AG Eruption - we learn from our mistakes:(

Just brewed an AG batch of Cream Ale for some light Summertime enjoyment. All went well with the Mash and Sparge (first time doing a batch sparge). I nailed the pre boil gravity.

However, when I went to boil, i placed a lid on the keggle. BTW, new keggle...old one did not have a lid. My thought process was that, with a mild breeze, putting a lid on the keggle would keep air blown particles out of my wort. Also, it seemed to boil faster and hold its temp with lower gas consumption.

Problem, when I went to the fermenter, I had over 5 1/2 gallons of wort. To make matters worse, I did my first yeast starter with a DIY stir plate. Good news is that the fermentation process really took off. Bad news is that I had foam everywhere this morning.

I am going to need to remove the lid and airlock and clean both off and re-install. Not sure how this one is going to turn out. With a gravity of 1.032 going into the fermenter, I am going to have a very low alcohol level and I am not sure what the eruption is going to do to the process. I imagine that I am losing some active yeast out of the foaming catastrophe. Almost tempted to chuck it and start over.

invmgmt said:

However, when I went to boil, i placed a lid on the keggle. BTW, new keggle...old one did not have a lid. My thought process was that, with a mild breeze, putting a lid on the keggle would keep air blown particles out of my wort. Also, it seemed to boil faster and hold its temp with lower gas consumption.

Click to expand...

The point of boiling is drive off dimethyl sulfide (DMS). Boiling with the lid on prevents the boiling off of DMS and usually leads to boil overs. DMS tastses like cooked corn.

You can leave the lid on until you get the wort up to a boil (that's what I do) but you need it take off once you've reached boiling.

I usually leave my lid about halfway on during wort boil but enough that the wort can boil down properly and breathes. I have had particles, bugs, sticks and grass land in the wort at one point in time or the other. I just dig them out as best as I can, keep boiling and if I missed anything, it usually settles out during fermentation.
As far as your fermentation explosion goes, I have an AG Dead Ringer IPA batch I had the same issue with from this past weekends brew as well. It may not be due to your volume, but just the yeast you pitched as it was done with a starter. My AG DR IPA batch was pitched with a starter I made with the WL-001 strain and it just took off like a rocket. Even at 68 Degrees in the fermenter, I had to rig up the blowoff tube after waking up the next morning and seeing the airlock full of crud and the lid looked like it was going to blow off the bucket..lol
It happens..I would just clean up the outside of your fermenter as best you can, leave the inside alone(opening it introduces more risk of infection) and rig up a blow off tube and let her ride. I bet it turns out great!
:rockin:

I use a large spatter screen that's normally used to cover frying pans on the stove. It lets the wort vapor escape, while keeping out all the things that seem to blow around in my patio like cottonwood tree seeds and dog hair.

Darwin18 said:

The point of boiling is drive off dimethyl sulfide (DMS). Boiling with the lid on prevents the boiling off of DMS and usually leads to boil overs. DMS tastses like cooked corn.

You can leave the lid on until you get the wort up to a boil (that's what I do) but you need it take off once you've reached boiling.

Click to expand...

There are MANY purposes in boiling wort per the IBD:
1. To sterilize the wort
2. To stabilize the wort (stop enzymatic action)
3. To evaporate unpleasant malt-related aromas/flavors -this includes sulfur products like DMS as well as Aldehydes (straw/grass)
4. To isomerize hop alpha acids so that they can be dissolved in the wort
5. To denature and coagulate proteins ala hot and cold break (aids clarity and flavor stability)
6. To develop wort color and flavor ala Malliard reactions
7. To concentrate wort strength

Definitely agree that kettles need to be partially uncovered primarily because of #3 and #7.


Adam