Kettle Souring with Direct Fire

[MikeS]

Hello All-

I'm looking into making a kettle-soured beer in the near future. I have a 10bbl direct fired brewhouse. Most of the folks I've talked to who have done this have steam jacketed kettles. Has anyone done a kettle soured beer in a direct fired kettle? I have the capacity to set the temp when the burner fires and an effective whirlpool circuit, but I'm a bit concerned with the heat being a bit "uneven" or potential scalding or unacceptable temperature swings.

I'm probably overthinking this, but though I'd throw it out to the collective. Does anyone have any experience or thoughts or advice on this?

Thanks and Cheers- Mike

[beermkr]

I am planning to do the same thing. My intention was to turn my burner control way down and set the temp control. That way it is a gental heat that should be more even and not scorching in the fire box.

[tjc27]

I think you will find at 10bbl it will hold the temp fine in most cases without heat.

[FourSonsBrewing]

You'll be fine, I did a kettle sour on my 10bbl direct fire. After 3 days the temp had only dropped about 10 degrees.

[MikeS]

Awesome. That's kind of what I figured but the confirmations are greatly appreciated and make me much more confident jumping into this.

Thanks guys!

Cheers- Mike

[StonesThrow]

I did this just a couple weeks ago with our 3BBL. After wort was done, just capped off the kettle and left it alone. Temp dropped about 20F in 2 days. Soured nicely.

[Junkyard]

I started at 115 degrees with my 1.5 bbl kettle and the temp held great for a couple days, the beer soured very nicely. I would say you'll be fine without extra heat but if you really need the peace of mind I would just put a couple little electric heaters under your kettle and that should help even more

[604M]

How is everyone blocking/capping their steam vents to prevent oxygen from getting in after purging with C02 or any foreign falling in from outside air?

[Junkyard]

Take it apart and cover it with tin foil

[rudge75]

How is everyone blocking/capping their steam vents to prevent oxygen from getting in after purging with C02 or any foreign falling in from outside air?

I just made an airlock with a hose from my kettle stack into a bucket of paracetic, just like a regular fermentation. That way I could check this hose while I was purging the kettle with co2.

[604M]

Take it apart and cover it with tin foil

I'm pretty sure I can't take mine apart. I tried briefly, but its one solid piece. Anyone else have this type of stack and are able to kettle sour?

[Rooh]

I have used my direct fire kettle to sour wort at 118. I would let the burner come on, I don't think there was a problem from this. I got on my roof and taped a garbage bag over the top of my steam vent.

[MikeS]

As far a sealing the stack, I'm in the same boat as Mr. 604M. And getting up on the roof isn't really doable with the two feet of snow up there right now....

I was thinking of using some sort of expansion plug like this:

<http://www.mcmaster.com/#expansion-test-plugs/=w710hv>

I have to double check, but I think the inside diameter of the drip ring is just about 6 inches. I was also thinking that maybe even a balloon or an inflatable rubber bouncy ball would work, I'm just a bit concerned that any substantial downdraft might dislodge it into the wort.

Thanks again for all the replies, gents.

Cheers- Mike

[d_striker]

Inoculate at 115 and seal it up. Don't whirlpool. Your insulated kettle should maintain temp in lacto's preferred temperature range for at least 2-3 days depending on ambient temp.