"Boil to achive the hot break"

[EccentricDyslexic]

The late great Dave Line said that you only need to boil long enough to achive the hot break, and as i understand it, a more vigourus boil achieves the hot break quicker than a simmering boil due to the bashing together of the protein molecules. This made me think, if we introduce aditional turbulence ie by stiring or by whirlpooling, could we achive the hot break without boiling?

Another question- DMS boil off...some comercial brewers use lids on their boilers with small chimenys coming off, are we going over board keeping the lid off throughout the boil? when is dms actualy boiled off? nearer the start or nearer the end of the boil, or just gradualy throughout the boil?

Just me mind thinking stuff through again!

Steve

[Wolfy]

If you shorten your boil your hop utilization will most likely suffer quite a bit, in addition boiling (and boil duration) also has an impact on beer flavour due to Maillard reactions producing melanoidins and other compounds.

I was of the understanding that it's not actual DMS that you are boiling off but the precursors that go to make DMS later, and those precursors effectively have a half-life/minimum boil time in order for them to be reduced an appreciable amount, but that it's a continuous process throughout the boil.

I imagine that boiling wort is a fairly expensive exercise, so I'd have assumed if it was possible to achieve similar results with mechanical agitation and not actually needing to boil then it would be a fairly common practice in industry.

I have my boiler turned up high until I get to the hot break stage, once there I turn it down as far as I can to maintain a 'rolling boil', just hot enough to ensure that the kettle contents are turned over (from bottom to top) to allow for adequate mixing and release of unwanted volatile compounds.

[Wolfy]

the increase in hop utilisation drops off with an increase in time and the utilisation/time graph really flattens out at 60 mins, a disproportionate amount of time is required to achieve any further real increase in utilisation.

Where as with a 1040 gravity wort 0-60 mins will return a utilsation figure of 25% it takes a further 30 mins to achieve another 2.5%

Of course, but when the OP says "that you only need to boil long enough to achive the hot break" I assumed he was suggesting a boil of no longer than 10-15mins, in which case hop utilization would most likely be less than half the 60min figures.

[Aleman]

the increase in hop utilisation drops off with an increase in time and the utilisation/time graph really flattens out at 60 mins, a disproportionate amount of time is required to achieve any further real increase in utilisation.

Where as with a 1040 gravity wort 0-60 mins will return a utilsation figure of 25% it takes a further 30 mins to achieve another 2.5%

Of course, but when the OP says "that you only need to boil long enough to achive the hot break" I assumed he was suggesting a boil of no longer than 10-15mins, in which case hop utilization would most likely be less than half the 60min figures.

The hot break takes a lot longer to achieve than 10-15 minutes . . . . Unless of course you have been reading Palmer who seems to think that the foamy scum on the top of the wort as it "Coppers up" is the hot break . . . . (Technically parts of it are) . . . but the 'hot break' event takes place much later in the boil . . and it describes the point at which the vast majority of medium and long chain polypeptides coagulate together to form loose fluffy clumps which can quite clearly be seen moving in the wort as it boils, and the wort visibly brightens. . . . it is assisted with the use of carrageenan finings . . . this is best achieved with a boil length of 90 minutes.

[Blackjack]

I do not know of anywhere in commercial practice where the copper is completely uncovered and some even seal the boiling copper to pressure cook, not that anyone wants to necessarily follow commercial practice.

DMS and it's precursors are at a low level in pale malt and are readily driven off during the boil, so all we have to do is let some vapour escape, as brewers have been doing for ages with a small prop under a corner of the lid. If anyone only does it one way try it the other way and you will be amazed at the excess use of power with the lid off. A bit like trying to boil a pan of water on a campfire in a breeze.

I recently brewed a golden bitter with lager malt which contains more DMS precursors and then racked it off out of the FV after only 3 days, ( I was in a rush). It had a very slight DMS green veggy note. DMS can also dissipate from the FV while conditioning, I understand.