I made a bean/lentil salad. With carrot, celery, onion and tiny bit of oil and vinegar. How long can I keep it in the fridge?

It's my very first time ever using lentils. I didn't even know there were different kinds haha

My question to you would be how long do you WANT it to last? From the sound of it, I'd estimate probably 5 days -- but won't it be eaten before that? Some lentils are sturdier than others. You haven't said what lentils you used. For example, the French Le Puy lentils hold up much better than red lentils, which tend to get mushy pretty quuickly.

And when the beans/lentils start to get mushy, you could puree them and add them to a winter vegetable soup. You may have to adjust the soup with some sweeter vegetables (like sweet potato) if the vinegar & oil shifted your beans/lentils to the tart side.

ChezHenry and Uncle Jess make a good point - they would be quite edible for a few more days but the texture is going to change. So at that point they would be good not as a featured dish, but as a mix-in: you could add a few spoonfuls to some other kind of salad. Or use them in a sandwich or pita or taco with other ingredients. I'm thinking a layer of your lentils on a baguette with some thin ham or prosciutto. The vinegar and oil from the lentils would moisten the bread nicely.

I agree with Uncle Jess. You can freshen it up and if you happened to make your own beans, it will stay unmushy much longer. A friend of mine makes a vinegary 3 bean salad and puts it in big glass jars and gives it to those of us who crave it. It lasts at least 5 days with no mushy beans. It's usually gone in 5 days or less.

48 hours is a reasonable guess for "best if used by", but don't toss it if you go over. If it seems a little past prime, freshen it up with some herbs, chopped scallions, maybe some grapes or nuts.

WOH that's no time at all. Damn!!

I would say about 48 hours. The beans & lentils may get mushy after that. The acid in the vinegar starts breaking them down, plus they are just getting old...