Boiling - Lid On Or Lid Off

[BrewDaddy]

Hi - I've done a bit of research and the general consensus seems to be to do the boil with the boil pots lid off (to prevent DMS).

However, I've also read a few things that suggest this is only relevant in all grain brewing.

Curious to know peoples thoughts on lid on vs lid off for extract brewing (especially for partial (10 litre) boils)

edit: change DME to DMS (thanks Yob)

 

[Yob]

Assume you mean DMS?

Always lid off, easier to control the boil, if you leave the lid on be prepared for a sticky cleanup

 

[BrewDaddy]

Assume you mean DMS?

Always lid off, easier to control the boil, if you leave the lid on be prepared for a sticky cleanup

Yes, I did mean DMS (damn acronyms)

Boil overs aside (I stuggle to get 10 litres to a vigorous boil on my stove, and I have a 20 litre pot, so I have plenty of spare space), has anyone experienced DMS flavours with lid on boils using extract???

 

[Barge]

Boiled an extract brew with the lid partially on (to keep a decent rolling boil).

It is the only batch that I have ever brewed that has had DMS. The batch was undrinkable.

Definitely LID OFF!!!

 

[Yob]

The manufacturer has, I would assume already boiled the arse out of it to get it as either tinned Liquid Extract or Dry Extract.

AFAIK DMS should not be an issue for extract.

Happy to be proven wrong on this but that is my understanding.

What was the taste like Barge? are you sure there wasnt something else going on?

Yob

 

[Baulko Brewer]

Thirsty boy gave me some advice that may help.

I float an alfoil pie tin on the surface of the wort as its boiling, it drastically reduces heat loss at the liquid surface and increases boil vigor.

 

[wbosher]

I heard it was ok to leave the lid on to bring up to boiling point, then take it off?

 

[JDW81]

I heard it was ok to leave the lid on to bring up to boiling point, then take it off?

That is ok, you just need to keep an eye on it so it doesn't boil over and make a big sticky mess.

I fire up my burner as soon as my first runnings hit the kettle so it is practically boiling by the time I have finished my sparge, no need to put the lid on at all (not really an option for extract or BIAB though).

 

[Barge]

At first I wasn't sure what the taste was. I researched off-flavours and found that DMS tastes like cooked corn. At the time I had some XXXX Gold on hand so I cracked a stubby and added the juice from a tin of corn kernels to it. The beers tasted identical. I'm not sure what the chemistry involved is as I have never bothered to research further (I have a degree in chemistry BTW) but as I haven't boiled like this before or after, the empirical evidence suggests that boiling extract brews covered can lead to DMS.
The beer in question was a Heineken type clone. ie basic malt flavour, very little hop flavour, no esters, diacetyl etc so the flaw was glaringly obvious.

FWIW, my remedy was to mix the homebrew with the XXXX gold to dilute the DMS past the taste threshold. It worked but the batch was obviously very ordinary (if it could be helped by XXXX gold).

Anyhow, I would be interested to hear other experiences. I have brewed all types of beers, from extract-only to all-grain but that's my one and only experience with DMS.

Cheers