Steam condenser boilover and figuring out proper power percentage

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birzzz

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HI,

I am using a condenser that is normally used on a still and I have some questions.

Kettle is a SS Brewtech 20 gallons, electric element is 5500W. Since using this setup I have done 2 batches and my boil off rate seems pretty low. I also experienced several boilover especially after adding hops during the boil. Last batch I eneded up setting up to 33% power output, but over the course of 60 minutes boiling, only 3/4 of a gallon has been evaporated. If I bump more than 33% power end up with boilover. Is it normal? should I just adjust my boil off rate in brewfather to account for that? Is 33% within the norm?

Here is my setup, you can see my condenser in the red circle:

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Thank you in advance,
 

doug293cz

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Nothing wrong with 3/4 gallon boil-off. 33% power (~1815W) seems reasonable - people boil 5 gal batches with ~1650W.

Boiling harder provides no real benefits. Hop oil isomerization and DMS elimination depend on time at boiling temp, not how hard you boil. Reduced pre-boil volume (due to less boil-off) will reduce lauter efficiency by a small amount, but this shouldn't be a big issue.

Brew on :mug:
 
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RedRyderr

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FWIW - I'm doing 5 gallon batches in a 15 gal kettle with a DIY steam condenser (6 or 6.5 gals wort with 5500 watt element). I'd have to keep the power output pretty low like that to prevent boil overs too (30%-ish). With a few drops of Fermcap and a 9 GPH nozzle in the condenser I can turn the power up if I want, and I feel that I get a pretty good boil off rate. Still not as much boil off as an open kettle though.
 

k-os

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I use the SteamSlayer from BrewHardware on my 15 gallon kettle with 5500W element and boil at 28% power with around 0.75 gallons boiled off in an hour. I think you're fine. Just adjust your boil-off rate in Brewfather to account for it.
 
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birzzz

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The tube in tube style condenser is likely not efficient enough for this task. The purpose-built condensers for steam condensing put the coolant water spray in direct contact with the incoming steam.
I am curious about what do you mean by "not efficient enough" exactly? During my first 2 batches with this setup, the liquid exiting the condenser was really cold and I saw almost no vapour exiting the lid. When distilling, the condenser is specifically designed for that purpose, changing vapour to liquid.

Thanks,
 
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Bobby_M

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I am curious about what do you mean by "not efficient enough" exactly? During my first 2 batches with this setup, the liquid exiting the condenser was really cold and I saw almost no vapour exiting the lid. When distilling, the condenser is specifically designed for that purpose, changing vapour to liquid.

Thanks,
If the liquid is coming out cold then I'm wrong.
 
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birzzz

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If the liquid is coming out cold then I'm wrong.

it is indeed coming out cold, but I am just unsure about the right boiloff rate and percentage of power I should apply. I have done several other tests with water yesterday:

Again element is rated at 5500W, boil kettle is 20 gallons and tests were done with 15 gallons of water to start.

power applied / liter per hour
33% / 1.14
40% / 1.62
42% / 1.71
44% / 1.80
48% / 2.10
50% / 2.34
100% / 5.40

What do you think would be the optimal configurations based on those results? I will add anti-foam from now on to avoid boilover as well.

Thanks,
 

Gozie Boy

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I've got a Spike 20 gal BK and 5500W element with a homemade (Brundog) 2" condenser mounted to the side with 9gph nozzle. I last measured 0.9 gal./hr BO with 50% power. That is more than birazz quotes, but using a different condenser design.

[BTW, as long as I keep the initial boil volume to less than 16 gal in the BK (I'm usually around 15 gal.), once I get past the initial boil break period, and using a few drops of FermCap, I never experience boil over events.]
 
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it is indeed coming out cold, but I am just unsure about the right boiloff rate and percentage of power I should apply. I have done several other tests with water yesterday:

Again element is rated at 5500W, boil kettle is 20 gallons and tests were done with 15 gallons of water to start.

power applied / liter per hour
33% / 1.14
40% / 1.62
42% / 1.71
44% / 1.80
48% / 2.10
50% / 2.34
100% / 5.40

What do you think would be the optimal configurations based on those results? I will add anti-foam from now on to avoid boilover as well.

Thanks,
The goal isn't to boil off lots of liquid... commercial breweries don't. The goal (noted by @doug293cz above, is to isomerize and burn off volatiles. So put in whatever power is needed to maintain a gentle simmer. It's hard to see it with the lid on, but once you figure it out, it isn't going to change much. Power rates tend to get cut in half-ish when closing the lid and adding a condenser.

BTW, I like the still condenser idea... but where is the heat going? I know its out that red pipe (assuming counterflow), but where that goes?
 
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birzzz

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The goal isn't to boil off lots of liquid... commercial breweries don't. The goal (noted by @doug293cz above, is to isomerize and burn off volatiles. So put in whatever power is needed to maintain a gentle simmer. It's hard to see it with the lid on, but once you figure it out, it isn't going to change much. Power rates tend to get cut in half-ish when closing the lid and adding a condenser.

BTW, I like the still condenser idea... but where is the heat going? I know its out that red pipe (assuming counterflow), but where that goes?
It goes down the drain, but the flow is minimal.
 

ParabolicDestination

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Seems inline. I have a 24 gallon BK and have around .5-.75 gph boil off with 5500w element @ 31-32%. I set the high alarm to 209f and set temp to 212 on auto mode. Then click over to manual mode when alarm kicks on. I set to 32% and starts to low vigor boil. Takes a bit of fine tuning depending on your elevation/element power but you’ll find that happy medium between boil/no boil. Keep dropping percentage of on-time while test boiling until the boil stops per temp shown on the PID then just go up a percentage or 2 to keep the PID flickering between boil and no boil. My boil temp @ ~846 feet is 210.5 if that helps with your percentage calc.
 
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