Questions about DMS

What are the main causes of DMS? I have also been told of issues with leaving the lid on the wort (while boiling) been contributing to it. Last night my budy and I did two batches of Irish Red Ale and left the lid on the wort. How much of an effect would this have?

i am only on my 3rd batch so take my reply with a grain of salt... but i have read on here that leaving the lid on during a boil is one main cause of dms. However, if your using extract (as i am as a new brewer) this has been (supposedly) taken care of in the malting process. You can have the lid on to bring your water to a boil, but once the malt has been added i would not use the lid any more.

Continue with your process and let it sit, be patient with your primary fermentation and your time in the bottle and it will turn out ok. Just understand next time that your beer can be better if you leave the lid off. Hope it turns out great.

Cheers!

In all-grain brewing, wort made with pilsner malt is usually given a 90 minute boil to get rid of DMS.
The higher kiln temps used for pale and pale ale malts destroy the DMS precursors.
Also, rapid chilling to 80F or below helps to prevent DMS.

But LME and DME have already been through the process, so I don't think it's as big a problem for extract brewing.

also, if you're having trouble getting a rolling boil (electric stove or the like), you can keep the lid half on to keep that steam and higher vapor pressure on the wort. met a guy at the LHBS that does that on his electric stove - says it works fine.

Awesome thanks for the input guys