Boil - with lid or not?

[DipenK]

a quick question about the boil process- do you leave the lid on or keep it off? I am using a peco boiler.

I know it will make a difference to the boil off rate and i'd have to add more water pre boil to compensate, but is there any other difference? someone mentioned some chemicals that are released as part of the boil but I cant find where that was.

Obviously there is also a risk of things falling into the kettle if the lid is off (i brew outside as the family don't like the smell!!)

Thanks,

DipenK

 

[Dexter101]

I believe general consensus is you shouldn't have the lid fully on as there are substances that are removed via the steam.

Some people will put the lid on to bring up to boil and then remove or only partially have it covered.

Personally I don't use a lid at all but I have a small boil on the hob.

 

[marshbrewer]

The substance you are referring to is probably DMS, I believe, which is driven off during the boil. I also brew outside, and have the lid on until I get a vigorous boil, then off for the rest of the boil, apart from the last 15 mins when it goes back on loosely to sanitise it so I can have it on during cooling without worrying that it will drop any unsanitised nasties in the wort.

 

[Sadfield]

Lid off.

There's substance in grain (SMM) that degrades to DMS at temperatures above 80°c. In all but the palest of grains this removed during the malting process. In wort made using pale malt SMM will convert to DMS above 80°C and needs volatilising through vigorous boiling. This can take over 90 minutes to be completely removed. What ever your boil time, the best practice is to boil vigorously and keep the kettle uncovered at temperatures above 80°C, otherwise the steam and DMS will condense and drip back into your wort.

 

[Duxuk]

I've read the science but still boil lid on. Some malt my produce DMS precursors but Maris Otter, my base malt of choice, won't. It's not broke so I won't try to fix it.

 

[peebee]

Lid off. Is there a choice?

DMS? Who cares. Wort all over the floor? Do care!

I wonder about people who boil with the lid on. Are they using a boiler? Or are they using a paint tin with a candle?

 

[Duxuk]

Lid off. Is there a choice?

DMS? Who cares. Wort all over the floor? Do care!

I wonder about people who boil with the lid on. Are they using a boiler? Or are they using a paint tin with a candle?

At the risk of sounding like Delia Smith I use the AGA. The hotplate is exactly the same diameter as my 32l stockpot. I shuffle it to the edge once it's up to temp.

 

[Grealish]

At the risk of sounding like Delia Smith I use the AGA. The hotplate is exactly the same diameter as my 32l stockpot. I shuffle it to the edge once it's up to temp.

I can't get mine to boil on the Aga because the bottom isn't flat enough. What make is yours?

 

[Tom Freeman]

Brulosophy to the rescue!

http://brulosophy.com/2016/10/31/the-boil-lid-on-vs-lid-off-exbeeriment-results/

 

[Dexter101]

Brulosophy to the rescue!

http://brulosophy.com/2016/10/31/the-boil-lid-on-vs-lid-off-exbeeriment-results/

Wonder what would happen if you pressure cooked the boil...

 

[Drunkula]

Brulosophy to the rescue!

http://brulosophy.com/2016/10/31/the-boil-lid-on-vs-lid-off-exbeeriment-results/

This! If you can't get to a boil without lid off and you're not using some bohemian fancy-boi grains then teeter that lid and sit on it if you have to.

Modern modified grains mean a lot less chances of DMS so until you've got a problems assume there isn't one.

 

[Sadfield]

Brulosophy to the rescue!

http://brulosophy.com/2016/10/31/the-boil-lid-on-vs-lid-off-exbeeriment-results/

"I’ll continue with my standard practice of boiling without a lid, though my confidence in contained brewing systems has admittedly increased. If anything, it’s results like these that lead me to question the accuracy of beer evaluation."

So, 8 out of 20 detected the difference, but the author admits that from other experiments some people struggle detecting even high levels of DMS. Meaning, 12 tasters may not have detected DMS that was there.

I agree that, if no one else is drinking your beer and you don't detect DMS, then lid on or lid off is irrelevant.

This experiment doesn't prove that a beer boiled with the lid on is free from DMS. Quite the opposite.

 

[foxy]

I also will continue to vent the steam from the boil, there is also a consideration to the hops, though not a great contributor of DMS it still comes into the equation, as does dry hopping which will contribute more. It all adds up. As for the Brulosophy, every hit on that blog turns into money, the more controversial the blog the more hits and the more coin earned.

 

[Cwrw666]

Lid off, if only to avoid boilovers.
BTW you can top up with boiling water from a kettle at any point during the boil and even afterwards.

 

[Duxuk]

I can't get mine to boil on the Aga because the bottom isn't flat enough. What make is yours?

The AGA hotplate is flat so I assume you mean the make of pan? I don't know. It is stainless and cost about 50 quid on Ebay.

 

[DavidDetroit]

I boil with a lid on but about an inch of space to let whatever escape.
Thinking about it, there are actions I take that may or may not affect the beer quality; however, since I'm happy with how my beer turns out, I don't change them.

 

[dwhite60]

Brulosophy to the rescue!

http://brulosophy.com/2016/10/31/the-boil-lid-on-vs-lid-off-exbeeriment-results/

That was quite interesting. DMS doesn't seem to be the problem once thought. Perhaps due to changes in grain being grown to produce less DMS precursors?

Pot with the lid had to run a slightly higher temp because of increased pressure from the lid. Perhaps the slightly higher heat either broke it down or got more into the steam that escaped? Like someone else said, a pressure cooker boil would be interesting.

All the Best,
D. White

 

[foxy]

Like someone else said, a pressure cooker boil would be interesting.

All the Best,
D. White

I was hoping he was joking.

 

[Dexter101]

I was hoping he was joking.

It was light hearted curiosity but I was hoping someone would explain why it would be a bad or good idea.

 

[Grealish]

The AGA hotplate is flat so I assume you mean the make of pan? I don't know. It is stainless and cost about 50 quid on Ebay.

The Aga hot plate needs a pot with a perfectly flat base to work properly. I got one from Wilko that was supposed to be suitable but wasn’t, it had a very slight ‘rock’. You obviously got luckier than me.