Green Beer or Lacto

[jrhammonds]

I just recently isolated and remedied a lacto infection I found growing in my march pump. Things were boiled, replaced, soaked, and sanitized. I'm fairly certain it's gone. That said,I just brewed an esb that finished active fermentation around day 4. After the 7th day I took a gravity reading and small taste. I am sensing sour/tartness. Not sure if its green apple like or not.
I know time will tell but I was wondering if it could be lacto? Can lacto even create sour flavors in 7 days? Thanks.

 

[Beernik]

Green apple is usually acetaldehyde. It's usually a sign of fermenting too warm or pitching too hot. It can also be a green beer flavor because its an intermediate step the yeast can take between sugar and alcohol.

If you leave the beer on the yeast cake longer, the yeast can continue to convert some of it the rest of the way to alcohol, thereby reducing the off flavor. So, if you only have a little bit of it, you might be okay. If you have a lot of it (I did once), you might be stuck with it.

I think you could get some Lacto souring after a week. I suppose it depends on how much you start off with.

 

[jrhammonds]

Thanks for the quick reply. The tartness isn't strong at all so if it is acetylaldehyde, I think I'm in good shape. I was also curious if one could even detect the effects of a lacto infection on day 7 of a primary ferment?

 

[SimonHucko]

lacto doesn't deal well with IBUs or alcohol, so unless you're doing a light lager you'd be hard pressed to get any lacto to grow and do their thing in your beer. sounds like it's just young beer, 7 days is nowhere near enough time for the yeast to finish out and clean up after itself especially if fermentation was less than ideal (which it typically is on a homebrew setup). give it another week in primary before bottling or kegging and you should be just fine.

edit: I posted this without really thinking about it. the desirable strain of lacto for Berliner Weisse, etc, doesn't deal well with hops but there are hop tolerant strains/species that could infect your beer. give it another week and you should be able to tell either way.