Boil time reduction : the science please

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I linked an easy-to-read article that reminds us why we bother to boil wort. Home brewers invariably use pretty simple kettles which boil open at 100°C. If you wish to maintain the full benefits of boiling wort whilst reducing boil time to 30 min, you'll need to do what many commercial brewers do, boil at about 110°C.
 
I see what looks vaguely like a 'table of contents' for an issue of a journal. Apparently the article is behind a paywall (or login or something :agressive:). Maybe it's worth the effort of those reading on the primary topic to figure it out. 🤷‍♂️



Back to pellet hops, I'm still curious as to if there are other articles (journal science, citizen science, random musings) that support or challenge data presented earlier.
 
Don't homebrew discussions about shorter boils, going back to the 00s, refer to 60-min boils? The full benefits of boiling wort, including stabilising the product, aren't necessarily promoted by very short boil times. If I used an extract kit - that's already been boiled - and had some hop extract, I might consider a very short boil.
If I make an extract pale ale I only boil 15 minutes and just double my hops. 5gal batch, 2 ounces at 15, 2 ounces at 10 and 2 ounces at flameout. A 3 gallon batch instead gets an ounce at those times.
 
If I make an extract pale ale I only boil 15 minutes and just double my hops. 5gal batch, 2 ounces at 15, 2 ounces at 10 and 2 ounces at flameout. A 3 gallon batch instead gets an ounce at those times.
Extract has already had the Jesus boiled out of it, to be fair. With a little hop extract, you could probably get away with no boil, if pitching yeast well enough.
 
There's this from David Heath. Nothing very scientific, just showing how to adjust the IBUs of the bittering hops when moving them up to the 30 minute mark. From some of his other videos it seems Dave has had a pretty long career in pro brewing and home brewing, so I figured maybe his experience was worth considering.




I tried this on my recent brew and didn't notice anything different from when I had done the same recipe at 60 minutes. If I can shorten my brew day without sacrificing taste, I'll start doing it this way going forward.
 
David Heath is a double-glazing salesman. A con artist. He works for a dodgy home-brew shop backed by parasitic investors in Norway. Not content with competing on price and value, for the home brewer, these profiteering barbarians are positioning themselves to control and manipulate the wholesale business locally. Selling cheap Chinese crap like it were quality German engineering.
 
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Extract has already had the Jesus boiled out of it, to be fair. With a little hop extract, you could probably get away with no boil, if pitching yeast well enough.
Yes the extract has had the crap boiled out of it. My point is that instead of boiling for 60 minutes to bitter that you can boil much less and just pump up the hop quantities and get a great beer.
 
Yes the extract has had the crap boiled out of it. My point is that instead of boiling for 60 minutes to bitter that you can boil much less and just pump up the hop quantities and get a great beer.
If that satisfies you, great, for you.
 
I tried this on my recent brew and didn't notice anything different from when I had done the same recipe at 60 minutes. If I can shorten my brew day without sacrificing taste, I'll start doing it this way going forward.

There's a 'back of the envelope" calculation that suggests changing from a 60 minute boil to a 30 minute boil requires about 25% more hops. Some details to support the calculation can be found here (link, no paywall). One should also adjust water volumes to account for less boil off.

There's bunch of us over in "I Brewed A Favorite Recipe Today (link)" that have been doing extract-based 30 min boils for a while. I haven't done a 60 min boil with DME for probably 4 years.

eta: link(s)
 
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There's a 'back of the envelope" calculation that suggests changing from a 60 minute boil to a 30 minute boil requires about 25% more hops. Some details to support the calculation can be found here (link, no paywall). One should also adjust water volumes to account for less boil off.

There's bunch of us over in "I Brewed A Favorite Recipe Today (link)" that have been doing extract-based 30 min boils for a while. I haven't done a 60 min boil with DME for probably 4 years.

eta: link(s)


I used Brewfather for that brew day. What I done, per the David Heath video, was change the boil time from 60 minutes to 30. This adjusted for the boil off so I could calculate my salt additions per adjusted water volume. The main thing to look for would be to make note of what your bittering hop's IBU amount is in a 60 minute boil, then bump up the IBU amount after changing the boil off to match. Hop additions that are 30 minutes or less are left as is.

The beer is still fairly young, It's only been kegged for about 2 weeks. I'm hoping it improves with time. It doesn't taste bad, but I'm just not "wowed" either. I didn't dry hop because after I pitched the yeast, I went out of town on vacation for about a week, came back, then kegged it. Maybe that's my problem. Meh....I'll just brew it again and see what happens.

The short of it is I can't tell the difference with this version vs prior 60 minute boil versions, so the shorter brew day wins out.
 
We poured this weekend at a beer festival and we used a 30 minute boil for all the beers we made. It was done as a time saving measure in order to prepare everything that we wanted to make for the event.

