DMS and diacetyl are unrelated. You are correct that 90 minute boils have traditionally been recommended to minimize DMS in beer, which causes a "cooked corn" or "cooked vegetable" off flavor. Boiling wort slowly converts preexisting SMM into DMS. It takes 30 - 40 minutes to convert half of the remaining SMM to DMS (depending on wort pH.) The DMS formed evaporates rapidly, as it's boiling point is about 100°F. Residual SMM can convert to DMS during slow cooling or other storage conditions, so getting rid of as much SMM as possible during the boil reduces the potential for formation of DMS in the beer after the boil.There's a belief out there that pilsner malt will produce DMS. Which is a precursor to diacetyl and a 90 min boil will get rid of all DMS avoiding the dreaded diacetyl in the finished product.
Many brewers these days don't find this to be true with modern modified malts.
I've never done a 90 min boil and I haven't had any issues (there's my anecdotal experience).
Yes, longer boils do darken the wort, but this is usually undesired in Pilsners and other light colored beers.other reason for 90 min boil is to enhance the maillard reaction which darkens the wort - i believe 90 min boil will also enhance some caramel favors but this is anecdotal
Yep, agreed but OP just said a beer!Yes, longer boils do darken the wort, but this is usually undesired in Pilsners and other light colored beers.
Brew on
I've gotten that confused before too. Diacetyl causes the butter flavor in beers.There's a belief out there that pilsner malt will produce DMS. Which is a precursor to diacetyl and a 90 min boil will get rid of all DMS avoiding the dreaded diacetyl in the finished product.
Many brewers these days don't find this to be true with modern modified malts.
I've never done a 90 min boil and I haven't had any issues (there's my anecdotal experience).
Yes. Duplicate threads.Did this thread just get merged? Otherwise there is a in the Matrix...
Pretty sure there's something else going on (like concentration) besides the oft cited Maillard Reaction, since that needs temps of 280F+ to occur.other reason for 90 min boil is to enhance the maillard reaction which darkens the wort
I think you are referring to "caramelization", which does require temps hotter than boiling, but different sugars have different onset temps for caramelization. Caramelization is driven strictly by temperature.Pretty sure there's something else going on (like concentration) besides the oft cited Maillard Reaction, since that needs temps of 280F+ to occur.
I used to just blindly accept when people suggested that Maillard was at play until, in one of the plethora of podcasts I spend too much time listening too, I vaguely remember a pro brewer suggesting this isn't the case because the temps weren't hot enough. The reason I looked into it closer and saw (you quoted the same reference I did) " The reaction is a form of non-enzymatic browning which typically proceeds rapidly from around 140 to 165 °C (280 to 330 °F)"[Maillard reactions] can occur in boiling wort... result in darkening
"proceeds rapidly" is the important qualifier. Most chemical reactions follow what's known as Arrhenius temperature rate behavior. In summary, the rate of reactions increases exponentially as the inverse of the absolute temperature decreases. This means that there is not a specific temperature at which the reaction starts to occur, but rather that it pretty much occurs to some degree at all temperatures, just significantly slower at lower temps. You get more reaction at lower temps with low activation energy processes than with high activation energy processes. In the context of "proceeds rapidly" for Maillard reactions, I would take that to mean that you see visible results in just a few minutes. With boiling wort we are talking about a time frame of an hour +/-, and less dramatic darkening than the browning of a loaf of bread.I used to just blindly accept when people suggested that Maillard was at play until, in one of the plethora of podcasts I spend too much time listening too, I vaguely remember a pro brewer suggesting this isn't the case because the temps weren't hot enough. The reason I looked into it closer and saw (you quoted the same reference I did) " The reaction is a form of non-enzymatic browning which typically proceeds rapidly from around 140 to 165 °C (280 to 330 °F)"
What am I missing?
What am I missing?
Sources? Alot if not most sources do cite maillard reaction as occuring with a longer boil. Concentration is an affect of boil off. Most brewers account for boil off rates and will start with a certain amount of liquid prior to boil to achieve a specific amount going into the fermentor.Pretty sure there's something else going on (like concentration) besides the oft cited Maillard Reaction, since that needs temps of 280F+ to occur.
There is also the idea of a "concentrated" boil - where the boil SG is much higher than the target OG in the fermentation vessel.Concentration is an affect of boil off.
