Cost of the boil.

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Brew_DD2

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He’s giving home brewers help and advice and getting abused what a sad world the internet is.

There's a hell of a lot of jealousy involved, as well as some really weird partisan ****. I honestly don't get why people get so unpleasant. I really enjoy most of his content, even if I do beg to differ on some stuff, but I wouldn't dream of bad-mouthing the guy.
 

foxy

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I’ve been watching David Heath on YouTube this evening the two blogs were his job and background and the 30 minute boil. He comes across as a really nice guy telling good dvice.
Are we still talking about the cost of the boil? Start another thread don't hijack this one.
 

Sadfield

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Indeed, the video was brought into the debate in post #71 by the proponents of short boiling. It's content was rightly questioned for being short on any facts or evidence to support the claims within.

Those questions haven't been answered with anything more substantial than 'I do it, and don't notice a difference'. It's laughable that disagreeing with those that subscribe to Dave Heaths unsubstantiated opinions on short boiling, leads to strange accusations of abusive, jealous, hate. Not partisan in any way are we.
 

Agentgonzo

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Indeed, the video was brought into the debate in post #71 by the proponents of short boiling.
Again, facts seem to get twisted to suit the narrative. Whilst #71 was my post, I'm not one of the proponents you're arguing with and haven't advocated a shortened boil.
 
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foxy

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I don't think he's hijacked the thread at all.
Here's the David Heath 30 minute boil video:


Unfortunately it is a known fact that somewhere between 80 to 90% of the population are gullible. Putin controls 80% Russian population through their belief of what is being broadcast must be true. Religion for 2,000 years has relied on the gullible. It is no different to an accounts clerk in a wholesale company of home brew equipment to tune in to the gullibility of home brewers.
A well known quote. Believe nothing, question everything and assume nothing'
Good luck to David Heath with his videos, he is only trying to keep the wolf from the door.
I think I have asked this before, can anyone show any evidence where a qualified brewer, never mind a Master Brewer, endorses a 30 minute boil?
Don't believe everything another home brewer tells you. Research your self.
 

Sadfield

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Again, facts seem to get twisted to suit the narrative. Whilst #71 was my post, I'm not one of the proponents you're arguing with and haven't advocated a shortened boil.
Fair enough, but was posted in response to the debate on 15-30 minute boils, so an easy link to make. And it was immediately taken on by those that do in post #72.
 

Agentgonzo

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This thread has made me learn far more about the chemistry of the boil than I ever thought I would be interested in!
Don't believe everything another home brewer tells you. Research your self.
I don't dispute any of the research into boil times and DMS, but I couldn't explain the dichotomy between the research saying that you need the 60 minute boil, and the significant number of homebrewers (here and elsewhere) saying they can't tell the difference/can't taste DMS on short boils. I think it is foolish to disregard a large body of opinion just because it's anecdotal without a scientific rebuttal.
By all means question everything in brewing.
For me on this topic, this includes questioning whether the scientific research is applicable to the homebrew scale as it is to the professional brewer.

Anyway, to the point, I found a very informative article my Martin Brungard (well researched, citing scientific papers from C Bamforth etc) in the May/June 2019 edition of Zymurgy called "Advances in wort boiling". Unfortunately, as it's a subscription magazine it's not appropriate to post here, but they do have a 7 day free trial, so I would encourage anyone interested in more understanding behind the topic to take out a trial (free for 7 days, that's what I did) subscription and read the article

It makes some very interesting points, and has scientific data to back it up, rather than relying on heresay or tradition. I'll try to summarise the points I found interesting and pertinent to this debate:

"A long hard boil creates thiobarbituric acid (TBA), an oxidant that has been proven to accelerate beer staling". I'd never heard of TBA before and interesting to hear about. I've read many things about boiling hard introducing "heat stress" to the wort, without anything actually explaining what it was or why it was bad. TBA provides the information behind it. There is a danger to overboiling your wort.

