Hi TebitEvas

I like the scientific approach your using in testing the temperatures of both your crock pot base, and the interior of your Pyrex jug before you use the real thing.
However, there may be a slight flaw in your results. The water your using instead of oil and weed will start to 'boil off' as it approaches 200 degrees fahrenheit, and therefore remain fairly static in temperature (It can't rise much above 212).

As the boiling point of any oil is far higher than water you'll (eventually) see a far higher temperature in the jug, although not as high as the crock pot base.

I'd suggest giving it another go using an oil (any cooking oil, but preferably the one you intend to use for consumption), and see what differences you record.
If you can post back later with your findings, and the make and model of the crock pot your using, that would be great info, and useful all round.

Cheers and good luck :thumbsup: