60 min vs 90 min boils

[Weizenberg]

What exactly is "thermal stress", and what happens (from a chemistry point of view) that affects the beer?

Have a look at this paper

 

[Agentgonzo]

Have a look at this paper

I was after a couple of sentences of summary that the layman could understand , but I'll take a read. Thanks

 

[The Baron]

Hi I have not read up on thermal stress yet but am I on the right track of limiting the power to give a more gentle boil rather than a vigorous rolling boil because thats what I have done for years I do not let it boil too vigorously and do not use full power, it also limits the boil off amount too.
Please correct me if I am on the wrong track

 

[Agentgonzo]

I think you'll get a selection of different advice. Some insist you need a strong vigorous* boil, whist other people/papers etc say you should limit thermal stress.

I'm of the opinion that if there is conflicting advice, then it probably makes very little practical difference.

Certainly if you haven't noticed any difference/substandard beer, then would do whatever works for you.


*Though I've never had "vigorous" quantified, so your "gentle boil" may be another person's "vigorous boil". A vigorous boil on a 500L commercial system is probably (hard to quantify here, so this is an estimation) the same as a gentle boil on a 30L system

 

[The Baron]

I have judged my boils on the ones I have seen on Youtube etc and would consider mine a gentle roll with surface tension being disturbed but not turning over violently.
I did do vigorous boils years ago but did not see any noticeable difference in my beers so kept the gentler boil since then

 

[buddsy]

I did do vigorous boils years ago but did not see any noticeable difference in my beers so kept the gentler boil since then

Hi I started with gentle boils but my boil off wasn't as much as brewfather estimated.

I have since upped to a stronger rolling boil and have the expected boil off. I guess its laziness on my part and perhaps I should have adjusted the boil off value rate in brewfather?

buddsy

 

[Agentgonzo]

Hi I started with gentle boils but my boil off wasn't as much as brewfather estimated.

I have since upped to a stronger rolling boil and have the expected boil off. I guess its laziness on my part and perhaps I should have adjusted the boil off value rate in brewfather?

buddsy

Swings and roundabouts. If you adjust the value in brewfather, it will compensate by getting you to use slightly less sparge/mash water, which extract slightly less sugar and lead to a slightly reduced efficiency and a slightly lower OG wort. I would put money on the fact you wouldn't be able to tell the difference, but you can compensate for this by adjusting your efficiency/adding a little bit more malt to the mash. I don't know what's more expensive - the extra malt or the extra electricity.

 

[Weizenberg]

I was after a couple of sentences of summary that the layman could understand , but I'll take a read. Thanks

Thermal load involves maillard reactions and its intermediaries. These Maillard intermediates can then further react during beer ageing towards flavour active compounds that affect the flavour stability of beer.

As mentioned earlier, a TBI (AKA TBA) < 45 is considered desirable.

Whatever the individual preferences, thermal load has a noticeable effect on flavour -- which is how I understood the question in this thread.

 

[Weizenberg]

Hi I have not read up on thermal stress yet but am I on the right track of limiting the power to give a more gentle boil rather than a vigorous rolling boil because thats what I have done for years I do not let it boil too vigorously and do not use full power, it also limits the boil off amount too.
Please correct me if I am on the wrong track

The tricky bit is that you need to balance evaporation of unwanted compounds and protein coagulation vs thermal load.

Too low a boil isn't that desirable either. Have a look at the steinecker krones datasheet I posted earlier. It shows temperature ranges for various concerns during boil.

Often, stromboli boilers are used like this:

• 10-15 mins intense boil where temps are in the range of 130-140C.
• 30-40 minute pause.
• 10-15 min further intense boil.

Thats rather high temps during the intense boil, although not at the wort overall since it is recirculated (have a look at the design).

For my homebrew setup, I've settled for 101C in the intense phase (lid on), 99C during the rest (lid on), then 101C for the last, flameout, phase (lid off).

It may not work for everyone, but that's how I dialed it in.

 

[Agentgonzo]

For my homebrew setup, I've settled for 101C in the intense phase (lid on), 99C during the rest (lid on), then 101C for the last, flameout, phase (lid off).

How do you accurately measure this? Most thermometers in use aren't accurate to fractions of a degree (you may have better kit). How do you achieve 101C (ie, above boiling point) - do you use some kind of pressure-retaining setup, or do the additional sugars etc in the wort raise the boiling point over 100C?

