Anyone have some troubeshooting advise?

[ultraplop]

Hello,

I have been having some problems with my brews going bad. They generally start out pretty well and then go bad usually 2-4 weeks after primary fermentation is complete.

One of the things I noticed (while they still tasted good) is that they didn't seem very potent. So I started doing gravity checks for each batch and I found out that they are not fermenting as expected.

Most of my kits have come from Midwest Homebrewing and for example, two of the recipes I brewed recently had expected OG of 1.046 and expected FG 1.012. When I brewed them I hit the OG right on, but my FG ended up at 1.020 both times. They tasted a little sweet to me, but I couldn't tell if this was the beginning of infection or if I was tasting unfermented sugars. The last one I did, I let it sit in the secondary for a month and now it tastes vinegary. FG is still at 1.020

It seems that the fermentation is not completing and leaving sugars for other organisms to eat? Or perhaps my alcohol is getting converted to aecetic acid? I am not sure exactly what is going on or why I'm not coming closer to the expected FG.

I go to great efforts to sanitize the best I can, but it is clear that I am still getting infections. I have also started using an oxynator because I thought lack of oxygen may have caused a stuck fermentation.

My plan for next batch is to oxynate even more and I also plan on doubling my pitching rate by throwing in two yeast packets.

Does anyone have any ideas of what might be happening here or whats going on with my gravity readings?

 

[BeanPot Brewery]

You may want to try using starter to get your fermentation going quickly and vigorously. That may help fully ferment quickly enough to stave off any infections.
YOu may alsoi want to check you temps...maybe the ambient temp is fluctuating too much and you're getting off flavors from that.

I had some similar problems a few years ago and came to the conclusion that my plastic fermenting bucket had a few nooks and crannies that were hiding the nasties.

I swicthed to a glass 6.5 gal carboy as a primary and all has been well ever since.

Sorry I can't be of more help, but I'm sure somebody around here will have some good ideas.

 

[Jim Karr]

What kind of sanitizing regimen are you using? Starsan, iodophor?

 

[Brewpastor]

Sanitation and yeast would be the places I would start. Keep it all clean and use good, viable yeast in a large quantity. Aeration will help too. The thing that make beer go bad is wild yeast or other little meanies. So, kill the bad ones off, only put the good ones in and give them everything they need to do their job really well.