When you open a fresh jar of peanut butter do you only work through one side until it is completely empty then start on the other side?
Or when you get those shallow tubs of hummus does it have to make it back home undisturbed? Then one of the baggers at the grocery store shoves it sideways into the bag completely ruining the symmetry.
Absolutely no digging in to the tub of butter, and no other food bits (usually bread crumbs) must be left inside.
If dug in to, it must be smoothed out before putting back in to the fridge. As for the crumbs, take them out and put them back on to the bread they came from. Now the butter can be put back in to the fridge.
I'm not sure. My partner isn't as pedantic as I am, so I end up scooping his day old crumbs on to my toast the next day.
I love that you buy in bulk because you're right - it definitely is cheaper buying more if you can eat it all before it spoils. What kind of foods do you make with cream cheese? Genuinely curious. I love cream cheese but I can't finish it fast enough.
My rule is that if you intend to touch the butter/spread/sticky stuff with a utensil, that utensil cannot touch the bread. You just drop the portion on the bread from a height until you think there's enough to cover it, and then you can spread it with that utensil, but if you need to revisit the jar, you need another fresh utensil.
You can't get crumbs in there if there's no cross contamination from the equipment to begin with!
You get better at estimating over time, but having one extra piece of cutlery to wash occasionally is less infuriating than unexpected stale crumbs and food that spoils more quickly from the contaminating yeasts and other organisms.