 

[The Baron]

I generally boil at 100c to 99c with the lid off and hit my boil off/evaporation.
I do not worry re DMS as I have never had it and nobody has detected it in my beers knowing that some people are more susceptible to it than others so it works for me as is.
Ps I do not do big beers often that need Maillard so to me it is not something I miss and I just get my taste from the malts I use in those styles but I do understand that longer boils and for the words of thickening the beer may add to some styles(like a chef boiling down the juices to impart stronger flavours).

 

[Agentgonzo]

Ps I do not do big beers often that need Maillard so to me it is not something I miss and I just get my taste from the malts I use in those styles but I do understand that longer boils and for the words of thickening the beer may add to some styles(like a chef boiling down the juices to impart stronger flavours).

I'm wondering what the difference in perceptible flavour is if you compare a hard boil (with maillard reactions) vs a gentler boil with a higher proportion of malt, or higher amount of more-roasted grains. I would expect the extra flavour from maillard componds to be slight (but still perceptible), whereas an extra few hundred grams of roasted/crystal/darker malts do make a lot of difference in the final beer.

It would be an interesting brulosophy-style experiment, but I haven't seen anyone do one.

 

[Sadfield]

Whatever the individual preferences, thermal load has a noticeable effect on flavour -- which is how I understood the question in this thread.

100% this.

The amusing thing is that those that reference the Dave Heath video ignore that he talks about altering recipes to try and offset that difference. And repeatedly refers to hoppy beers. Yet it gets extrapolated that boiling longer makes no difference to any style.

 

[Weizenberg]

How do you accurately measure this? Most thermometers in use aren't accurate to fractions of a degree (you may have better kit). How do you achieve 101C (ie, above boiling point) - do you use some kind of pressure-retaining setup, or do the additional sugars etc in the wort raise the boiling point over 100C?

I mostly do Helles and Dunkel, with the occasional Pils and Wheat beer (although I do an ale as well, it's really a mutt between a Munich Dunkel and an Old English Ale. 7.5% ABV, 100% Nelson Sauvignon hops - The Disdsbury Old Ale (DOA) )

The equipment is a calibrated K-thermocouple in a thermowell. Before brewing, I zero calibrate with ice cubes. The controller is a Red Lion PXU.

You can get 101C with the lid on. For lid off, the story is different, but it is SET to 101 for a vigorous boil/movement to evaporate the unwanted. When I ramp to temperature, the lid is always on.

Note that flavour instability is time dependent, especially in this context. So your beer may age differently over 3-4 months or longer. That's probably why none of us really bother with this since our batches never last that long anyways, well... mine don't

Horses for courses.

 

[Polcho]

Well it isn't about, reducing DMS more on the precursor of SMM leading up to the boil. The way science is taking us is towards brewing with none malted grain we wont have to worry about DMS.

How would this be possible.

 

[foxy]

How would this be possible.

From what I have read the SMM comes from the malting process. For a few years now the researchers have been experimenting with unmalted barley. Why? Along with the boil the malting process relies on high energy use. Seems odd that a low cost, high volume commodity attracts ways to reduce energy only explanation is the carbon footprint.
There are a lot of technical papers on the experiments being carried out, but nothing comes without hurdles to overcome.
https://www.mdpi.com/2306-5710/7/1/4/htm
https://onlinelibrary.wiley.com/doi/full/10.1002/jib.319
https://www.researchgate.net/publication/333615282_USING_UNMALTED_BARLEY_FOR_BREWING

 

[Tess Tickle's Brewery]

I have read most of this thread but haven't found any discussion on what I was looking for.

My next beer will be the majority pilsner malt, but I want to try the Floor-Malted type. Not sure if I should step-mash it and/or boil for 60 mins instead of my usual 30. All my best beers to date have had a 30 minute boil and much more flavour.

Has anyone brewed with Floor-Malted malts and boiled for 30 mins?

 

[Davegase]

I have read most of this thread but haven't found any discussion on what I was looking for.

My next beer will be the majority pilsner malt, but I want to try the Floor-Malted type. Not sure if I should step-mash it and/or boil for 60 mins instead of my usual 30. All my best beers to date have had a 30 minute boil and much more flavour.

Has anyone brewed with Floor-Malted malts and boiled for 30 mins?

A lot of brewers will just park in one camp or the other and won't be budged
I would just say experiment and do whatever suits you best. Either way you'll probably get a very good beer
PS have you thought about trying the new Nova lager yeast ?

 

[Tess Tickle's Brewery]

Never heard of it to be fair lol

 

[Davegase]

Never heard of it to be fair lol

I believe it arrived in the UK shortly before Christmas at The malt miller in homebrew sachets.
I've seen several reviews on YouTube and it looks good.
Nova lager yeast