There was no noticeable difference in the flavors of the beer we poured and most seemed to like it. The adjustments we made were to the water amounts and hop additions.

We had a problem with one beer but it was related to fermentation. We rushed it along when we shouldn’t have. We ended up not serving it.

We brew on a 50l Speidel system. Everything worked well for us. We’ll probably go back to 60 minute boils again but this was nice, as we were able to get everything together in a shorter amount of time with no ill effects.

We only looked in to it at a cursory level. Based on our real world experience it was great.
 
I mainly brew IPAs(all kinds) and dropped my boil time to 45 minutes long ago and it seems to work fine. I bet I could go even lower with no noticeable changes. It would be a good experiment to brew identical batches at different boil times, if I could ever bring myself to brew the exact same batch two times.

Doesn't really affect my hop usage as almost all of my hops go in later than that anyways. I'm not interested in carmelized flavors that may come from a long boil.

I usually still do 60 when I brew a pilsner although I would really doubt that makes a difference either.
 
I have always boiled for 90 minutes although the hops are not necessarily added until the boil has been going for half an hour. I'm convinced boiling isn't just to extract matter from hops. It does make for a later finish on brew day, but my beer is usually bright and ready to drink 8 or 9 days later.
 
What are brewers here actually comparing with, a memory of previous beers boiled for standard times? Without any bias creeping in? Belief? Brulosophy? I'll stick with what the science proposes as much as possible, but I appreciate not everyone is willing to accept reason over superstition.
 
What are brewers here actually comparing with, a memory of previous beers boiled for standard times? Without any bias creeping in? Belief? Brulosophy? I'll stick with what the science proposes as much as possible, but I appreciate not everyone is willing to accept reason over superstition.
I have a very simple process for validating the success of a tweak of my brewing technique. I ask myself the following question:

Does my beer still taste great?

Yes = good idea!
No = bad idea!
Tastes even better = marvelous idea!
 
No science only anecdotaly from me. I'm a 90 minutes boiler like a few others here. I used to do 30 to 60 minutes when I started brewing but was never really that happy with my beer, they were OK but no wow. Started to go 90 minutes and immediately got what I thought was missing from the shorter boils, just that extra punch in flavour.
 
No science only anecdotaly from me. I'm a 90 minutes boiler like a few others here. I used to do 30 to 60 minutes when I started brewing but was never really that happy with my beer, they were OK but no wow. Started to go 90 minutes and immediately got what I thought was missing from the shorter boils, just that extra punch in flavour.
I will run this one through my evaluation process!
 
I have a very simple process for validating the success of a tweak of my brewing technique. I ask myself the following question:

Does my beer still taste great?

Yes = good idea!
No = bad idea!
Tastes even better = marvelous idea!
That's absolutely fine and, of course, home brewers are free to brew however they please. It just isn't very scientific. Quite the opposite, in fact. Superstition. As humans - with pretty impressive simulators between our ears - we're all pathetically biased as individuals*. That's why we had to develop the scientific method. The brewing process as we know it - as developed by scientific endeavour - isn't ever going to be challenged seriously by superstitious home brewers. If a 30-minute boil were better overall we'd all be doing 30-minute boils. At no point does "it's more convenient for me" challenge the knowledge that's accumulated thanks to the science of brewing.
 
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That's absolutely fine and, of course, home brewers are free to brew however they please. It just isn't very scientific. Quite the opposite, in fact. Superstition. As humans - with pretty impressive simulators between our ears - we're all pathetically biased as individuals*. That's why we had to develop the scientific method. The brewing process as we know it - as developed by scientific endeavour - isn't ever going to be challenged seriously by superstitious home brewers. If a 30-minute boil were better overall we'd all be doing 30-minute boils. At no point does "it's more convenient for me" challenge the knowledge that's accumulated thanks to the science of brewing.
Nope, not going down that route.
 
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I use neither. Are you confusing me with someone else?

Sorry, I tried to be funny, but I didn't made myself clear. And I had to edit the post several times because got some problems trying to insert the pictures.

Anyway, was a splited batch and the first beer was fermented with BE-134 and the second, the hazy one, with Voss Kveik. Because you post somewhere else that you don't like it, I quoted you, given some characteristics of it, instead just naming it. And you was right, isn't a super yeast. Beer tastes like orange peel, it's acid and doesn't clear, even with a high floculation rate. Seriously, it stock at fermenter's bottom.

So... Yeast could influence beer's clarity.
 
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I brewed yesterday to try using up some whole hops. I have one large paint bag for the hops in the boil. I normally use pellets for bittering I just toss in the boil, but used the bag for bittering with some whole hops. I decided to remove the bittering whole hops after 40 min of a 60 boil and put in flavor hops in that bag. I was wondering if that effects the bittering, but decided by that time not much I guess.
How much time does it take for the lupulin to dissolve from whole hops?
 
