Sport Pilot Talk

So I had my Sting sitting for 3 months, waiting for parts etc ... We drained the fuel from the main tank but never bothered with the gascolator ...
So , opening the gascolator I found this :
Seems like a lot of rust ...
I pretty much only use non-Ethanol Mogas 91 and Swift Fuel 94 , and before I grounded the plane for 3 months, I was sumping regularly and never found any water ...
So where that came from ? Is bad fuel the only option or could that have come from some other source (air ) ? As I mentioned the plane was stuck in a heated hangar ( min 50 F ) for 3 months - what makes me wonder is that I never use Ethanol-based fuel and I never found any water in my fuel to begin with ...

It definitely had a slug of water in there. I have seen that before. It could have come from fuel evaporating in the bowl while it sat. The evaporating fuel cools the air causing the condensation.

It was under different circumstances, but I removed the carb bowls off a Rotax and sat them on a table while I was working. They had 100LL in them. After about 20 minutes there was water in the bottom of both bowls from the humid air and evaporating fuel.