boiling with lid partially (half) on?

[ekjohns]

So i have been looking for threads on this and there is no real thread talking about the lid being only partially on. I can get a weak boil on my apartment stove on high with my pot wrapped with insulation. However, if i cover 1/4 of the pot with tin foil, i get a rip rolling boil. If I was to do a 90 min boil with 1/4-1/3 of the top of the lid covered to i need to worry about DMS?

 

[cactusgarrett]

You could even cover more than half, and as long as you're getting some venting, the DMS precursors should escape just fine.

 

[wilserbrewer]

If I was to do a 90 min boil with 1/4-1/3 of the top of the lid covered to i need to worry about DMS?

i would doubt DMS would be an issue...try it and find out. You will still likely boil off quite a bit w/ the lid partially covered.

 

[corbomite]

I don't see what it matters. If you boil off DMS it isn't going to be forced back into the liquid state just because there is less area to ventilate through.

 

[ekjohns]

For what I have read it has more to do with the steam (full of DMS) condensing on the lid and falling back into the wort. Ill just make sure to put a paper towel on it to help soak up the condensation

 

[mjohnson]

Yeah, I just tie a dish towel around the lid. Works great. Works great for stuff like chili too - where you want it to thicken a bit.

 

[RiverCityBrewer]

For what I have read it has more to do with the steam (full of DMS) condensing on the lid and falling back into the wort. Ill just make sure to put a paper towel on it to help soak up the condensation

You are correct, and another reason is that if a good portion of the condensate falls back into the kettle, you are essentially not boiling off that volume. This throws off many new brewers who say they aren't hitting their OG and starting volume numbers, first question I ask is if they are boiling with a lid on full or partially covering.

To the OP - In your situation, you will be fine and won't have to worry about DMS, just adjust your recipe and boil time to account for the extra liquid falling back in the pot, or do like you said and just soak it up with a towel.

 

[Cubslover]

I put an over sized lid on it, pulled back an inch to vent, the condensate runs off the side and down the kettle.