Covered boil?

[quiff]

I've just been told that I should not boil the wort with the lid covering the boiler
Is this correct and if so does anybody know why?

[Deebee]

I understand it it to allow the undersireable tanins etc out during the boil.

I always boil with the lid on to spead things up but as soon as the boil is on i drop take the lid off.

Thats about all i know anyway

[OldSpeckledBadger]

There's a chemical called Demethyl Sulphide (DMS) which is driven off during the boil. It has a rather unpleasant cabbage smell and taste. If you like your beer tasting of cabbages then boiling with lid on is the thing to do. Most of us however don't like our beer tasting of cabbages so we boil with the lid off.

[mysterio]

Yeah it's disgusting. If you've ever made a starter from spraymalt extract, boiled it for 10 minutes then cooled it with the lid on you'll have smelt it.

[quiff]

Oh fantastic!!!!
I never noticed any dubious taste when I had a sneaky sample and the lid wasn't on ALL of the boil just about 3/4 of it and even then there was a small vent. Do you think I might be okay?

[Hawkinspm]

If you had a vent and only did 3/4 of the boil I think you may be ok, I did a few brews with a vented lid when I first started and never had this problem - I figured the steam was still escaping with the nasties due to the vent, just not as quickly... Now I take the lid off as soon as the boil starts to be 100% sure though...

[CJBrew]

I have been thinking for a while of the possibility of using a tumble drier vent tube attached to a lid for my boiler, so that the steam vents out of the window rather than filling the house...

Has anyone tried such a thing -- any pictures??

[hail_to_the_ale]

I've got a 2" chimney which I screw on top of my boiler as it comes to the boil, it does the job, taking all the steam directly outside no off smells or steamy windows on brew days any more

[Hawkinspm]

I've been looking at the same thing, was worried about steam condensing in the tube and dropping back into my boil. Also considered a dehumidifier next to the boiler ( but that was purely as a friend had one that he is not using).

Like the idea of the tumble drier vent more though I think - would be interested in pics of the chimney, do you use a fan as well at all or just let the steam naturally rise?

Thanks
Paul

[CJBrew]

Like the idea of the tumble drier vent more though I think - would be interested in pics of the chimney, do you use a fan as well at all or just let the steam naturally rise?

Thanks
Paul

Same question -- whether to put a fan in... Although it would probably need to be the same diameter as the vent (maybe 4") and made so that it would be steam-proof, so probably not cheap. I doubt you'd need a fan though.

It might appease the Lady, who was dismayed after the last brew-day to find the bedroom smelled of hops. I rather like it

[grmills]

A standard shower extractor fan kit will do the job you're after, eg http://www.tlc-direct.co.uk/Products/BG ... ce=froogle
I suppose it depends on whether you consider £22 to be cheap or not, running costs would certainly be less than a de-humidifyer.

[CJBrew]

perfect and I can buy one from about half a mile up the road from work... Just needs to be attached to some sort of boiler lid. Don't really want to knacker the lid that's on there (but I suppose that doesn't matter... hmm)