Commercial guidance for boiloff (evaporation) rate varies, but generally 3-7% from a random selection of internet pages (Crisps say at least 6% evaporation for an hour, O'Rourke says 4-12%). ... A quick search on the forums has people saying/recommending a boil-off of 10-15% with some brewers stating as high as 20% boiloff.
The article also notes the same - they state pro brewing systems report 2-12% evaporative loss, and 'typical homebrew systems' being 17%. This lends credence to my theory that DMS is less prevalent at the homebrew scale on short boils because the boil is a lot more vigourous.

I have read many many times that "pilsner malt contains more SMM than other malts" so you need to boil it longer. This makes sense, but I'm always wary of statements (without source) saying "it has more" without any quantitative comparison. This article gets its data from Pitz, W.J., Factors Affecting S-Methylmethionine Levels in Malt, Journal of American Society of Brewing Chemists, 1987 and provides a handy graph to display it. I'm reading the values off the graph rather than the raw data, but the important thing is that it has quantitative data. My reading of the graph is that the SMM content for "Typical Pilsner malts" (2.4-4.5 EBC) is in the range of 15-25 mg/kg, whereas pale malts (5-8 EBC) are in the range 3-9 mg/kg (is this the same as ppm, or is ppm based on molarity and not weight?). Roughly this equates to pilsner malt having 5x as much SMM as pale malt. Compounding on this, 2-row barley has less SMM than 6-row barley (6-row has roughly 50% more SMM than 2-row). 6-row seems to be common in American brewing, whereas 2-row is more common in the UK. I don't know what you get in Australia. It also provides graphs for (presumably 6-row) that typical values for the start of the boil is 1000µg/l, whereas pale malt is 300µg/l. Given that the half-life for SMM conversion is 37minutes, this 30% reduction in the starting levels of SMM in pale vs pilsner malt equates (in my opinion) to the reduction you would get in a roughly 60 minute boil.

DMS is pretty much a non-issue with modern malts having negligible levels of SMM. I could guarantee you would never be able to tell the difference between a beer boiled for 15 mins vs 60 mins.
I think the above goes a long way to giving a possible explanation of why some people are certain that you can't taste DMS on a 30 minute boil. Other people haven't stated their recipes here, but if they are using pale malt from 2-row barley, then the initial levels of SMM may be sufficiently low to achieve the required level of conversion/boiloff in a 30 minute boil, whereas others may insist they can taste it because they are using pilsner/lager malt from 6-row barley... and all the shades of grey in between.

It then further goes on to say that SMM to DMS conversion doesn't require a strong boil (it's a function of temperature and time, so a gentle simmer is necessary) and that DMS boiloff can be achieved in 30 minutes after SMM conversion, even for high pilsner malts.

look at the half life of smm as researched by Wilson & Booer. Inbev are brewing beer for millions of tasters.
He directly references Wilson and Booer here. DMS is driven off relatively quickly, but it continuously produced whilst there is appreciable levels of SMM in the wort.

There are some good graphs that show levels of SMM and DMS in the wort for Pale and Pilsner malts during a 60 minute boil. They are fascinating and very open to interpretation, so rather than me trying to interpret it and get shouted at from both sides, I suggest you read the article and come to your own conclusions. It also has the on the graphs the level of when DMS is objectionable in beers (100 microgram/l, if anyone is interested, although you can notice it as low as 30).


Yet in 2022, the best educated brewers at the breweries with the most to gain financially from shortening the boil, aren't. They are investing money and time in developing brewing systems that shave degrees of boil temperature.
The majority of the beer brewed/consumed on the commercial scale is lager, and thus I am guessing the majority of research is targeted towards lager. As lager/pilsner malts have a higher level on SMM than pale malts, this may go a way to explaining why they have longer boils than homebrewers brewing with pale (not pilsner) can achieve.

I would like to see some scientific evidence of why a shorter boil would be OK. What I have read is that 80 minutes is the sweet spot.
I think this article could be what you are looking for 😉 (that a shorter boil (in some circumstances) is OK). It goes into a bit of detail and states that isomerised alpha acids degrade after about 60-80 minutes in the boil and bitterness is actually reduced from this point on. He recommends a maximum of 70 minutes.

