Year old bottle dregs have pellicle and smell like feet

[KindofBlues71]

December 2014 I started saving dregs from wild/sour beer that I like. The first were dregs from several different sour beers from OEC, a CT brewery. I kept them in the same bottle and added dregs from Allagash, GI Lolita and a geueze.

My process from the start has been to flame the bottle top after opening, slowly pour into a glass until there's only a few mm left, then cover with sanitized foil.

Since I first started I've been doing the same thing with brett-only beers and some other sours until the bottom of my beer fridge looked like a sea of foil-topped bottles. I bought some 50ml centrifuge tubes and started transferring the dregs. When I came upon the OEC+ dregs I noticed that a pellicle had formed and the dregs smelled like feet/parmesan cheese.

Should I toss it? How long is it OK to keep dregs in a bottle topped with foil if I've been careful with sanitation?

 

[KindofBlues71]

Here's a list of everything in the single bottle:

Allagash Confluence 4/14
Castle Gueuze Fond Tradition
Goose Island Lolita
Hanssen's Oude Kriek
OEC Artista Zynergia Solaris
OEC Experimentalis w/ Meyer Lemons
OEC Phantasm Sour Blend #1
OEC Tempus #2
Relic Darkness Falls
Victory Wild Devil

 

[BGBC]

Try to make a small batch or at least a starter with it, then reevaluate.

Keeping it that long with only foil on top, it's probably taken in a lot of oxygen, leading to both the pellicle and the off flavors.

 

[Grod1]

Use a compound microscope or make agar and grow out the petri dish cultures.Than compare them to google pictures.