90 minute boils v shorter boils

[Sadfield]

The thumbnail link compares a 30 minute and a 90 minute one.
And the colour change is undesirable, no?

The darker one looks more appealing. Entirely subjective, however it does prove that boil time makes a physical difference. I'm not convinced the pitifully small test group in one scenerio in the brulosophy exbeeriment is of any significant value.

 

[foxy]

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. This is for commercial breweries. What is one achieving in the boil is the driving off of DMS, maillard reaction and the condensing of the wort. Every man to his own but I would never consider a boil under 60 minutes.
This question comes up every year. I usually put a link up to Timothy O'Rourkes 'The purpose of the boil' He is a UK Master Brewer but seems COVID has taken its toll the website has been disabled.

 

[foxy]

After my quadruple brewday, it got me thinking how much difference does a 90 minute boil for a stout make verses a shorter boil, same with the standard 60 minute boil and I have seen people mention 30 and even 15 minute boils.

Over multiple batches it adds up to quite a saving if you take it to the extremes, what do you guys think?

If you want to save some time, and time is important, have a look at no sparge brewing. Don't skimp on the processes which are important.

 

[Brewshed]

I always do 60 minute plus boils. To be honest I don't see the value of a shorter boil because it is while the boil is taking place that I am sterilising the fermenter, rehydration yeast etc and a 30 minute boil would not give me enough time to do all that.

 

[Mayor of Simpleton]

When I started out, I would routinely boil for 90 mins. I dropped that to 60 mins a few years ago with no discernible difference. 60 is plenty to drive off any DMS.

 

[DixeySJ]

I think this discussion has come up before, not surprisingly. There doesn't seem to be a definite answer. As already noted, there is an historical trend whereby older recipe books (e.g. GW) routinely ask for 90 minute whereas more recent ones (from my shelf, James Morton springs to mind) are all 60 minute boils. I tend to follow the recipe but I'm not sure I can tell any difference between similar beer styles done with longer or shorter boils. Out of interest, the shortest boil time I did was 30 minutes - that was Dave Heath's recent Mild recipe from his YT channel. Turned out great .... I like the idea of adjusting the '90 minute' recipes to 60 minutes, making any necessary adjustments to the hops to preserve EBU. Might try that next time.

 

[chthon]

W.r.t. DMS, I do think that the Brülosophy experiments have shown that it is not a (big) problem anymore. That was why I did the 30 minute boil tests last year too, it was just with pilsner malt, and I did not get any weird tastes. However, I must say that was for 5 litre, which can be cooled very rapidly. But I tend to lean in the direction that modern malts (or malting techniques) have less DMS precursors.

 

[fgoulding]

And every recipe by DH uses Kveik

I thought he called it Kwake...:tinhat:

 

[CD]

I finished up doing an 80 minute boil, which worked fine.

 

[Wynne]

The objectives of wort boiling are to:

• Stop enzymatic conversion by denaturing malt enzymes.
• Sterilise wort for microbiological stability.
• Extract bitterness from hops through isomerisation of hop alpha-acids.
• Adjust wort colour and flavour through Maillard reactions between amino acids and reducing sugars.
• Improve haze stability by coagulating proteins and forming protein/ carbohydrate/polyphenol complexes for removal.
• If required, concentrate wort through evaporation to achieve required specific gravity.
• Strip undesirable volatiles, such as DMS precursor SMM, through evaporation, to below the flavour threshold (100µg/L).

EBC. (2002). Wort boiling and clarification. In European Brewery Convention (EBC) Manual of Good Practice,Fachtverlag Hans Carl, Nuremburg.

As wort boiling is an energy intensive process, in commercial brewing, the boil is ended as soon as the objectives have been achieved to the extent required for the particular beer being brewed. A shorter boil uses less energy and can shorten the overall brewing process enabling more brews to be completed per day.

A good way to test whether a shorter boil would be sufficient s through side-by-side testing of beer brewed with wort boiled for different lengths of time and comparing key attributes such as aroma, taste, bitterness, colour, clarity, foam retention, specific gravity/abv. It is also possible to test samples of wort taken during the boiling process for some of these attributes.

 

[nickjdavis]

The darker one looks more appealing. Entirely subjective, however it does prove that boil time makes a physical difference. I'm not convinced the pitifully small test group in one scenerio in the brulosophy exbeeriment is of any significant value.

Personally I'm not convinced by any Brulosophy exbeeriment. I dont think I've ever come across an instance where their exbeeriment has ever demonstrated a significant difference in what they are testing.

