Boil length

[Indian_villager]

As with everything else, it depends. I can't find the article now but I remember one where it showed the decay rate of the DMS precursor in wort relative to energy input. So if you are pumping in more heat and have a higher boil off rate or more specifically vapor flux out of the top surface (so kettle diameter does play some part), you have a far more significant reduction in the DMS precursor. The results weren't as obvious as if you increase your boil rate from 1gph to 2gph you can get done in half the time. It was only a minor increase that led to a much faster decay.

I will usually boil for 60 mins, but I have boiled for 30 or 45 without worry even on beers heavy in pilsner malt. I'm running an electric setup with a 5.5kw element in a 10gal kettle. During my boil I'm usually at 32% output on my EZBoil.

For my shorter boils I make up the IBUs with weight of hops and call it good.

 

[HM-2]

I do modern 30 minute boils for almost every style I produce, with the exceptions of Bocks and other malty lagers, and things like barleywines.

 

[mabrungard]

I wrote an article on wort boiling in the May/June 2019 issue of Zymurgy that covers this subject.

The bottom line is that hop bittering utilization is pretty well maximized at about the 60 minute mark and its generally a good economic decision to end there...if your goal is imparting adequate bittering with the least time, power consumption, and hop consumption.

Another factor for selecting your boiling duration is the fact that boiling does damage wort and create aged beer effect. In the case of an Old Ale or Barleywine, that's actually desirable. But for many other beer styles, its not.

DMS control in your finished wort is largely a result of your grist composition, kettle venting, and time between end of boil and wort chilling. If you're using a significant percentage of Pils malt in your grist, DMS production is a real possibility and you need to make sure that you boil and vent effectively for at least the last half hour of the boil and chilling as soon as possible after end of boil. If your grist has little Pils malt, then the concern of developing DMS is reduced considerably, but maybe not eliminated.

If you're brewing something that has little bittering, then a short boil like 30 min could be fine and it will be most gentle to your wort and impart the least aging effects. If you're brewing a typical bittered beer, then a 60 minute boil comes closest to providing bang for your buck. If your beer needs the 'aging' effects of a long boil, then its appropriate to conduct one.

I will reinterate that AHA membership is a worthwhile investment to brewers as a source of real brewing knowledge. AHA members have access to the on-line Zymurgy archive and can review the original article.

 

[50calshooter]

How long do you boil? Why did you decide on that amount?

After 15 years of home brewing and 5 years brewing in my brewpub it's still 60 minutes.

 

[fluketamer]

i boil everything 60 mins.
most conversion occurs in first 20 mins IME anyway.

i think the 90 min thing may be a myth perpetuated from a long time ago when malts were less modified( not sure if this is the right term) i think i read this somewhere.

 

[day_trippr]

"conversion" is generally associated with mashing, not the boil...

Cheers!

 

[Gozie Boy]

I wrote an article on wort boiling in the May/June 2019 issue of Zymurgy that covers this subject.

The bottom line is that hop bittering utilization is pretty well maximized at about the 60 minute mark and its generally a good economic decision to end there...if your goal is imparting adequate bittering with the least time, power consumption, and hop consumption.

Another factor for selecting your boiling duration is the fact that boiling does damage wort and create aged beer effect. In the case of an Old Ale or Barleywine, that's actually desirable. But for many other beer styles, its not.

DMS control in your finished wort is largely a result of your grist composition, kettle venting, and time between end of boil and wort chilling. If you're using a significant percentage of Pils malt in your grist, DMS production is a real possibility and you need to make sure that you boil and vent effectively for at least the last half hour of the boil and chilling as soon as possible after end of boil. If your grist has little Pils malt, then the concern of developing DMS is reduced considerably, but maybe not eliminated.

If you're brewing something that has little bittering, then a short boil like 30 min could be fine and it will be most gentle to your wort and impart the least aging effects. If you're brewing a typical bittered beer, then a 60 minute boil comes closest to providing bang for your buck. If your beer needs the 'aging' effects of a long boil, then its appropriate to conduct one.

I will reinterate that AHA membership is a worthwhile investment to brewers as a source of real brewing knowledge. AHA members have access to the on-line Zymurgy archive and can review the original article.

Always appreciate @mabrungard's insights. This reminds me of something I've wondered about before, and again now that I am about to brew a Belgian Blonde. I boil using a steam condenser/extractor which is very effective. But with a high pilsner beer and DMS potential, I wonder whether I'm eliminating enough precursor, or whether some condenses on the bottom of the lid and drops back into the wort? I typically boil at 38% power in my "Kal" rig with about 0.6 GPH boiloff. This is a lot less than if I did not use the condenser, and with less "venting", so could I be leaving in a lot of DMS precursor?