Boiling The Wort

  • Thread starter stormkloud
  • Start date
Australia & New Zealand Homebrewing Forum

Help Support Australia & New Zealand Homebrewing Forum:

S

stormkloud

Guest
Should I leave the lid on when boiling my wort. Ive heard that you should leave it off.
 

Ross

CraftBrewer
Joined
14/1/05
Messages
9,262
Reaction score
371
Leave it off - you heard correct :beer:
 
S

stormkloud

Guest
Thanks Ross, what are the benefits and why.
 

Ross

CraftBrewer
Joined
14/1/05
Messages
9,262
Reaction score
371
Extract from J palmers "how to brew" www.howtobrew.com

The number 1 online reference book for brewers - If you haven't read it, then do!!!

"Covering the pot with the lid can help with heat retention and help you achieve your boil, but it can also lead to trouble. Murphy's Law has its own brewing corollary: "If it can boil over, it will boil over." Covering the pot and turning your back on it is the quickest way to achieve a boilover. If you cover the pot, watch it like a hawk.

Once you achieve a boil, only partially cover the pot, if at all. Why? Because in wort there are sulfur compounds that evolve and boil off. If they aren't removed during the boil, the can form dimethyl sulfide which contributes a cooked cabbage or corn-like flavor to the beer. If the cover is left on the pot, or left on such that the condensate from the lid can drip back in, then these flavors will have a much greater chance of showing up in the finished beer."
 
S

stormkloud

Guest
Thankyou, good site here too by the way.
 

Tony M

Well-Known Member
Joined
20/4/04
Messages
853
Reaction score
12
I make a practice of replacing the lid after the addition of the late hops on the premise that the wort has been boiling for an hour so the undesirables have departed and the oils etc in the hops that we are hoping will impart great flavour and aroma are better off in the brew rather than on the garage roof.
Please correct me if I'm wrong.
 

jayse

Black Label Society
Joined
25/7/03
Messages
3,402
Reaction score
12
Tony M said:
I make a practice of replacing the lid after the addition of the late hops on the premise that the wort has been boiling for an hour so the undesirables have departed and the oils etc in the hops that we are hoping will impart great flavour and aroma are better off in the brew rather than on the garage roof.
Please correct me if I'm wrong.
[post="53715"][/post]​
that is not entirely true. It is my understanding that DMS can and does continue to be produced while the wort is still at near boiling temp but not boiling, to what extent and wether you can taste it or not i don't really know and haven't picked it in any brews that have taken a long time to cool.

I put the lid on just before flame out also and don't have any problems iam just saying it is not techincally true to say DMS isn't produced while its not boiling and the wort is still very very hot.
It is produced but it isn't driven off so either way with a lid on it makes no difference as it needs to boil off to drive it away. While its hot but not boiling it can form but isn't driven off, at least as well as it would while its boiling anyway.


Jayse

Jayse
 

Tony M

Well-Known Member
Joined
20/4/04
Messages
853
Reaction score
12
yes Jayse,
I remember Wessmith saying late last year that DMS takes about 90 min. to boil off completely, but i reckon after 60/75 min. there couldn't be too much left. After all, before that boiling thread ran, I never boiled beyond about 70 min, as I'm sure a lot of others did also. (good english Tony)
 
S

stormkloud

Guest
So do you have to allow more wort in the boiler?
How much in a percentage do you loose.
 

Kai

Fermentation Assistant
Joined
1/4/04
Messages
3,734
Reaction score
17
That would depend on your boiler, and its ratio of surface area to volume. Once you've done a few brews you'll work out what your evaporation is.

If you boil off too much, don't panic. You can always add more water.
 

jayse

Black Label Society
Joined
25/7/03
Messages
3,402
Reaction score
12
Tony M said:
snipped>>
there couldn't be too much left.

[post="53731"][/post]​
Its not so much a matter of you start with a wort with so much DMS and you need to boil for a certain time to evapourate it off.
You start with all the precursors to DMS which are created in the malting of the grain. While the wort is hot these precursors form DMS, even if you boiled for 70 mins it is still possible for DMS to form after that, it is being formed the whole time the wort is hot. When it forms in the boil it evapourates off.

I haven't really heard much of it being a problem even in very light lagers with malts which contain considirably more of the precursors to DMS, but my point was even after a long boil DMS can still be produced while the wort is still hot.
This is more a technical thing as even the most agricultural of wort cooling methods home brewers use seem to not be a problem.

Iam not sure if you remember wes correctly or not there. There may be significanlty less pressursors left to form DMS but all my research indicates that DMS can continue to form even after the boil while the wort is hot waiting to be cooled. As i mentioned its not really a problem for really anyone after all i haven't ever tasted it in a fresh wort kit which is allowed to cooled down naturally in the container but all the technical information says it is possible to be producing DMS the whole time the wort is hot.


Happy Brewing
Jayse
 

Kai

Fermentation Assistant
Joined
1/4/04
Messages
3,734
Reaction score
17
Yeah, it might still be producing it but I imagine by that point the majority of the precursors have already been used up and the sulphur compounds boiled off.
 

Peter Wadey

Well-Known Member
Joined
11/8/04
Messages
583
Reaction score
6
Location
Sydney
G'day ladies,
The yeast has been pitched and I'm just getting through my 2 litres of starter wort so sorry if my post goes abit wonky.
I remember stewarding for a gentleman ex shopkeeper/ brewer whose taste buds and brewing skills I respect.
Hmmm corn!. Chew Chew
Hmmm corn- as he proceeded through the flight.

So lid off until flame out when chillers are turned on and wort temp drops. Besides the evap out of the kettle is nothing compared to other usage on brew day.
Hell I can loose 400 litres a day from the pool during hot weather. (Shame, shame , shame).

Pete
 

Latest posts

Top