The Boil

[derek]

Hang on though. The no-chillers seal their boiling wort in a plastic container immediately following a 60 or 90 minute boil, sealing would hold in any DMS, and they leave it to sit around without chilling for a few days to cool by itself. They have no DMS problems doing that.

That, of course, was one of the examples I was thinking of. The other big one was something Jeff talked about in our BJCP training sessions: you can now make something very close to traditional Munich triple-decoctions, without the triple decoction, because of the highly modified malts available. That might have been possible in the 70s, but if it was, it was in its early stages. So much has changed since most of those books were written. Which is not to suggest that they're wrong: they're right, with the ingredients available at the time. Yeasts may have gone through even more changes than malt in that period, and yeast has to be a significant factor in the development of DMS (it is in most sulfur compounds).

[Jayme]

I think they two pages from a brewing text covers it well. It all depends on how much precursor you have in the malt. Lighter kilning leaves more precursor. Hard to say what modification does in that regard, but lets say it perhaps reduces precursor. It takes 40 min of boiling to use up half of the precursor. So if you have very little to start with, you'll have half that or less after an hour long boil. Then who cares how long the wort stays in the danger zone if there's very little left?

The other thing is cold fermentation temps produce dms. Dmso is also produced in the boil, and the yeast will strip off the oxygen molecule.


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[GuingesRock]

The only thing is, I don’t recall there being any limitations on the type of grain you can use for the no-chill method. Perhaps enough DMS is produced and got rid of within the 60 – 90 minutes.

An alternative explanation is that perhaps, this entire theory is “up the creek”, and DMS is caused by other factors that you mention. It’s almost tempting to say, to hell with all this theory, do a 30 minute boil and see what happens. I’d be reluctant to do it, because it might waste a day’s work, but that might mean that no one else has taken the risk either, since all the books advise against doing that, with convincing theory quoted again and again…but as far as I know, it is just theory.

...unless someone can present a convincing study on this?

[GuingesRock]

http://onlinelibrary.wiley.com/doi/10.1 ... 6845.x/pdf

http://onlinelibrary.wiley.com/doi/10.1 ... x/abstract

[GuingesRock]

Informative thread... one area I'm unclear on is the hot break

Is this the foamy crust that forms during the early boil?

Do we want to scoop this out or leave it in?

Hot break is produced all the while the boil is in progress, but the greatest bit is initially when it comes to a boil.

Recently I have begun to " scoop the foop "when it first forms as it reduces the cover initially and helps prevent boil overs. I have also heard it helps
keep down tannins in the wort as the foop contains a bit of chaff from the grain. It has been working out well for me these past few brews I have been using that procedure.

I skimmed my hot break for the first time today, after reading your post Tony. I tasted it and it really does have mouth puckering astringency.

Now the top of the boil is nice and clear….I wonder if the DMS can escape more easily now also?

[GuingesRock]

Informative thread... one area I'm unclear on is the hot break

Is this the foamy crust that forms during the early boil?

Do we want to scoop this out or leave it in?

Hot break is produced all the while the boil is in progress, but the greatest bit is initially when it comes to a boil.

Recently I have begun to " scoop the foop "when it first forms as it reduces the cover initially and helps prevent boil overs. I have also heard it helps
keep down tannins in the wort as the foop contains a bit of chaff from the grain. It has been working out well for me these past few brews I have been using that procedure.

Interesting thing, today I did a brew with about 25% of the hops in FWH. This is the first FWH brew I have done since I became a hot break skimmer, and all the FWH pellet hops were on the surface, mixed in with the hot break…I skimmed them off any way with the hot break, I didn’t really care as I probably have too many hops in this brew and I thought that I might still have oxidised flavour/aroma compounds in solution (the oxidised version is supposed to not be lost during the boil according to FWH theory).