Pellicle in sour mash starter or something else?

36 hours in and I got this slimy goo as you can see in the pictures and the PH didn't drop at all with 2 cups of unmilled pilsner malt. Set the PH to 4.4 with lactic acid as well. We'll see how this batch goes for Sundays real brew day.

I couldn't tell if it was a pellicle trying to form under the plastic wrap because it was only seen where there was bubbles in the plastic wrap.

I boiled the wort and cooled to 120 then threw in the 2 cups of unmilled malt. Sanitized the pressure cooker bowl that the 4 quarts of mash was in as well as the plastic wrap.

The PH dropped from 4.5 to 3.9 within 24 hours mind you so something is in there dropping the PH.

Could be anything. Grain is covered by so many things it would be a complete guess what it actually is. I've been making lacto cultures from grain in quart jugs with an airlock.

If you pre-acidify like you did, I'm not convinced that you need to keep temps high. High heat favors the lacto, but so does low pH. With an airlock to keep out O2, I haven't seen anything except a healthy kräusen from grain. Might be worth a shot?

Yeah you're throwing all sorts of bugs in when you toss in grains. I would expect all sorts of nasties. Pellicle? Yes absolutely.