Is This Right?

[Mainer]

Okay, so I'm doing my first sour starter. (I tried to do a Berliner Weisse without a starter over the winter, but it was a hot mess. Don't ask.)
Anyway, I pitched a starter ~48 hours ago, one packet of WY5335 into 2L of water with 200g Breiss Pilsen DME. It's been at ~80-85 since. I gave it a sniff and it's... well... not at all what I expected.
I expected sort of a bright lemony acidity coming through, but instead it smells like... molasses and balsamic vinegar together with something I can't quite identify. Basically, instead of smelling like lemonade, it smells like the baked bean factory down the block. There's no CO2 output, so I know it's not a yeast contamination.

I figure there are three possibilities:
a) I have a bacterial cross-contamination and should not pitch this into my wort.
b) I over-aerated the starter, so it's throwing off some acetic acid, but as long as I handle the wort batch okay, a little acetic in the starter won't hurt too much.
c) This is totally normal, and I'm over-analyzing. RAHAHB.

Thoughts?

 

[microbusbrewery]

Did you actually aerate? I've never experienced that kind of smell, but I don't aerate when I do lacto starters. In fact, I'll usually try to purge with CO2. To me, aerobic fermentation with lacto smells like a dumpster that's been sitting in the hot summer sun for a week or so. Is that the type of smell you're getting?

 

[Mainer]

It's not quiet that bad, but it *is* a little... manky. I didn't actively aerate, but I poured it through a funnel into a 1 gal fermenter and didn't purge. Also, it's a 2L starter in a 1Gal fermenter, so there's probably more headspace than is optimal.

 

[Mainer]

Like it's not *quite* summer-dumpster smell, but it's probably in that same family.

 

[tagz]

You have to be somewhat careful with lacto starters. Pay special attention to oxygen and temp. Don't expect it to taste dry and lemony, as the lacto won't drop the gravity more than a couple points and it will remain sweet. Having some way to measure pH is also helpful.

 

[Mainer]

Since I don't have ph testing capacity, I decided to taste instead of relying on smell. And it tastes fine. Not a bright acidity, but clearly there. I think it was just the acidity combined with the unattenuated graininess that was creating an unfamiliar sensation. I think we'll be OK.