There are some good recommendations at the end (I'm not advocating any of them, don't have a go at me, read the article if you are interested). He suggests that a gentle simmer for the first 30 minutes is good, followed by an uncovered boil to drive off DMS. For higher kilned malts like pale, or vienna/munich, the initial simmer may not be necessary (see stuff above about reduced levels of SMM inherent in the grist)!

He also goes into a bit of detail about why wort circulation is more important than boil vigour to drive off DMS via contact with the atmosphere. Pro brewers have pumps/fancy gadgets to forcibly recirculate the wort, but for a lot of homebrewers (in my opinion) the only way to achieve wort circulation is via a rolling boil.
I have a feeling that homebrewers have read 'vigourous' and been boiling at unnecessarily high rates because that's what the research has said.
Again, the 'vigourous/rolling' boil is something that gets stated time and time again without any quantitative measurement of what 'vigourous' or 'rolling' actually means, and why it is necessary. This provides at least some quantitative measurement. He states that the wort speed across the surface of the kettle (during a rolling boil) should be at least an inch per second (no guidance on a recommended speed or upper limit), but having seen many many video of homebrew boils, they are far in excess of this. I think that a lot of homebrewers are boiling unnecessarily hard.

Unfortunately, he doesn't go into a lot of detail about colloidal stability, haze and head retention (if those are important to you!). Boiling "too long and hard" reduces coagulable nitrogen which damages a beer's head retention properties - but doesn't go into details of what "too long" and "too hard" are unfortunately.

Anyway, I found it fascinating (and well researched) and it fills in the gap between the scientific evidence that you should boil for at least 60 minutes, and why so many people can't detect any DMS off flavours with a reduced boil on the homebrew scale on their equipment and their recipes. I would encourage people to read the article and form your own opinions, then brew beer you like!
 
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Agentgonzo

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Worth repeating. There's a lot going on, and whilst money and time shouldn't be ignored, they should be low in priority in order to make the best beer possible.
There are hundreds of things I know I can do to make "the best beer possible". This includes things like fermentation fridge, water-treatment plant, live yeast, keg/conditioning cellar, beer fridge, tap dispensary. Unfortunately for me, I don't have a dedicated brewing space and have to use the utility room and don't have space for a dedicated kegerator, so put bottles in the garage and then a few in the fridge before drinking. To get the best beer possible, I'd need to buy a lot of equipment that I don't have space to store, which would necessitate building an extension. I don't have that kind of money.

As with all things, it's a balance and up to each person to decide where that balance lies for them. I'm willing to accept slightly-less-perfect beer as a tradeoff for a much simpler and cheaper setup. Whilst on some things I can justify spending more for a better beer, I'm not rich enough for money to be a low priority for large ticket items.
 
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Sadfield

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There are hundreds of things I know I can do to make "the best beer possible". This includes things like fermentation fridge, water-treatment plant, live yeast, keg/conditioning cellar, beer fridge, tap dispensary. Unfortunately for me, I don't have a dedicated brewing space and have to use the utility room and don't have space for a dedicated kegerator, so put bottles in the garage and then a few in the fridge before drinking. To get the best beer possible, I'd need to buy a lot of equipment that I don't have space to store, which would necessitate building an extension. I don't have that kind of money.

As with all things, it's a balance and up to each person to decide where that balance lies for them. I'm willing to accept slightly-less-perfect beer as a tradeoff for a much simpler and cheaper setup. Whilst on some things I can justify spending more for a better beer, I'm not rich enough for money to be a low priority for large ticket items.
I was specifically talking about the boil process, time and cost, regardless of system you use.

I certainly don't think there's any correlation between equipment value and beer quality. Sometimes, all the gear and no idea, can be applicable.

I know two brewers that used plastic pico boilers, one won the national homebrew competition and the other the Brewuk(?) comp that led to him having his Vienna IPA brewed at Thornbridge and sold in Waitrose.
 
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foxy

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This thread has made me learn far more about the chemistry of the boil than I ever thought I would be interested in!

I don't dispute any of the research into boil times and DMS, but I couldn't explain the dichotomy between the research saying that you need the 60 minute boil, and the significant number of homebrewers (here and elsewhere) saying they can't tell the difference/can't taste DMS on short boils. I think it is foolish to disregard a large body of opinion just because it's anecdotal without a scientific rebuttal.

