Does Lacto create a pellicle?

[jivex5k]

I've searched and it seems like it doesn't on it's own...
I did a sour mash last week and kept it under the heat lamp for 5 days, collected the wort Saturday and there was a strong pellicle on it.

The method I use for sour mash:
1. BIAB, sanitize pot/bag/spoon/everything that touches it with star san.
2. When mash is done, cool to 120F with ice bath in sink.
3. Throw in 2 handfuls of unmilled grain.
4. Cover mash with saran wrap (that's sanitized as well, just dunk it in star san).
5. Put pot lid on, cover with foil to keep light out. Place under heat lamp.
6. Rotate pot once a day, do not ever open.
7. After 5 days it's done.

When I collected the wort the saran wrap was all puffed up, assume it's from CO2 production which is great if it's true. But it also had a huge pellicle:

The sourness is great, super clean, no bad aroma at all. It seems like lacto shouldn't be forming a pellicle according to some searching though. Anyone have experience with this? Maybe it's some bugs that are on the grains besides lacto, but it has that signature lacto tartness for sure.

 

[WayFrae]

I am not 100% certain but I think lacto does create a pellicle.

 

[jivex5k]

I found it strange cuz this is the third one I've made, the first two didn't look anything like this one.
However I also kept this one warmer, rotated the pot, and didn't open it once to check sour level since I know 5 days is perfect for my tastes.

 

[Inkleg]

Don't have an answer for ya. Just wanted to say, good to see you here.

 

[jivex5k]

Haha what's up Inkleg? Small world (wide web). The good news about this pellicle is the sourness tastes great so...even if I don't understand why it happened this time I'll be happy if I can recreate it.

 

[dantheman13]

Keep in mind that there was a wide range or organisms on those grains you threw in.

 

[jivex5k]

Keep in mind that there was a wide range or organisms on those grains you threw in.

Whatever is in there is making some tasty sourness. I've been using the same bag of unmilled grain for every batch so I found it strange that this one had such a large pellicle where the other two didn't.

If I can re-create the pellicle with the batch souring now I'm gonna chalk it up to less oxygen exposure and a higher temp all and pot rotation.