It looked like thick milk, maybe cream, and it was just on the very bottom. It reminded me of what oil mixed with water looks like except it was very white. The engine oil is fine -- no evidence of contamination.

Thoughts?

 

It's not uncommon to see that in colder weather.
Moisture (from both condensation & combustion) accumulates in the crankcase on shorter, cool runs which don't heat the oil enough to evaporate it out fully, as it would in summer or on long drives.

 

If there a significant amount of water in your crank case and the motor has not been turned over it will be at the bottom of your oil pan. Drain a Lil out, if there's water in there it will come out first. But most likely it's just been to cold to burn off natural vapor condensation. Unless you've overheated significantly.

 

That's good news and all runs lately have been short. In fact the thermostat appears to be stuck open so she doesn't warm up like she should (new thermostat on order).

Overheating has not been a problem. The oil is fresh but this oil and the previous oil showed no sign of water contamination.

Thank you both!

 

Most likely condensation as has been suggested [above]. Some of my earliest automobiles were VW Beetles and a Karmann Ghia. It was not uncommon to find condensation [milky white goo] under the oil cap, during the winter with shorter trips.


Keep in mind... these were air cooled, so there was no water [antifreeze] to possibly get past the head gaskets.