[SpanishCastleAle]

I was listening to a Brew Strong episode on head retention and John Palmer (IIRC) mentioned; words to the effect, that the high heat load of some propane jet burners can reduce head retention.  I'm not completely clear on what he meant there but I took it to mean; "Don't boil the crap out of your wort."  I've heard some say to boil really hard and don't recall ever hearing anybody (prior to this) say; "Don't boil too hard."

Anybody agree/disagree with this?  Are there reasons to boil really hard or to ensure to NOT boil really hard (other than propane/energy usage)?

I don't have any real data but I have a couple of Pils-based beers that I boiled hard with a jet burner for 100 minutes.  I started with ~8 gal wort pre-boil to reach a final volume of ~5.5 gal.  The beers make foam but it drops very quickly.  I know Denny often says bad head is due to bad fermentations, and I won't rule that out, but these beers are pretty clean and I pitched a lot of yeast (cold), used yeast nutrient, aerated well, yada, yada.

This is using a relatively new brew stand with jet burners, perhaps I was puttin' the spurs to it just because I could.  FWIW, last weekend's batch of ESB that I boiled gently for only 50 minutes?  I couldn't read the hydro sample for an entire hour because the foam wouldn't subside (I'm not exaggerating, a full hour!).  But it was clear as a bell (as usual).

[Kit B]

This reply is pure speculation, but I wonder if it has to do with how much protein is being dropped out & turned into the break.
A thinner, less proteinaceous (sp?) beer will likely have less head retention...No?

[SpanishCastleAle]

This reply is pure speculation, but I wonder if it has to do with how much protein is being dropped out & turned into the break.
A thinner, less proteinaceous (sp?) beer will likely have less head retention...No?

Good speculation.  IIRC he did say something about it causing excessive hot break.

Regarding the thinner/less proteinaceous beer having less retention, I'm not so sure.  The classic head retention example frequently cited is Duvel...tons and tons of head that lasts.  It has lots of alcohol and a low FG and I assume it's made mostly with continental pils and lots of sugar; which I wouldn't expect to render a high protein beer.

[narvin]

This reply is pure speculation, but I wonder if it has to do with how much protein is being dropped out & turned into the break.
A thinner, less proteinaceous (sp?) beer will likely have less head retention...No?

Good speculation.  IIRC he did say something about it causing excessive hot break.

Regarding the thinner/less proteinaceous beer having less retention, I'm not so sure.  The classic head retention example frequently cited is Duvel...tons and tons of head that lasts.  It has lots of alcohol and a low FG and I assume it's made mostly with continental pils and lots of sugar; which I wouldn't expect to render a high protein beer.

It's also extremely highly carbonated... you can see the stream of CO2 bubbles in the glass for at least 10-15 minutes after pouring.  It's hard to tell if it's actually good head retention or just more foam that keeps being generated.

[SpanishCastleAle]

This reply is pure speculation, but I wonder if it has to do with how much protein is being dropped out & turned into the break.
A thinner, less proteinaceous (sp?) beer will likely have less head retention...No?

Good speculation.  IIRC he did say something about it causing excessive hot break.

Regarding the thinner/less proteinaceous beer having less retention, I'm not so sure.  The classic head retention example frequently cited is Duvel...tons and tons of head that lasts.  It has lots of alcohol and a low FG and I assume it's made mostly with continental pils and lots of sugar; which I wouldn't expect to render a high protein beer.

It's also extremely highly carbonated... you can see the stream of CO2 bubbles in the glass for at least 10-15 minutes after pouring.  It's hard to tell if it's actually good head retention or just more foam that keeps being generated.

True but many/most highly carbed beers do not have the head (nor the lacing) of Duvel.

[denny]

Being in the process of working my way through a case of Duvel, I can assure you that it's head retention, not just carbonation.

Interesting question, Matt.  Sounds like you've got the fermentation covered, so I doubt that's the issue.  I wonder if maybe the proteins get denatured (is that even possible?) if you boil too hard and that's what leads to reduced head retention?  Here's the article I often cite in fermentation related head retention issues.  It's got some general foam info and tests you can do to help yo diagnose where the problem might be.

http://byo.com/stories/article/indices/35-head-retention/697-getting-good-beer-foam-techniques

[narvin]

Being in the process of working my way through a case of Duvel, I can assure you that it's head retention, not just carbonation.

Denny, you're definitely right about the head retention the more I think about it.  Other highly carbonated belgians like strong dark and even gueze don't form much of a head despite their constant bubbling.  It seems like only the lightest of the high alcohol beers have great foam, though I don't know why.

It does seem like high carbonation prolongs already good head (insert joke).

[anthony]

How about some even more rampant speculation: maybe the step mash employed in making Duvel contributes to the head retention.

[nateo]

IIRC Noonan talked about different types of proteins in his book. "Albumins" are a class of water-soluble proteins he references. He describes the 120*-ish protein rest as an "albumin" rest, where the long proteins are broken into smaller, more soluble proteins. If they continue to be broken down, they'll turn into amino acids, but that takes 90+min.

So in a normal protein rest of 15-30min the big proteins should be broken down into albumins, which should contribute to body and head formation. The bigger proteins would clump and form hot break, while the smaller proteins stay in suspension.

I would agree with Anthony on this one, that (all other things being equal) the mash schedule has a big impact on head retention. With that said, I've had very good head retention on some single-infusion beers, some moderate-to-weak retention on some step-mashed brews, and some insanely/obnoxiously good retention on some step-mashed wheat beers.

[denny]

How about some even more rampant speculation: maybe the step mash employed in making Duvel contributes to the head retention.

I think that's very likely.