Lid partially off with extract brew?

[laxation]

So I found out yesterday I'm apparently not supposed to boil with the lid on...

But when I boil (mashed potatoes, pasta, anything - not just beer...) I do it with the lit slightly open. I've just always done this to stop the thing overflowing. Slightly - being maybe 10-20% open.

I've already done it with 2 brews so far for a full hour boil (one extract, which is delicious - and one partial, which I just kegged yesterday so I dunno yet, but tastes ok out of the hydrometer tube...)
Also did it with a 20min boil for a dr smurtos, which was also delicious!

So, so far I'm 2.5/3 for the beers being good, but have I just been lucky? Can you even get DMS in extract?
Is the lid slightly off enough to avoid it?

Doing it with the lid partially open is the only way I can get the pot to boil. We have a POS electric stove, and last night I tried the camp stove (could only do a slight boil) and BBQ wok burner (nothing)

I've tried googling it and found every single different answer under the sun, so if anyone has any anecdotal evidence that the lid doesn't really matter, I'm all ears!

If it matters, when doing the boil, I aim for roughly 1.040 amount of DME. The extract I brewed was 1kg DME into 10L water.

 

[earle]

I think this is more of an all grain issue. If you're using extract the compounds that you want to drive off with a boil should have already been driven off during the production of the extract.

 

[Jack of all biers]

My anecdotal experience over 12 years AG is that having the lid partially open will not keep enough DMS in the wort to create tastes in the brew. This includes a lot of lager brews typically more prone to DMS issues.

Now I have a vent on my kettle (too hard to describe using my phone) and the same issue as you with only getting a simmer with the lid off, but over the years I have tweaked it to get a good rolling boil with vent open and lid partially open. I think with extract you should be fine.

 

[laxation]

Cheers guys.

What about a partial mash - should I just avoid them until I get a better set up?

 

[Jack of all biers]

Give it a crack, but from my experience, the extra amount of grain to make a full AG batch is the only difference (other than size of kit) and it'll be the same or more time to do a partial and extract. You shouldn't have any issues with DMS, but if you're unsure, use ale malt for your mash as opposed to pils