90 min brew question-

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Jeff20578

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I’m brewing a beer that has a 90 min boil. The 1st hop addition is at 30 - other then boiling off excess liquid, what’s the purpose of a 90 min if you don’t have hop additions close to the start?
 
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Velnerj

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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).
 

Beernik

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Grain bills with a lot of Pilsen malt can develop DMS off flavors of you don’t give them a long enough boil. Another 30 minutes on the boil is cheap insurance against a beer that tastes like creamed sweet corn.
 
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doug293cz

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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).
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.

Traditionally, low kilned malts (Pilsner being the lowest kilned) have more SMM content than higher kilned malts, so have the potential to create more DMS, or leave more residual SMM in the beer, if not enough is converted during the boil. So, historically, brewers have tended to boil high Pilsner content worts longer. It is often claimed that more modern Pilsner malts have less SMM than historical malts, so the need for an extended boil is reduced.

Brew on :mug:
 

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Spikybits

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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
 

doug293cz

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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
Yes, longer boils do darken the wort, but this is usually undesired in Pilsners and other light colored beers.

Brew on :mug:
 

shoengine

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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).
I've gotten that confused before too. Diacetyl causes the butter flavor in beers.
 

Gusso

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90 minutes? I've been doing 30 since my rebirth to brewing last year. Even with lagers, I don't see an issue. It's all I've been doing.
 

doug293cz

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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 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.

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Maillard reactions are reactions between an amino acid and a starch or sugar. They can occur in boiling wort, whereas caramelization cannot.

Both caramelization and Maillard reactions result in darkening.

Brew on :mug:
 

cactusgarrett

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[Maillard reactions] can occur in boiling wort... result in darkening
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?
 
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doug293cz

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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?
"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.

Brew on :mug:
 

dmtaylor

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The reason recipes are written for 90 minute boils though is for fear of DMS. Fortunately, this fear is mostly no big deal for homebrewers in the 21st century. Safe for us to shorten to 60 minutes, or even a little less.

If I wanted darkening and serious Maillard reactions in my beer, I'd be boiling way longer than 90 minutes. Back in the 1800s, a lot of breweries were boiling for 3-8 hours. Beer must have tasted much much different then.
 

Spikybits

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Pretty sure there's something else going on (like concentration) besides the oft cited Maillard Reaction, since that needs temps of 280F+ to occur.
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.
 
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Concentration is an affect of boil off.
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.
 

dmtaylor

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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.
I've actually done this on my last two batches. Usually I am a small batch brewer of about 2 gallons average batch size, and I've always brewed on my stove top, I don't use a big propane burner, etc. But for these two batches, I needed to make 6 gallons for two big events. So I decided to aim for about 1.080 (and I succeeded) with about a 3-gallon batch each, then added distilled water to the fermenter to hit around 1.040. Worked like a charm. Both beers were the best I've made in recent history. Neither had significant darkening or caramel flavor effects, not at all.
 

cactusgarrett

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Sources? Alot if not most sources do cite maillard reaction as occuring with a longer boil.
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...
 

doug293cz

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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.
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 :mug:
 
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Not an issue for extract brewing
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.
 

Steveruch

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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.
 
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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.
Understood. I've seen your "no boil (pasteurized)" recipes in Zymurgy.

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?
 
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doug293cz

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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 :mug:
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.
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.

Brew on :mug:
 

doug293cz

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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?
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.

I have heard that some large commercial breweries do concentrated boils, but they may also be using filter presses to lauter the mash, which can give you lauter efficiencies in the high 90%s. So, if you look at the total cost of production per gallon, the money saved on energy to boil, and the increased equipment capacity, makes up for the small loss of lauter efficiency (when using a filter press.) Without a filter press, the lauter losses are larger for a concentrated boil, so not attractive from a system standpoint.

Brew on :mug:
 
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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.
 

dmtaylor

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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.
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. Or perhaps if you do a very small boil volume and add the vast majority of your water after the boil is complete.
 
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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).
 

dmtaylor

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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).
Stale extract adds an oxidized twang, which I would categorize as likewise caramel, with wet cardboard, a tanginess, and perhaps sort of metallic although that latter part might be more due to not using distilled water and thus doubling up on all the minerals in the finished beer.
 
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Thanks again.

I'll (attempt to) close out this 'side topic' with a plan to brew an Amber Ale with DME using a 2x concentrated boil (OG 88-ish, SG 44-ish in fermenter). Not sure when I'll get to it as I need to order some Amber DME. I suspect that this is a "low risk" experimental brew and that I'll get an enjoyable beer with no "unexpected" or "off" flavors.
 

Beermeister32

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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…!
 

shoengine

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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…!
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.
 
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