Stored Yeast Slurry Smells like Champagne or Acetyladehyde

[Nizmoose]

Hi Guys so I'm jsut a little curious as to why this is but my yeast slurry I store in the fridge before I pitch into a starter smells a bit like the green apple sort of Acetylaldehyde off flavour but I recognise it more as the smell of champagne. I should point out that my yeast is taken from a portion of the starters I make not the fermenter (the slurry is stored as it came out of the flask i.e. not with fresh water on top but with the starter beer on top, which is decanted away before I pitch the slurry into the new starter) so the yeast is very clean and my starters always smell neutral and not weird at all, its just the actual yeast in the storage jar before pitching that has this smell.

I'm inclined not to worry about it seeing as the yeast is producing healthy normal smelling starters but i am curious as to whether other people have come across it before? My only thought is that perhaps the starters being fermented either warm or not as long as a normal fermentation means there is some unprocessed acetylaldehyde in the slurry, my starters are fermented at 25c and only for 32-48 hours.

 

[glenwal]

My only thought is that perhaps the starters being fermented either warm or not as long as a normal fermentation means there is some unprocessed acetylaldehyde in the slurry, my starters are fermented at 25c and only for 32-48 hours.

Given a starter is basically a mini ferment, it will have the same of flavors/smells as a beer that was fermented under the same conditions.

It will probably taste really oxidised too (depending on exactly how your doing your starter).

Nothing to worry about if your not pitching the entire starter and only pitching the yeast.