 

[chthon]

Personally I'm not convinced by any Brulosophy exbeeriment. I dont think I've ever come across an instance where their exbeeriment has ever demonstrated a significant difference in what they are testing.

Only a couple. But their goal is also to check:"what if I do this part of the process in manner Z, versus the age old and cumbersome manner Y". There are many instances where there is indeed no difference, so that they can say "manner Z, which is simpler", does work.

E.g. the Short and Shoddy series started as tests to compare beers brewed the normal way, versus shortening the process through approximate, manual addition of minerals, only no-sparge (sacrificing efficiency), and shorter boils, mostly leading to boil day of appr. 3 hours I think in their case. And still nice results.

So, no significant difference as result of an experiment is also significant.

And then there were a couple of experiments with fermentation vessels of different types and materials, which led to unexplainable significant differences.

 

[Sadfield]

There are many instances where there is indeed no difference

By what metric? Sensory evaluation by less than twenty people? What about the statistical significance of thousands of brewers over hundreds of years tasting the beers they brew?

Boil time is a classic example, the cost saving from doing short boil is significant, yet brewers still choose to do it based on their own sensory evaluation.

The best that can be said for these exbeeriments is that they are inconclusive.

 

[dmtaylor]

Could you expand on that maybe?

Big reasons for a long boil, but why it's not so important:

1) Hop utilization. But utilization falls off rapidly beyond 60 minutes. If you're concerned about reduced bitterness, it is easy to shorten the boil and just use a couple extra grams of bittering hops.

2) Maillard reactions. But these don't really kick in and become very noticeable until you boil for 3 or 4 hours. Ain't nobody got time for that.

3) DMS reduction. But modern malts are less susceptible to this problem, especially on the homebrew scale and when not applying a lid to your kettle. Most homebrewers don't put a lid on it. If you do... don't. Easy fix.

You can make award winning recipes without boiling longer than 60 minutes. And heck, I would guess the same is true for 30-45 minutes -- I want to experiment more with this.

In the end, you don't need to believe me, or anyone else. Experiment for yourself, and figure out your own version of the truth. Don't believe anyone's word as gospel. Figure it out.

 

[AJA]

I do agree that they should change their null hypothesis up. I.e. instead of just failing to prove there is a statistical difference between two variables, instead trying to prove that there is no difference between the beers. This would obviously need a larger sample size.

Their approach in general is admirable though, and is a useful reference in the case of asking 'do I actually need to do this'?

In terms of boil length, they do have a podcast on this, which is very boring but links to the paper:
Wort Boil Time and Trub Effects on Fermentability
https://www.tandfonline.com/doi/abs...treatments, the,°C under atmospheric pressure.

Basically, what they found is what homebrewers in general have observed, longer boils = slightly less fermentability. But obviously shorter boils = more DMS, whether in modern processes that is ever going to be over the taste threshold depends on the beer you are brewing etc.

Perhaps we should play around and see what difference it makes. I do split boils anyway so happy to have a go myself :)

 

[AJA]

Oh, they explained the fermentability point a bit further. Being a chemist by education, this interested me the most.

Boiling longer leads to a reduction in free amino nitrogens, due to reactions with sugars. This is not a problem until they reach a certain threshold (300ppm?), below this fermentation slows and finishes at higher FG.

 

[Sadfield]

The above posts from @AJA and @dmtaylor pretty much cover it.
There's well researched science behind brewing, and these things do make a difference. Whether as an individual you can detect or perceive those differences is what you need to explore for yourself.

It's worth remembering that we use all our senses when enjoying beer. Blind taste tests become redundant if you perceive a beer to be maltier because its a couple of SRM darker, or aromatically hoppier due to those extra bitterness units.

 

[dmtaylor]

Blind tests become most useful to me when *I* am the one doing the blind tasting.

I could give you my thoughts on Brulosophy, but, we really digress...

 

[MrRook]

In the end, you don't need to believe me, or anyone else. Experiment for yourself, and figure out your own version of the truth. Don't believe anyone's word as gospel. Figure it out.

What he said. See what gives you results that you are happy with. For a long time I did 45 minute mashes and boils with no noticeable difference compared to 60 minutes (never did 90). I did a BIAB pilsner yesterday with a 40 minute mash and a 30 minute boil. I'll see if that works for me.

 

[crescent city Mike]

I usually boil for 90 minutes but, depending on several factors, I'll boil for 75 minutes. Just to throw a little chaos into this, read about a study done some years ago.
https://crescentcitybrewtalk.com/wort-boiling/