[Robert]

The magic is still in heating the kettle asymmetrically!

And this is to get wort movement with a lower boil intensity?

Exactly.  Some big commercial kettles use either asymmetrical heat or mechanical agitation to the same end.  It's simple for me since I have a 10 gal kettle sitting across two burners on the stovetop.   I use both to get the heat up, then turn one way down and the other nearer high heat during the boil.  I think Martin has some ideas how to do this on a propane burner.

[Frankenbrew]

The magic is still in heating the kettle asymmetrically!

And this is to get wort movement with a lower boil intensity?

Exactly.  Some big commercial kettles use either asymmetrical heat or mechanical agitation to the same end.  It's simple for me since I have a 10 gal kettle sitting across two burners on the stovetop.   I use both to get the heat up, then turn one way down and the other nearer high heat during the boil.  I think Martin has some ideas how to do this on a propane burner.

So I've got my kettle offset to one side by a couple of inches. I've already done this, so I know it creates a rolling, circulating boil. So, when it comes time to vent and volatilize the unwanted flavor compounds, am I offsetting my lid on the same side as the burner or the opposite side?

[Robert]

So I've got my kettle offset to one side by a couple of inches. I've already done this, so I know it creates a rolling, circulating boil. So, when it comes time to vent and volatilize the unwanted flavor compounds, am I offsetting my lid on the same side as the burner or the opposite side?

Hmm.  Never thought about that.  I keep mine very slightly ajar the whole time, and it's pushed to one side, which puts the crescent opening centered on 3 o'clock and the burner at 12.  This is purely a matter of convenience and habit, no science involved whatsoever.  Anybody think it makes a difference?

[Slowbrew]

My thought is steam rises from the whole surface and then seeks the easiest exit point.  In other words it shouldn't matter.  But that just my SWAG.

Paul

[mabrungard]

My thought is steam rises from the whole surface and then seeks the easiest exit point.  In other words it shouldn't matter.  But that just my SWAG.

Paul

If there is enough exchange with the atmosphere, then the kettle can be partially covered. If its too steamy back under your lid, then it might be a good idea to open the lid a bit more. But the real litmus test is if you and your drinkers find your beer has notable DMS in the flavor or aroma.

[Robert]

In the last CB&B Josh Weikert has a "busting homebrew myths" type article.  Without any real explication,  he does at least advise people to stop wasting time,  and effort and fuel, boiling their wort so darn much.  Just as long as their longest hop addition, as long as that's at least 15 minutes, he suggests.  The word is getting out, but does need more context and refinement.  Which should come with Martin's Zymurgy article.

[weazletoe]

Technically, you're probably better off with a low boil than a high one.  Practically, I don't think it makes a lot of difference.

But what does your pragmatic side say?

[riceral]

While researching that presentation on Wort Boiling, I came across an Institute of Brewing and Distilling journal article that stated that they produced beer via a boil with only 2% evaporation loss. They said it tasted fine. Since they didn't identify what malts they used, I'm less confident that brewers can actually get by with that little evaporation. Most pro's that produce good products apparently evaporate about 4% to 8%.

I'm trying to limit my loss to about 8% and I do brew some beers with high pils malt content. The main thing that brewers need to concentrate on is the circulation of wort within their kettle. You actually don't want the kettle centered on your burner. Having the burner offset slightly to one side of the kettle will help promote a better rolling action for the wort.

A volcanic boil is not necessary. If there is ANY evidence that the wort is boiling, its as hot as its going to get and all the chemical reactions that we rely on will occur at the same rate. But you probably do need some heat input in order to produce the rolling action.

Hey Martin,

I saw your presentation in Portland and enjoyed it. I was planning on listening again more closely when the presentations were released. Well, we know that there were problems with the recording and I, along with everyone else, can't see your presentation.

Any chance you might be willing to repeat it in Providence? Maybe the powers that be can get the recording right this time. 😁

[BrewBama]

While researching that presentation on Wort Boiling, I came across an Institute of Brewing and Distilling journal article that stated that they produced beer via a boil with only 2% evaporation loss. They said it tasted fine. Since they didn't identify what malts they used, I'm less confident that brewers can actually get by with that little evaporation. Most pro's that produce good products apparently evaporate about 4% to 8%.

I'm trying to limit my loss to about 8% and I do brew some beers with high pils malt content. The main thing that brewers need to concentrate on is the circulation of wort within their kettle. You actually don't want the kettle centered on your burner. Having the burner offset slightly to one side of the kettle will help promote a better rolling action for the wort.

A volcanic boil is not necessary. If there is ANY evidence that the wort is boiling, its as hot as its going to get and all the chemical reactions that we rely on will occur at the same rate. But you probably do need some heat input in order to produce the rolling action.

Hey Martin,

I saw your presentation in Portland and enjoyed it. I was planning on listening again more closely when the presentations were released. Well, we know that there were problems with the recording and I, along with everyone else, can't see your presentation.

Any chance you might be willing to repeat it in Providence? Maybe the powers that be can get the recording right this time.

I second the motion.


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