Why is it harder to boil in my new pot?

[Summerland]

Hi all,

I have a big 20 gallon system with 30+ gallon pots without any insulation and I run a single 5500 watt BoilCoil element in my boil kettle. At the start of the boil I've got 28 gallons + and I have no problem getting a rolling boil going without a lid and about 85% power.

So recently I started doing 2.5 gallon batches BIAB style on my stove using my old 6 gallon pot and I really liked that I can brew inside while I'm watching the kid and still do things around the house, so I decided to build a small eBIAB setup that could work for either 2.5 or 5 gallon batches.

I got a Bru Gear 10 gallon pot, and brewed a 2.5 gallon batch on my stove using the new pot before all my equipment arrived. However, I could never get a boil! I've been doing this exact same amount on this exact same stove for several batches without a problem, the only thing that changed is the pot. Is the bigger pot (6 gallons to 10 gallons) really acting like so much of a heat sink that I can't get the water to boil?

I got my 1650 watt element and controller in, so I decided to test it and even with 4 gallons I could not get it to boil. I got 0.75 gallons of boiloff in an hour, but the water never visually boiled, it just steamed a lot. Is that good enough?

5500 watts for 28 gallons is 196 watts/gal, 1650 for 4 gallons is more than double at 412 watts/gal. Am I missing something here? Is it the fact the BoilCoil element goes all around the pot and this new element just has one foldback?

 

[Neens_]

Is the new pot wider than the old one?

 

[TexasWine]

What's an EZBoil element? Haven't heard of that one yet. EZBoil controller from Auber, I'm familiar with.

To answer your question, it could be your new kettle that's to blame. But for reference, I use 1650 watt elements and run one element at 100% power to boil about 7.5 gallons.

Edit: I mistyped. I meant to say one element at 100% power.

Another thing to keep in mind, you should be shooting for about 6-8% boil off, no matter what your boil vigor looks like. It's gonna be hard to do on your small batches, but try not to go over 10% maximum. I'd recommend putting your lid mostly on. It's about the only way you'll get there on a homebrew system.

 

[Wizard_of_Frobozz]

Boil rate isn't just a factor of heater power. The heat going in (from the heat source) must be greater than the heat going out in order to raise the temperature and ultimately bring about boiling. The conversion from liquid to vapor requires a LOT of heat.

If your pot has a lot of exposed surface area, then the heat you are putting into the liquid can escape quickly through that area. A 10 gallon pot with only 2.5 gallons in it means lots of metal that is open to the atmosphere - which allows the heat to leave. Stainless steel is a pretty good conductor of heat, so that open space on your kettle is "sucking" the heat out of your wort.

Your heater power may be enough to raise the temperature, but boiling requires a lot more heat, and the loss through the pot walls is probably to much. For water, it takes only 1 btu to raise 1 lb of water 1 degree F. To convert 1 lb of water to steam, it takes 873 btus!

 

[flars]

With the heat source inside the kettle you could insulate the outside to prevent some of the heat loss. Coupled with bringing the wort to a full boil with the lid fully on may save some time. Maintain the boil with the lid only partially off.

 

[Summerland]

What's an EZBoil element? Haven't heard of that one yet. EZBoil controller from Auber, I'm familiar with.

The answer is I’m an idiot and I meant Boilcoil from Blichmann.

 

[Summerland]

Thanks for all the answers, it’s something I didn’t really anticipate when I bought a 10 gallon pot. I thought I was being smart to plan for both 2.5 and 5 gallon batches, but now I need to get this figured out.

I was planning on adding a second element for 5 gallon batches, but I guess I may need it for 2.5 gallon batches too.

 

[JPBrewLI]

"I got my 1650 watt element and controller in, so I decided to test it and even with 4 gallons I could not get it to boil. I got 0.75 gallons of boiloff in an hour, but the water never visually boiled, it just steamed a lot. Is that good enough?"

Is that another submerged heating element? if so doesn't make any sense.
Not sure what kind of stove but if the bottom of the pot isn't completely flat it won't heat well.

