break it down to remove the hard black crusty shell when it happens. My latest batch was better than previous as I've been taking steps to try and prevent it which certainly is helping.

Thank you for the comments about your experience as a cook, something interesting to learn. I will take steps to triple check it's not happening during the mash... as you say, air or slow wort movement.

Also, I've got no issues drilling stainless if I end up going that route. Though hope to fix the process rather than buy more equipment!

 

[Clint Yeastwood]

I have had starch burn onto a pot many, many times, but it never happens with sugar unless I want it to. Also, sugar dissolves very easily, but starch will stick to a pot and force you to use something like citric acid or vinegar to remove it. I suppose starch is less soluble. Maybe that's why our bodies turn it into sugar.

 

[doug293cz]

Thank you for the response. While reading through these numbers I don‘t fully understand the math but I understand the Basic concept.

To understand the math, you need to understand how the two different power modulation modes work, which is a fairly long explanation. I didn't want to sidetrack the thread too much with something that is a bit off-topic. I can write up an explanation if anyone is interested.

Brew on

 

[Agent]

I'm going to agree with @Clint Yeastwood that there is probably a starch-related issue that starts during the mash and manifests during the boil.

I use a standard 5500w element in my keggle, and one of the worst scuzz came from a non-enzymatic mash (cold soaked grain and ran the wort straight from 70F to boiling). It coated the whole bottom of the keggle nearly 1/8" thick. I don't heat/recirc my mashes, and boiling 1.110 beers hasn't caused an issue by itself.

A fellow club member had a system that direct fired an element in the mashtun and had similar troubles with many of his beers (most at 1.090+).

Are your 3 hour boils for flavor or just to hit volumes? Because it sounds like it's for volume, and I certainly drop my batch size after a certain desired gravity. My keggle will do 10 gallon batches to 1.080 from malts while holding 75% efficiency, but starts to fall on its face after that.

 

[BarryBrews]

Lower the power % to the heating element as much as possible. I kept it at 50% to barely a simmer, which resulted in a longer boil to reach my desired OG. I took my time bringing it to a boil, never putting it past 80%.

This is a little different but might help you anyway. There's been a lot FUD about scorching your wort with a RIMS system. I avoided this potential by using a SCR to control the input voltage to my PID, which can only act as a PWM in regards to power to the heating element. In other words the SCR controls the power and the PID the temperature. Works great. Only heating full power when desired. Also use a SCR on my boiling kettle where the PID controls are unneeded. Gives great control over the vigorousness of the boil,

 

[Nick Poggetti]

Thanks all. I've decided I'll give it another go like this:

1- Batch size cut down by 40%
2- Two concurrent mashes in old cooler mash tuns.
3- Boil in the kettle as normal.

At least this way, I'll learn if I am in fact having the scorching issues come during the mash or during the boil. Reconsidering some of the input above, a likely guess is that due to the amount of grain (about 50lbs) in the 20 gallon kettle, with a decently thick mash, could very well be causing the issue. I know I mentioned thinking this wasn't the case, but it makes sense because otherwise we'd hear a lot more of scorching if people were having more issues by boiling. I think?

If i end up having the problem again, then I can troubleshoot the boil from there...

 

[Bobby_M]

The idea of inspecting the element between the mash and boil phase is a pain in the ass but at least it rules out the possibility that the scortched coating isn't kicked off during the mash. Despite a lot of warnings, I've had customers tell me the recirc is set really slow like 1 quart per minute but they still scorched. After begging for a video of the recirculation rate they typically use, it is often obvious that the rate was never measured and committed to memory and the recirc rate was definitely well over a GPM. Not accusing you, just illustrating a misunderstanding and disregard for the importance of being careful in may previous cases.

If the element is shiny clean after the mash, I would move on the added DME. There would be no harm at all in draining off a gallon and diluting the DME into that before pouring it back in. It could be a matter of starting with a pretty high SG in the kettle to begin with so it would take a bit more effort to dissolve new sugar.

 

[hottpeper13]

I use the 3500 watt induction burner and have noticed that a full volume BIAB wort leaves a 6" ring on the kettle bottom that looks like starch build up,it's quite thick sometimes. When I use the mash tun with vorlouf that spot is minimal and can still see thru it.
I think your solution will greatly improve it or eliminate it.

 

[Nick Poggetti]

The idea of inspecting the element between the mash and boil phase is a pain in the ass but at least it rules out the possibility that the scortched coating isn't kicked off during the mash. Despite a lot of warnings, I've had customers tell me the recirc is set really slow like 1 quart per minute but they still scorched. After begging for a video of the recirculation rate they typically use, it is often obvious that the rate was never measured and committed to memory and the recirc rate was definitely well over a GPM. Not accusing you, just illustrating a misunderstanding and disregard for the importance of being careful in may previous cases.

If the element is shiny clean after the mash, I would move on the added DME. There would be no harm at all in draining off a gallon and diluting the DME into that before pouring it back in. It could be a matter of starting with a pretty high SG in the kettle to begin with so it would take a bit more effort to dissolve new sugar.

Yep - hear you loud and clear. I know it's the first thing you mentioned when I emailed you a while ago. I did think I got past it, but we'll see for sure.

 

[Nick Poggetti]

So just an update. Took lots or all of the above in to consideration and did another all day brew yesterday. Decided to do 3 seperate mashes in coolers and just use the 20 gal kettle as a boil kettle. Long boil to reach my desired gravity, added supplemental DME to also reach that gravity in a seperate kettle that I drew a few gallons off to mix in. Ran power at 30% for the duration of the boil with the steam condensor on...no scorching!

Long story short, most likely scenario was it's happening in the mash due to previously cramming the kettle chalk full to the capacity even with rice hulls and a bag with a larger micron size. Then the boil was exacerbating it. Small chance it was DME addition as well but looks like i have my strategy for big beers now.

Thanks folks.