Hops, schmops; it's all about the DMS. If you end up with too much DMS in your finished beer (with a style not forgiving of it), it's more or less ruined. Why screw around? Half-life of SMM is just over half an hour, so a 60-minute boil is about twice as good as a 30-minute boil, and 90 minutes twice as good again. And it should be a full, rolling boil to get rid of volatiles effectively.
 
Half-life of SMM is just over half an hour, so a 60-minute boil is about twice as good as a 30-minute boil, and 90 minutes twice as good again. And it should be a full, rolling boil to get rid of volatiles effectively.

Just a little math check. Assuming a half life of 30 minutes, a 60 minute boil would convert 50% more than 30 minutes (i.e. only half as much conversion from 30 to 60 as from 0 to 30). 90 minutes would convert 75% more than 30 minutes (i.e. only 75% as much from 30 to 90 as from 0 to 30).
 
Just a little math check. Assuming a half life of 30 minutes, a 60 minute boil would convert 50% more than 30 minutes (i.e. only half as much conversion from 30 to 60 as from 0 to 30). 90 minutes would convert 75% more than 30 minutes (i.e. only 75% as much from 30 to 90 as from 0 to 30).
I think this is semantic? Every ~30 (37 or so) minutes you lose half the DMS, and I call that twice as good. If you're just at the taste threshold at 90 minutes, you'd have been double the threshold at 60 and quadruple at 30.
 
I don't have the journal article at hand but I recall reading studies that longer boil times (in excess of ninety minutes were tested) gave a far more bitter impression than sixty or ninety minute boils. The authors concluded boiling hop matter for longer periods of time extracted more compounds that broke down into unpleasant bitterness. That's not a direct relationship between sixty or ninety versus thirty but there are definitely changes to the beer over the length of the boil beyond just evaporation and isomerization.

There is no absolute answer to what anybody should or should not do. It depends a lot on the goal for a given beer along with the ingredients and processes used.
 
I think this is semantic? Every ~30 (37 or so) minutes you lose half the DMS, and I call that twice as good. If you're just at the taste threshold at 90 minutes, you'd have been double the threshold at 60 and quadruple at 30.

I see what you're saying. If "twice as good" means half as much remaining SMM than at the end of the previous 30 minute interval, I agree. I originally read "twice as good" to mean twice as much SMM was converted every 30 minutes, which of course isn't the way half life works.
 
I too wish I knew the concrete science... So often what we accept as brewing gospel turns out to not be true.

They would be the first to admit it's not science, but the Short & Shoddy brews at Brulosophy have convinced me that you can probably get away with really short boils, under 30 minutes, even for pilsners.

With that said, I personally would never do it. It's not science, but my gut tells me those Short & Shoddy beers are probably quite decent, but might be even better if boiled a bit longer. I get the feeling they are drinkable, but not world class. So, if the goal is to make the BEST beer you possibly can, I think it's a better bet to at least boil for 60.

Currently, I at least do 75 minutes, and usually just make it 90 because I almost always have pils in the grain bill. What's an extra 15-30 minutes for a 5+ hour brew day? If there's even a chance the extra time helps ensure low DMS then I'll take that chance.

Again not science, but I feel my beers turn out better with the longer boils. They sometimes do well in competitions, which counts as measurable "science" to me!
 
Apologies if this takes the discussion off course, but one thing I think of from time to time is the concentration of flavor-perception ions in the wort (sodium, chloride, sulfate) as we boil.

We use these calculators to designate a profile we want for the mash ... but then after the mash we boil anywhere from 30 minutes to 90 minutes. Can we assume that the concentration of sodium, chloride and sulfate will be appreciably higher in the end product when undergoing at 90 minute boil vs. a 30 minute boil (or no boil!) ? I've looked for boil impact info on water chemistry and have come up empty.

And wouldn't this be even more impactful in a small batch of, say, 3 gallons; if we start with 4 gallons of wort and boil off a gallon to finish with 3, are we not increasing the concentration of these ions by 33%? (xx ppm @ 4 gallons = xx*1.33 at 3 gallons).

Does this even matter??
 
Apologies if this takes the discussion off course, but one thing I think of from time to time is the concentration of flavor-perception ions in the wort (sodium, chloride, sulfate) as we boil.

We use these calculators to designate a profile we want for the mash ... but then after the mash we boil anywhere from 30 minutes to 90 minutes. Can we assume that the concentration of sodium, chloride and sulfate will be appreciably higher in the end product when undergoing at 90 minute boil vs. a 30 minute boil (or no boil!) ? I've looked for boil impact info on water chemistry and have come up empty.

And wouldn't this be even more impactful in a small batch of, say, 3 gallons; if we start with 4 gallons of wort and boil off a gallon to finish with 3, are we not increasing the concentration of these ions by 33%? (xx ppm @ 4 gallons = xx*1.33 at 3 gallons).