 

[ODI3]

2 additional factors, aluminum pots boil faster, triclad pots boil slower on stovetop.
Also u can get canning elements to replace your electric stove element from ebay which are more reinforced and a bit stronger and sit a bit higher. I think they are 15$ each or so

 

[LarMoeCur]

You said it steel pot is a giant heat sink.

What was the old pot made of? Thermal conductivity of steel is 17 BTU/(hr·ft⋅°F). The Thermal conductivity of aluminum is 118 BTU/(hr·ft⋅°F). So, if you got a larger pot made of stainless steel you decrease the thermal conductivity by a huge amount over aluminum. If the old pot was aluminum. If the old pot was stainless steel you still increased the size (ft part of the equation) which has an affect on thermal conductivity.

It sure sounds like a voltage issue with the new 1650w element. I've seen videos of 10 gallons boil with a 1650w element. What controller are you using? I'd check the settings on the PID. What is the "t" cycle setting? It could be way low.

 

[Summerland]

Thanks guys.

The old pot was a 6 gallon Stainless pot with tri-clad bottom. My stove is a glass top, so being very flat is important, but I’m trying to get away from having to use the stove all together.

The new pot is a little wider, but only by about an inch. It is also a tri clad bottom, and it is much taller.

I am using the Inkbird PID and it heats up great until about 200 degrees. I get about 2.5 degrees s minute on 4 gallons, which I’m perfectly happy with, and I too have seen 10 gallons boil with a 1650 watt immersion element which is why I’m confused as to why this won’t.

I’ll have to try and go through the PID settings, as the instructions are terrible for this unit, but the rate at which it heats up makes me confused why I can’t get a decent boil.

 

[JDXX1971]

I am getting my 8 gallon pot back from Nor Cal Brewing Solutions today with a new tc port installed. I also plan to brew indoors with the Inkbird PID and either my 1200 or 1500 watt element. I sure hope I am able to get a boil going with one of the elements, I will test it out tonight and post back with my results.

 

[ancientmariner52]

Thanks guys.

The old pot was a 6 gallon Stainless pot with tri-clad bottom. My stove is a glass top, so being very flat is important, but I’m trying to get away from having to use the stove all together.

The new pot is a little wider, but only by about an inch. It is also a tri clad bottom, and it is much taller.

I am using the Inkbird PID and it heats up great until about 200 degrees. I get about 2.5 degrees s minute on 4 gallons, which I’m perfectly happy with, and I too have seen 10 gallons boil with a 1650 watt immersion element which is why I’m confused as to why this won’t.

I’ll have to try and go through the PID settings, as the instructions are terrible for this unit, but the rate at which it heats up makes me confused why I can’t get a decent boil.

Hi, Summerland. If it's not too difficult, you could wire your element, temporarily, direct to your power source. That is, pure manual control, 100% power. You'll quickly determine if you have a controller problem or not. Good luck!

 

[Summerland]

Hi, Summerland. If it's not too difficult, you could wire your element, temporarily, direct to your power source. That is, pure manual control, 100% power. You'll quickly determine if you have a controller problem or not. Good luck!

That is an excellent suggestion! It is already wired to plug right into a wall, so should be easy to run that test.

 

[augiedoggy]

Is the new pot wider than the old one?

I think we have a bingo!
This is a big factor.

There's a reason most of the prebuilt 120v systems out there use very narrow tall kettles... The wider the kettle the less efficient it is. this is why cheaper kettles are repurposed soup pots which are often about as wide as they are tall and the better kettles are taller and narrow.

also keep in mind the actual power output from an element has a tolerance that can very a lot... I have a 4500w ripple element I bought from spike that only puts out 4040w max and I own a couple "1000w" elements that only measure 800w so one person with a 1650w element could have 1650w of power and another could have 1505... Its the luck of the draw it seems not to mention your actual wall voltage comes into play when your really counting every watt... 230v will put out less power than 240v.

 

[jtratcliff]