For me on this topic, this includes questioning whether the scientific research is applicable to the homebrew scale as it is to the professional brewer.

Anyway, to the point, I found a very informative article my Martin Brungard (well researched, citing scientific papers from C Bamforth etc) in the May/June 2019 edition of Zymurgy called "Advances in wort boiling". Unfortunately, as it's a subscription magazine it's not appropriate to post here, but they do have a 7 day free trial, so I would encourage anyone interested in more understanding behind the topic to take out a trial (free for 7 days, that's what I did) subscription and read the article

It makes some very interesting points, and has scientific data to back it up, rather than relying on heresay or tradition. I'll try to summarise the points I found interesting and pertinent to this debate:

"A long hard boil creates thiobarbituric acid (TBA), an oxidant that has been proven to accelerate beer staling". I'd never heard of TBA before and interesting to hear about. I've read many things about boiling hard introducing "heat stress" to the wort, without anything actually explaining what it was or why it was bad. TBA provides the information behind it. There is a danger to overboiling your wort.


The article also notes the same - they state pro brewing systems report 2-12% evaporative loss, and 'typical homebrew systems' being 17%. This lends credence to my theory that DMS is less prevalent at the homebrew scale on short boils because the boil is a lot more vigourous.

I have read many many times that "pilsner malt contains more SMM than other malts" so you need to boil it longer. This makes sense, but I'm always wary of statements (without source) saying "it has more" without any quantitative comparison. This article gets its data from Pitz, W.J., Factors Affecting S-Methylmethionine Levels in Malt, Journal of American Society of Brewing Chemists, 1987 and provides a handy graph to display it. I'm reading the values off the graph rather than the raw data, but the important thing is that it has quantitative data. My reading of the graph is that the SMM content for "Typical Pilsner malts" (2.4-4.5 EBC) is in the range of 15-25 mg/kg, whereas pale malts (5-8 EBC) are in the range 3-9 mg/kg (is this the same as ppm, or is ppm based on molarity and not weight?). Roughly this equates to pilsner malt having 5x as much SMM as pale malt. Compounding on this, 2-row barley has less SMM than 6-row barley (6-row has roughly 50% more SMM than 2-row). 6-row seems to be common in American brewing, whereas 2-row is more common in the UK. I don't know what you get in Australia. It also provides graphs for (presumably 6-row) that typical values for the start of the boil is 1000µg/l, whereas pale malt is 300µg/l. Given that the half-life for SMM conversion is 37minutes, this 30% reduction in the starting levels of SMM in pale vs pilsner malt equates (in my opinion) to the reduction you would get in a roughly 60 minute boil.


I think the above goes a long way to giving a possible explanation of why some people are certain that you can't taste DMS on a 30 minute boil. Other people haven't stated their recipes here, but if they are using pale malt from 2-row barley, then the initial levels of SMM may be sufficiently low to achieve the required level of conversion/boiloff in a 30 minute boil, whereas others may insist they can taste it because they are using pilsner/lager malt from 6-row barley... and all the shades of grey in between.

It then further goes on to say that SMM to DMS conversion doesn't require a strong boil (it's a function of temperature and time, so a gentle simmer is necessary) and that DMS boiloff can be achieved in 30 minutes after SMM conversion, even for high pilsner malts.


He directly references Wilson and Booer here. DMS is driven off relatively quickly, but it continuously produced whilst there is appreciable levels of SMM in the wort.

There are some good graphs that show levels of SMM and DMS in the wort for Pale and Pilsner malts during a 60 minute boil. They are fascinating and very open to interpretation, so rather than me trying to interpret it and get shouted at from both sides, I suggest you read the article and come to your own conclusions. It also has the on the graphs the level of when DMS is objectionable in beers (100 microgram/l, if anyone is interested, although you can notice it as low as 30).



The majority of the beer brewed/consumed on the commercial scale is lager, and thus I am guessing the majority of research is targeted towards lager. As lager/pilsner malts have a higher level on SMM than pale malts, this may go a way to explaining why they have longer boils than homebrewers brewing with pale (not pilsner) can achieve.


