dirty propane?

When I was doing my first brew in Croatia a couple of weeks back, the bottom of the kettle got really black. Like so:



It's much worse than it looks there, in fact. It's like if I were burning paper under the kettle, that kind of sooty black burned material. And it's not just blacking the kettle, it's like ashes on the kettle. An actual material there that's black rather than just a blackening. If you touch it, you get soot all over your hand.

After that first week, I figured, well, maybe the burner had some coating or paint on it that burned off and it wouldn't happen the second time. But brewed yesterday and again, there it was. It's actually a bit of a pain because I have to clean this in my shower. And it makes a helluva mess. The entire outside of the kettle is coated with this stuff and it doesn't come entirely off. Scrub the hell out of it, but there's a bit of black still all over the kettle. Guess there's nothing to be done about it.

So, what do you think? My guess is this is less than pure propane I'm getting, not as highly refined as I was getting in the States. From what I gather, there's a monopoly here with INA selling the only propane tanks. I'll see if that's true over time, but for the time being, they're my only option. I get a great boil and have no other problems. But that black soot is a helluva mess.

I think you need to adjust your air intake. You are burning too rich, you need more oxygen. The soot is a byproduct of unburnt fuel. The flames should be mostly blue with just orange tips.

You should be able to get the soot off with a green scrubby (not the metal kind), some cleaner like oxiclean (paste), and some elbow grease.

Beerrific said:

I think you need to adjust your air intake. You are burning too rich. The flames should be mostly blue with just orange tips.

You should be able to get the soot off with a green scrubby (not the metal kind), some cleaner like oxiclean (paste), and some elbow grease.

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Ah, okay. Make sense. Don't remember doing that in the past. Thanks for the heads up!

That happened to me. I didn't turn it up high enough. I had flames like you have. Soot was all over it. Then I learned that I need to turn it up way more to get the blue flames that will prevent the soot.

I'm not an expert on lp gas overseas by any means but the issues I know of that can cause sooting like you are talking about usually indicate improper oxygen to gas ratio, wet gas, or wrong gas pressure.

If it is wet (dirty) gas then there is not much you can do about that. More or less this means there is excess moisture in the mixture and causes an inefficient burn. I would guess that the problem may be with one of the other two though.

First try adjusting the air intake to the mixing chamber to try to get less of an orange flame and more of a blue one. Anytime that gas is burning orange instead of blue there are efficiency issues that will lead to more sooting and less heat than could be produced.

If your gas pressure is too low you can also get a lazy flame that will also burn inefficiently and cause sooting. One common cause of this is from spiders building nests in the orifice right before the mixing chamber/venturi tube. This may also be an issue with the regulator and could be solved with an adjustment if adjustable or replacing it if not.

Hope something here helps you.

I'll try air intake adjustment. Everything is totally new. Thanks!

LP can contain heavier molecules than propane, depending on the source. This is a common problem for RVers in South-eastern US. Adjust the air and making certain everything is clean.

By the way, the soot the doesn't come off will improve your heat transfer.

david_42 said:

LP can contain heavier molecules than propane, depending on the source. This is a common problem for RVers in South-eastern US. Adjust the air and making certain everything is clean.

By the way, the soot the doesn't come off will improve your heat transfer.

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For some reason, I heard Hank Hill's voice reading this post to me...

Flame is yellow, needs to be blue. Adjust whatever it takes to make it blue.

I haven't used that style of burner, but I believe the people who do give it about 4" of clearance from the burner to the bottom of the pot. It helps with the air/fuel mixing. Might be worth a shot.

It's actually a bit of a pain because I have to clean this in my shower. And it makes a helluva mess.

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In the future put liquid dish soap on the bottom of your brew kettle and your cleaning problems go away.

Here are some very old pics I took for demo purposes.
To make your cleaning easy

After brewing use a wet sponge and wipe clean.

Cheers,
ClaudiusB

Thanks. I'll see how it goes this upcoming weekend. Thanks for all the pointers, guys.

I had the same problem using an old tank. I probably had a cm of soot on the bottom of my boiler. I would assume that propane goes bad with age just like petrol.

As has been mentioned flame adjustment should take care of this, on a good note once you get the blue flame your boil time should reduce. A yellow flame is cooler than a blue flame.