[gymrat]

I read on another forum that you should always boil your wort 90 minutes. Is this really necessary or can I get by with bringing to a boil and going right into my 60 minute hop addition?

[bluesman]

A 90 min boil is preferred when using Pils malt. The longer boil volitalizes the DMS causing it to outgas from the wort.

A longer boil is also preferred with high gravity beers in that it will enable the production of melanoidins and will generate maillard reactions which enhance the flavor and color of the finished beer.

[tygo]

Boiling for 60 minutes is mostly fine.  If you're using a large portion of pilsner malt you may want to go up to 90 minutes to drive off additional DMS precursors.  Or you may want to boil longer if your objective is to concentrate the wort down more, such as when you're doing a wee heavy.

[jwaldner]

As I understand the boil process, the boil time can be dependent on the malt you're using to eliminate Dimethyl Sulfide or DMS.  For an American 2-Row, a 60 minute roiling boil should be sufficient.  However, if you're using a malt such as Pilsner with a DMS pre-cursor a 90 minute vigorous boil will work better to help eliminate any DMS.

There are also many other factors to consider in your boil time but this is one of the primary reasons I use to shorten/lengthen my boil time.

Cheers!

[denny]

99% of the time I do only a 60-70 min. boil, even with pils malt.  I haven't had any DMS issues, so I don't feel like I need to compensate for them.  Every once in a while I get crazy and do a 90 min. boil just to see if I can tell the difference.

[jeffy]

99% of the time I do only a 60-70 min. boil, even with pils malt.  I haven't had any DMS issues, so I don't feel like I need to compensate for them.  Every once in a while I get crazy and do a 90 min. boil just to see if I can tell the difference.

I use a lot of pils malt and don't have issues resulting from a 60 minute boil either.  Having a good rolling boil and making sure no condensation falls back into the wort is good practice.

[bluesman]

The one factor to consider with DMS production is cooling time. The longer it takes to cool the wort the higher the production of DMS in the hot wort.

As the wort is boiling, it is driving off the precursers used to generate DMS, so when the boiling action stops and the cooling process starts, the precursers are no longer being driven off therefore enabling the generation of DMS.

 

[bluesman]

I use a lot of pils malt and don't have issues resulting from a 60 minute boil either.  Having a good rolling boil and making sure no condensation falls back into the wort is good practice.

I agree in that the intensity of the boil is a factor in driving off the volatiles responsible for DMS formation. I believe there is a correlation between the intensity of the boil and the amount of precursers that can be driven off during the boil which will inevitably impact the amount of time required to drive off the SMM and other precursers of DMS.

[hopfenundmalz]

The one factor to consider with DMS production is cooling time. The longer it takes to cool the wort the higher the production of DMS in the hot wort.

As the wort is boiling, it is driving off the precursers used to generate DMS, so when the boiling action stops and the cooling process starts, the precursers are no longer being driven off therefore enabling the generation of DMS.

One can wait a long time if the boil is long enough and intense enough.  I have been doing some 45 minute hop steeps after knockout, no DMS.  This has not been tried with Pils malt, but that should work too.

Edit - the pros have the wort in the whirlpool for a long time, sometimes it takes an hour before the wort is all through the chiller.

[bluesman]

The one factor to consider with DMS production is cooling time. The longer it takes to cool the wort the higher the production of DMS in the hot wort.

As the wort is boiling, it is driving off the precursers used to generate DMS, so when the boiling action stops and the cooling process starts, the precursers are no longer being driven off therefore enabling the generation of DMS.

One can wait a long time if the boil is long enough and intense enough.  I have been doing some 45 minute hop steeps after knockout, no DMS.  This has not been tried with Pils malt, but that should work too.

Edit - the pros have the wort in the whirlpool for a long time, sometimes it takes an hour before the wort is all through the chiller.

I'm not doubting your results Jeff, nor those af any commercial brewers.

There are so many other factors to consider that could come into play with this regard (boil time, boil vigor, cooling time, fermentation, etc...) that it would be hard to nail down any one factor as limiting in a given beer without isolating one variable at a time in controlled experiments. Knowing all of the facts and understanding how they can be manipulated to produce a given result is a very challenging. It is known that there are precursers in the wort during the boil and these precursers aid in the formation of DMS under the right conditions. Eliminating and/or reducing this compound is process dependant.

I believe the best way to understand DMS and it's effect is to experience it first hand and then mitigate it by extending the boil or increasing the boil vigor and so on.  

[denny]

I believe the best way to understand DMS and it's effect is to experience it first hand and then mitigate it by extending the boil or increasing the boil vigor and so on.  

I absolutely agree, Ron.  I find that's true of most of the things about homebrewing.

[hopfenundmalz]

The one factor to consider with DMS production is cooling time. The longer it takes to cool the wort the higher the production of DMS in the hot wort.

As the wort is boiling, it is driving off the precursers used to generate DMS, so when the boiling action stops and the cooling process starts, the precursers are no longer being driven off therefore enabling the generation of DMS.

One can wait a long time if the boil is long enough and intense enough.  I have been doing some 45 minute hop steeps after knockout, no DMS.  This has not been tried with Pils malt, but that should work too.

Edit - the pros have the wort in the whirlpool for a long time, sometimes it takes an hour before the wort is all through the chiller.

I'm not doubting your results Jeff, nor those af any commercial brewers.

There are so many other factors to consider that could come into play with this regard (boil time, boil vigor, cooling time, fermentation, etc...) that it would be hard to nail down any one factor as limiting in a given beer without isolating one variable at a time in controlled experiments. Knowing all of the facts and understanding how they can be manipulated to produce a given result is a very challenging. It is known that there are precursers in the wort during the boil and these precursers aid in the formation of DMS under the right conditions. Eliminating and/or reducing this compound is process dependant.

I believe the best way to understand DMS and it's effect is to experience it first hand and then mitigate it by extending the boil or increasing the boil vigor and so on.  

The boils I use for ales are a little over 60 minutes often more like 70-75 min., and vigorous.  I have also been leaving the lid off, and the hot wort still has vapor coming off.  Have not tried it with the lid on, but why mess with it?  The wort is at ~175F after 45 minutes (10 gallon batches) so it should still be sanitary.  Then chill it, transfer, add O2, and pitch the yeast,

[troy@uk]

The other issue to consider other than DMS is hot break.  I have heard that if your first hopping is @ 60 min, you may want to consider boiling for approx 10 - 15 min to allow your hot break to form before adding hops to insure expected utilization, so this would give you a total of about a 75 min boil.

This brings up another related question that I just came across.  I was listening to Brew Strong and read in Brewing Better Beer about late hop additions.  I made an APA with my earliest addition being @ 20 min.  The beer was GREAT!!!  My question is since it has no Pils and I am not too concerned about DMS, could I just do a 35 min boil?

[astrivian]

A longer boil is also preferred with high gravity beers in that it will enable the production of melanoidins and will generate maillard reactions which enhance the flavor and color of the finished beer.

So would you still boil for 90mins for a Belgian Golden Strong or a tripel or would it make the final color to dark?

[tubercle]

The other issue to consider other than DMS is hot break.  I have heard that if your first hopping is @ 60 min, you may want to consider boiling for approx 10 - 15 min to allow your hot break to form before adding hops to insure expected utilization, so this would give you a total of about a 75 min boil.

IMHO, its always best to bring to a boil, let the hot break thing happen and get things under control and adjusted before worring about hops and such. Too many things going on at once and you might get hurt or have a bunch of baked on wort on the outside of your pot to deal with. Start you timing with hops and such after things settle down. Nobody alive can tell the difference between a 60 & 65 minute boil.