Boil kettle with lid or not

[Ian]

I'm sorry if this one turns out to be a bit of a stupid question, but since I don't know the answer for sure I need to ask it. My kettle is a modified 55L beer keg and I saved the disc cut out of the top and put a slit section of hosepipe around the edge so it can function as a lid to get the boil up quicker and keep it cleaner in between uses. My question is, once I have achieved a rolling boil, do I continue the boil with the lid on or off? I have read somewhere that keeping the lid in place can result in re-condensation of unwanted elements, but I'm a bit hazy on that and I wondered whether boiloff loss was calculated on an open kettle boil or with a lid in place, which logic would suggest would result in less total boiloff.
As a matter of interest, I discover to my chagrin that despite the hose edging, the lid can still fit through the cavity in the top and end up in the wort. I discovered this by accident whilst boiling - say no more!
Cheers,
Ian

[JoKing]

IMHO fly sparging is the laziest way to go. Once you set the inflow / outflow (takes me 5 mins) you just let it go for half an hour, checking on it from time to time. I might post a video some time to show how easy it is. I realise that I have a HLT and pump to make my life easier, but they are still not fully necessary to do fly sparging.

Give it a crack, Ian - you might surprise yourself!

[jt]

I batch sparge, as it requires minimal hands on, attention and / or grey matter
This was the easiest for me to comprehend and put into practice http://bayareamashers.org/content/maindocs/BatchSparging.htm although there is info all over the place

[MrC]

I have the lid on until it boils (watching for boilovers) then lid off for the boil but keep my boil just rolling (not too vigorous) to minimise the amount of boil off whilst still letting the undesirables escape.

The theory is that boiling with the lid off drives off the SMM. SMM is the precursor to DMS, therefore reduced SMM = reduced DMS. More details here...

[Ian]

Cheers for the link Mr Cherry, I actually printed that article out to ponder.

[denimglen]

Lid off the whole way for me.

Batch sparge. (should be) Easiest IMO but haven't tried to fly. Heat some water, dump it in, stir, run off.

Plate chiller? Oooooooooooh get ready to have some fun with that baby ;-)

[Dan]

Regarding keeping the lid off the boil, DMS etc, I like to keep my lid mostly on but tilted so condensation runs off the lid onto the floor, havent tasted any dms that I can detect, it promotes a better boil from my meager 2kw element.
Dont most commercial breweries have covered kettles with chimneys?
I was told DMS was more a problem if the wort is left in the kettle too long after chilling.

[denimglen]

On a similar note...

I always wonder why HB'ers worry about dropping the post-boil wort to ferment temperatures soon as possible to avoid dms (among other things), where some commercial brewers will whirlpool pre-chill and let it sit for like 90 mins at near boiling.

[Mark]

i always thought leaving it hot for ages would kill the late addition aroma hops

[denimglen]

Indeed. I read an article in BYO on Stone and they're adding almost all their hops in the whirlpool.