I have asked the following question before: Is it safe to only rinse visible residue from container if I then refrigerate the container?
I've gotten some great answers to it which help me further understand the variables at play here, but I stubbornly suspect a large part of their final conclusions was influenced by gut instinct, rather than genuine consideration of the scenario vs. other more traditional practices that are considered food safe.
(EDIT: I was wrong! It appears the defining factor here is the bacteria that would be introduced by eating - specifically the stuff in the saliva that would be transferred into the container via cutlery.)
I've then decided to ask a more specific, more rigorous question, which would hopefully help me decide whether I am wrong in this analysis, and if so, why. I propose two scenarios:
Say I came up with a hypothetical monster recipe that included some scrambled eggs, pot roast, broccoli with cheese, steak, and black bean chilli. Then I took half of it, had a horrible time eating it, and left the rest in the fridge until the end of the night, when I reluctantly ate the rest.
(Wow, that wouldn't be a very good recipe! Yes, I agree.)
Say the next day I decided that all that stuff would taste better separately, and prepared each meal individually throughout the day. I then ate each meal off the same dish, rinsing it afterward in a manner that would remove all visible residue from the dish.
For the purpose of the question, assume I rigorously measured the total sum (food+container) of time spent in the temperature danger zone, including transportation, preparation and storage, and taking into account time to cool down in the fridge etc, and it added up to exactly an hour and thirty minutes in both scenarios. I am aware it would be more difficult to perform such a calculation in Scenario 2.
I know Scenario 2 sounds more gross, but are there factors that make it worse from a food-safety perspective than Scenario 1? Would Scenario 1 be considered not food safe by government standards (due to cross contamination and mixing a lot of foods)? If not, why would Scenario 2 be any less safe? One could argue it would be even more safe, given that there is way less food in the container most of the time (a microscopic amount).
The only thing I can think of that would make it worse is the potential presence of saliva in a dish I've eaten in vs one I haven't, which would interact with the microscopic residue left on the dish - but I imagine the water would readily rinse away the spit.