Brewing Outside and kamikaze flies

[Baldylocks Brewery]

Boiling with the lid partly on does not itself reduce the amount of steam; but it means you need slightly less power to maintain the boil, and that does.
If your extractor can’t keep up then you might like to look at the steam condenser setup that @chopps has done on his larger scale setup… essentially a cover that routes the steam into a downwards pipe with a bit of cold water spraying into it. The spray condenses the steam and it just drips into a bucket. Very neat.

It’s mentioned in this episode of his brewery build video (which is very much worth watching in its own right):

Wow very interesting video and will be watching more in the series. thanks TETB

 

[Baldylocks Brewery]

If your extractor can't handle the steam, you may be boiling unnecessarily strongly. Advice is for a "rolling boil", not a volcano! Recommendations for breweries are to boil off 4-10% of the wort volume. Depending on your kettle, this may be more of a gentle boil than whacking your stove/element onto full, whilst still strong though to drive off the necessary amount of DMS (unpleasant volatile flavours), extract the goodness from the hops and coagulate the proteins so that your beer becomes clean.

Having seen some of the HUGE boilers and boiloff rates some people on the internet use, I think they have been told a "vigorous/rolling" boil and went overboard.

Of course, if one of your objectives is to drive off extra water to concentrate the wort for a stronger beer, then you'll need a monstrous boil (or just a longer one)!

Thanks Agent, I'm only using a 3KW element in a 56L pot so it doesn't give what I would consider as vigorous boil (not 100% sure what that looks like though) but I suppose the size of the pot adds to the evaporation.

 

[Agentgonzo]

That's probably about the right power for 56l then. I guessed a smaller pot size of you were in your kitchen (I assumed from the cooker hood)

 

[MikeB.]

Well it worked, and didn’t experience any boil over either.

 

[obscure]

Well I shall be adding 'using a lid on my boiler' to the long list of practices that I'm going to continue to do, despite seeing dire warnings to the contrary!

'The stuff that condenses' is just your wort, after all (mostly water), and it's condensing all the time when you're boiling any liquid.

I am extremely tempted to try this on my next batch I‘ve always brewed with the lid off as this is just what I assume you are supposed to do but potential reduction in energy aside not having to deal with huge amounts of steam would be a huge plus. Worst case it gives poor results and I go back to the normal way.