How important is it to leave lid off during boiling?

[MaxPower49]

Made my first batch last week and it is still in the primary now. I’m reading How to Brew now and I just saw where he recommends to leave the lid off during boiling to let some things escape and avoid off flavors. How important is this? I left the lid on or slightly cracked most of the time mainly because my stove had a hard time to keep a rolling boil with the lid off. Is my beer going to taste funny?

 

[MrShake]

Assuming you used extract and not all-grain, you will be fine!! the DMS that people worry about has already been boiled off during the manufacture of the extract.

 

[Kilgore_Trout]

Assuming you used extract and not all-grain, you will be fine!! the DMS that people worry about has already been boiled off during the manufacture of the extract.

Not entirely true. DMS will still be produced as long as it's above 140, although not as much as an all grain batch.

If I'm doing stovetop I leave it covered until I get a good boil and then remove. There's a potential for DMS here but I doubt you'll have problems.

 

[MaxPower49]

Thanks... it is an extract batch so hopefully I'll be ok.