One could also do this (concentrated boil) with an "all grain" wort: mash a SG 88 wort, then dilute it to OG 44 in the fermentation vessel. FWIW, I did a "one-off" BIAB Red Ale (OG 42-ish) using an OG 75 wort. The beer "came out fine". The color was "to style". No "unexpected" flavors.
It's right there in the link I included and further quoted. However, Doug did a good job of explaining that despite boiling wort being below the temp cited, it's a rate of reaction thing. Since I've been brewing for longer than I care to mention, I'm trying force myself to give some critical thinking behind the info that people pass down. Previously, a lot if not most sources also said to transfer to a secondary...Sources? Alot if not most sources do cite maillard reaction as occuring with a longer boil.
You can certainly do a concentrated wort boil when doing all grain, but your lauter efficiency, and therefore both mash and brewhouse efficiency, will take a hit. Not an issue for extract brewing because there is no lauter step involved.There is also the idea of a "concentrated" boil - where the boil SG is much higher than the target OG in the fermentation vessel.
With DME/LME, one can add half the water and all the extract at the start of the boil. This results in a boil SG that's roughly 2x the recipe OG. It apparently also leads to wort that is "darker" than expected and has "unexpected" flavors.
One could also do this (concentrated boil) with an "all grain" wort: mash a SG 88 wort, then dilute it to OG 44 in the fermentation vessel. FWIW, I did a "one-off" BIAB Red Ale (OG 42-ish) using an OG 75 wort. The beer "came out fine". The color was "to style". No "unexpected" flavors.
With "extract", there is a observation in How To Brew, 4e (chapter 9) that concentrated boils lead to "wort darkening and the development of off flavors". I didn't see any additional details.Not an issue for extract brewing
That can be countered by boiling for a shorter time. Or not at all; extract doesn't have to be boiled.With "extract", there is a observation in How To Brew, 4e (chapter 9) that concentrated boils lead to "wort darkening and the development of off flavors". I didn't see any additional details.
That can be countered by boiling for a shorter time. Or not at all; extract doesn't have to be boiled.With "extract", there is a observation in How To Brew, 4e (chapter 9) that concentrated boils lead to "wort darkening and the development of off flavors". I didn't see any additional details.
My observation (quoted above) that you replied to, was strictly about lauter efficiency effects. Did not address wort darkening at all. They are two completely separate topics.You can certainly do a concentrated wort boil when doing all grain, but your lauter efficiency, and therefore both mash and brewhouse efficiency, will take a hit. Not an issue for extract brewing because there is no lauter step involved.
Brew on
With "extract", there is a observation in How To Brew, 4e (chapter 9) that concentrated boils lead to "wort darkening and the development of off flavors". I didn't see any additional details.
Obviously, wort darkens when boiling. How much? The numbers from the presentation (above) suggest "not much".
Hard to have a discussion about "off flavors" that don't have specific names.
Concentrated boils are most often used with extract brews, as they allow batches larger than the available boil kettle to be brewed. They are very infrequently done for all-grain, probably due to the efficiency hit....
eta: my curiousity/questions are about understanding concentrated boils (boil SG 88-ish, target OG 44-ish). If a concentrated 60 min boil (the Amber Ale I mentioned) works with 'all-grain' wort, would it also work with fresh DME/LME?
I'm still curious about the specific names of the 'off' flavors that How To Brew, 4e (chapter 9) hints can occur when doing concentrated boils with extract.
Thanks!Caramel and burnt extract are possible... but mostly only if you don't remove from the heat and/or stir really well when adding the extract in.
Thanks!
Those would be faults in the implementation of the process (and not faults inherit to fresh ingredients).
There are also number of (named) off flavors associated with 'stale' LME. Those would be ingredient handling faults (and not related directly to concentrated boils).
For me it comes down to my goals, and a shorter boil is never really one of my goals. I know some people have really tight time restrictions and I'm glad they get good results but when I brew I usually dedicate all day to it so saving half an hour or an hour doesn't do much for me.One other thing to mention is different people will detect DMS, other people don’t.
I can detect DMS easily, never an issue with a 90 minute boil. Consider it best practices with Pilsner malt. Anecdotally, there are a lot of people who swear by 60 minute Pilsner boils. For me, I’ll stick with the 90 minute when using Pilsner malts. Good insurance…!
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