I think this article could be what you are looking for 😉 (that a shorter boil (in some circumstances) is OK). It goes into a bit of detail and states that isomerised alpha acids degrade after about 60-80 minutes in the boil and bitterness is actually reduced from this point on. He recommends a maximum of 70 minutes.

There are some good recommendations at the end (I'm not advocating any of them, don't have a go at me, read the article if you are interested). He suggests that a gentle simmer for the first 30 minutes is good, followed by an uncovered boil to drive off DMS. For higher kilned malts like pale, or vienna/munich, the initial simmer may not be necessary (see stuff above about reduced levels of SMM inherent in the grist)!

He also goes into a bit of detail about why wort circulation is more important than boil vigour to drive off DMS via contact with the atmosphere. Pro brewers have pumps/fancy gadgets to forcibly recirculate the wort, but for a lot of homebrewers (in my opinion) the only way to achieve wort circulation is via a rolling boil.

Again, the 'vigourous/rolling' boil is something that gets stated time and time again without any quantitative measurement of what 'vigourous' or 'rolling' actually means, and why it is necessary. This provides at least some quantitative measurement. He states that the wort speed across the surface of the kettle (during a rolling boil) should be at least an inch per second (no guidance on a recommended speed or upper limit), but having seen many many video of homebrew boils, they are far in excess of this. I think that a lot of homebrewers are boiling unnecessarily hard.

Unfortunately, he doesn't go into a lot of detail about colloidal stability, haze and head retention (if those are important to you!). Boiling "too long and hard" reduces coagulable nitrogen which damages a beer's head retention properties - but doesn't go into details of what "too long" and "too hard" are unfortunately.

Anyway, I found it fascinating (and well researched) and it fills in the gap between the scientific evidence that you should boil for at least 60 minutes, and why so many people can't detect any DMS off flavours with a reduced boil on the homebrew scale on their equipment and their recipes. I would encourage people to read the article and form your own opinions, then brew beer you like!

You seem to be thinking boiling is just about DMS, it isn't. DMS is never fully removed from beer/lager and in both the threshold contributes to the flavour of both.
DMS is still being removed during fermentation. Boiling is also about coagulation and precipitation of the proteins which really is vital otherwise the proteins negatively affect the clarity head and foam stability. I have mentioned before 80 minutes is the sweet spot for a boil time, while 60 minutes is fine.
As for the boil, it is the heat and the violent movement of the wort which causes the coagulation and precipitation of the proteins.

The recirculating of the boiling wort is generally used by the larger breweries is called a calandria where they are boiling 1,000's of litres not necessary for the home brewer.
The Oxford Companion to Beer Definition of calandria,

I agree with Agentgonzo. Make a beer you like, but more importantly, make it well.

Taking up any hobby, sport or work practice it always pays dividends to try and produce the best outcome possible and keep trying. I understand that a lot of those on this forum are retired or aged but for those I would say take a leaf out of Gandhi's book.
'Live like you are going to die tomorrow and learn like you are going to live forever'
Also those who are wanting to learn, a good blogger to follow is Scott Janish, he does all the research, so no coming up against pay walls or searching through Wiley online library. What he writes he backs up with where the information came from.
 
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Agentgonzo

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You seem to be thinking boiling is just about DMS, it isn't
You seem to know what everyone else thinks more than they do!

I know it's not only about DMS. The article just spent a lot more time talking about DMS than other things.

Boiling is also about coagulation and precipitation of the proteins
we know. You keep mentioning it. So did I:
Unfortunately, he doesn't go into a lot of detail about colloidal stability, haze and head retention (if those are important to you!).
 

foxy

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Agentgonzo said, Unfortunately, he doesn't go into a lot of detail about colloidal stability, haze and head retention (if those are important to you!).
Well it is important, as with anything it is the first impressions that count. The first sip of any beer is visual. If it doesn't look the goods it generally isn't.
 

Cheyne_brewer

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Just read my eltrickery meter at the start and end of the boil using my Hopcat 45l. Total usage 4kWh, at 38p/kWh that makes £1.52 - way less than a half of badly kept ale in my local. Well pleased 😀. 25l of “Master Batemans DM” for the summer 🥳.
 

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