Does this even matter??


Good question. My guess is, the amount of time these additions spend in boiling wort vs what the amount of wort left after the boil is over would be the deciding factor. When I changed my last recipe for a 30 minute boil in Brewfather, my water additions were scaled accordingly. So I think the addition amount boiling for 30 vs 60 or 90 might be what should be considered.
 
And wouldn't this be even more impactful in a small batch of, say, 3 gallons; if we start with 4 gallons of wort and boil off a gallon to finish with 3, are we not increasing the concentration of these ions by 33%? (xx ppm @ 4 gallons = xx*1.33 at 3 gallons).

Yes, the concentrations are inversely proportional to volumes.
 
I too wish I knew the concrete science...
The information is available in text books and journals. If I were to pursue this, I would anticipate that it would cost between $500 and $1000 (USD) over 18 to 24 months. At the moment, the ROI (for me) is not favorable. I suspect that the core of this information is available in a couple of modern (later than 2015) home brewing books and subscription web sites - and that's probably $200 and 12 months time. (I haven't done the former to confirm the latter).
 
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Apologies if this takes the discussion off course, but one thing I think of from time to time is the concentration of flavor-perception ions in the wort (sodium, chloride, sulfate) as we boil.

We use these calculators to designate a profile we want for the mash ... but then after the mash we boil anywhere from 30 minutes to 90 minutes. Can we assume that the concentration of sodium, chloride and sulfate will be appreciably higher in the end product when undergoing at 90 minute boil vs. a 30 minute boil (or no boil!) ? I've looked for boil impact info on water chemistry and have come up empty.

And wouldn't this be even more impactful in a small batch of, say, 3 gallons; if we start with 4 gallons of wort and boil off a gallon to finish with 3, are we not increasing the concentration of these ions by 33%? (xx ppm @ 4 gallons = xx*1.33 at 3 gallons).

Does this even matter??
I asked this question when planning a long boil for a barleywine. As I recall, Martin’s answer was yes, definitely adjust ion concentrations for the final (post boil) volume.

Except calcium. Enzymes need it in the mash, so target at least 50 ppm at mash concentration.

Edit: this thread.
Edit #2: it was a ryewine. And it was not a good idea.
 
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The information is available in text books and journals. If I were to pursue this, I would anticipate that it would cost between $500 and $1000 (USD) over 18 to 24 months. At the moment, the ROI (for me) is not favorable. I suspect that the core of this information is available in a couple of modern (later than 2015) home brewing books and subscription web sites - and that's probably $200 and 12 months time. (I haven't done the former to confirm the latter).
Interesting ROI calc. If there is a homebrew book I haven't read I would sure like to know it. I must have read them all by now.... Though I haven't read textbooks...

Also, what are the paid sites?! Maybe I shouldn't be wasting my time on this free one! JK, LOL.

But you are right that the ROI probably is not even worth it. If 30 minute boils work for folks, then go for it. For now I'm sticking with 60 - 90.
 
If you want me to mix the pot even further I brewed 2 allgrain 5 gallon beers today and was pitched and cleaned up in 5.5 hours due to mash hopping and only pasteurized the beer while whirlpooling hops for a NEIPA and then cut the west coast to a 30 min boil. By doubling the 30 min addition.

As a father with 2 boys under 3.5 years old, doing so allows me to be done faster which keeps my wife amusing my hobby lol. I’ve also medaled multiple times with reduced boil times and even no boils in decent sized regional comps
 
I asked this question when planning a long boil for a barleywine. As I recall, Martin’s answer was yes, definitely adjust ion concentrations for the final (post boil) volume.

Makes sense on something like that ryewine (er, ryewine syrup!)

But it's interesting that most of the calculators (at least the ones I'm familiar with: Bru'n Water, EZ Water Calculator, Brewer's Friend) don't take boil time or boil off rate into account. Or maybe they do; maybe the suggested ppm values for the common water profiles are based on the assumption there will be a 15-20% increase in concentration in those ions in a 5-6 gallon batch and a 1.0-1.5g boil off rate/hr.??
 
I haven't noticed water adjustment calculators accounting for boil-off rates. Beer style and mash volume are the drivers; controlling mash pH and promoting conversion/enzyme activity being the aim. I know my sparge water dilutes my water treatment more than my boil-off rate concentrates it. And I suspect at least some ions are lost in trub. Generally very difficult to predict, when we think about it, which is probably why boil-off rate isn't considered in water calculators. I"d be very suspicious of any claiming to have this under control. What are they basing it on, BS, suspicious error margins and winging it?
 
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If, as I have suggested elsewhere, mineralization was based upon mEq's instead of ppm's (mg/L's), then boil-off would be meaningless, as mEq's of mineralization do not change as a consequence of boil-off.
 
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