My from scratch goes fuzzy

One of the (few) disadvantages of cooking from scratch is that there is no best before date. Generally this means that the first time you find out that what you made won't last that long in the fridge is when it goes fuzzy.  As evidenced by my refried beans below.

I've tried to come up with a strategy for minimizing this but the reality is I cooking in batches so that I don't have to cook every night and at some point I'm going to end up wasting some food in order to learn it's best before.

The other thing that got wasted this week was some spinach. Despite my best intentions I just didn't get around to my greens. I think that part of the problem is that they sit in an air tight plastic container with their own moisture.

Next time I get spinach I'll try moving them to a bag with a bit of paper towel to cut down on moisture.