brewing no,no

I brewed a LHB kit a while back and ruined a batch by trying to hurry. I partially covered the boil with a lid to heat it up quicker. all that did was keep the crap in the boil that was supposed to be removed.
never again!

I went back to my own rec. that was supposed to be a stout, which is really a good brown ale.
not covered og 1060
fg 1020

just racked it to 2nd today.
happy brewing, patients, patients, patients

Your statement makes no sense. Covering the kettle just slows the evaporation

Homebrewjosh said:

Your statement makes no sense. Covering the kettle just slows the evaporation

Click to expand...

No it doesn't. You need to boil uncovered to allow DMS to be driven off. If it's covered, DMS will stay in the wort, leading to off flavours.

I sometimes cover it while it gets up to temperature and then uncover it for the boil. But yeah, you have to leave the lid off to get the DMS out as PseudoChef said. That's also one of the reasons you need to chill the wort quickly. DMS production continues even after flame out.

I did the 'lid on' when I brewed my first batch. Never going to make that mistake again.

Patience....this isn't a hospital

Does it make a difference if the lid is on slightly covering but letting the steam out?

OK, I will ask. What is this DMS you guys are referring to. I have made several batches now and a couple have had what I think are off flavors but I don't really know. I have also partially coverred the boil kettle and I don't know if this is the cause. Thanks Paul

The home brewing Wikipedia has lots of really good information. If you haven't browsed through it, you should have a look. In the meantime, here's what it says about Dimethyl Sulfide (DMS): https://www.homebrewtalk.com/wiki/index.php/DMS

Thanks for the info, Fingers. I did not know what DMS was either.

I typically cover my brewpot to help get the boil going because it takes a long time on my stove, but take it off afterwards.

Very interesting information. I have always kept the lid on during the boil but after reading this, I now know better.

Yes, uncovered is the way to go. I normally steep in a seperate container, and then bring the other 4-5 gallons of water up to temp with the lid on, then I put the lid away and boil like that. Once the boil is done, and I put the chiller in, I then recover it after the boil drops down, to try to keep things clean, once it is not boiling, I don't want any critters getting in. I think recovering with a freshly sanatized lid, helps. Maybe it is not needed, but I am a clean freak when I brew. The key is not to rush, relax and have a home brew, while you brew more!

--John

Here's a question. I just brewed my first mini mash with a AHB kit. I steeped my grains in my main 20 quart pot and left the lid on to keep the temp consistant. Once that was done, the lid was removed and brought to a boil. I can understand removing the lid for the boil, but is it ok to leave it on while steeping?

mikes_brew said:

...patients, patients, patients...

Click to expand...

Did someone call a doctor?

It's fine to leave the lid on while steeping. You'll have quite a boil coming up. Steeping uncovered with extract would be like mashing uncovered in AG, and you won't see folks doing that.


TL

DMS will be produced as long as the wort is over 140f. A vigerous boil for more than 30 minutes is usually needed with the cover off and quick cooling of the wort to under 140f is nesessary to prevent DMS.

So is there a certain amount of time you need to boil the wort to avoid DMS formation, after which point you don't need to worry about it? Or is there always a risk of DMS, even after an hour's boil?

Yes most people boil 90 minutes to drive off DMS, its really a concerne when using pislner malt.

I boil ales for about 75 minutes and lagers for 90. Much of that is to avoid DMS.


TL

If you are doing extract I don't think DMS is a real concern. Whoever made your extract has boiled it already and diven off most of the DMS precursors (SMM) from the wort. In this case it may be OK to boil with the lid on, if necessary. Better safe than sorry, I say, but I don't think it should that big of an issue until you start steeping large ammounts of grain or mini-mashing