Infected propper starter?

Out of a bit of laziness, I planned to use some Omega Propper Starter to make a quick yeast starter this morning. I opened up the can, which had a little bit of tension to it (not bulging, but definitely under some pressure) and it made a bit of a hiss when opening. Curious, I poured a little into a shot glass – and it was lightly carbonated! It tasted okay, but had a bit of tartness. I was a bit worried that this might have been fermenting in the can (maybe lacto?), so I dumped the propper and just used DME.

So…is it possible that this was infected? I have used propper once before, and don’t recall it being carbonated!

Not infected. The cans are carbonated by the manufacturer solely to strengthen them so that they survive the rigors of shipping. The cans get bruised and battered during transit and otherwise would possibly break open, even if they were well-wrapped in bubble wrap. That tension you describe ensures that the box you get isn’t soaking wet and sticky from smashed open cans. The tartness is simply carbonic acid.

I have never used a “proper starter” before (since, I mean, I’m lazy but come on…) but I think it is odd they would carbonate it since carbonation isn’t necessarily good for the yeast.

Interesting to know, and that all makes sense. I kinda wish they had mentioned that this was normal on the can – I associate carbonation in things that are supposed to be still with fermentation. Ah well! I’ll know better next time.

I am going to reach out to the manufacturer to suggest they put this on the cans whenever they do an update of their can packaging. My internet search skills are pretty good, and I didn’t find it on a search that way. I finally delved into an Omega website (not the Omega website, but propperbrew.com instead), and the info was buried in an FAQ.

Thanks for helping solve the mystery!

I’ve honestly never tasted it… maybe I should… but yeah, I’m sure all the cans are fine… if it’s funky or whatnot, I would contact them. I guess at this point you said you dumped it but still. I haven’t smelled anything off myself but throw it right on the stir plate so wouldn’t notice carbonation unless it was insane from previous experience.

Edit: I guess you found your answer [emoji28]

I use them all the time now. I guess I’m lazy but I don’t have to deal with DME etc. just easier.  But I still boil for 15 minutes. I just don’t trust adding distilled water and calling it a day.