A sour version of hell

Two weeks ago I brewed the ordinary bitter recipe out of BCS and I was just about to bottle it, but it tasted god awful... super sour. It also had this really weird looking film on it (see pic).


I've brewed about 20 batches using roughly the same technique, and only once did I have a horrible tasting undrinkable end result, and I am pretty sure that was caused by contaminated yeast. But this time it was a fresh batch of US-04. I pitched 6 grams (recipe called for 5 grams of properly rehydrated yeast for 5 gallons, and I brew 2.5 gallon batches... I've read that you lose about 1/2 of the yeast when you pitch them without rehydrating, so I figured just pitching 6 grams dry would be just over what I needed). I temperature controlled the fermentation at 65 F and raised slowly to 70 F over the last week.

Did I just get unlucky somehwere? Does anyone recognize the strange film? Just trying to learn from the experience...

 

What is it that you are fermenting in? That looks like a kettle. If that is a kettle, are you sure that it was sanitized properly before and air tight after?

 

Its highly unlikely that an infection came from a sealed packet of yeast.
Luck can play a part, but its more likely something with your equipment and/or process that caused a problem.
If you can describe your process and equipment used, someone here will be able to offer suggestions.

 

It's definitely a pellicle, definitely infected.

Second to the comments above.

And adding a bunch of dead yeast isn't good even if your pitching rate is ok otherwise. I'd rehydrate it properly and pitch only as much as you need. Although I'm not looking at the book, could have sworn it'd call for 11.5 grams and not 5.

 

11.5g is the normal rate for a 5 gallon batch. His batch is only 2.5 gallons.

 

Yeah I know but he said the recipe called for 5 grams. Which seemed odd.

 

Ahh ok, it's an Ordinary Bitter. That pitching rate makes sense then. Never mind me.