Will old coffee in the refrigerator keep for 2 days? I like the acidic taste of old/stale coffee.

I left my coffee at my desk over the weekend, and on Monday morning I took a sip. It tasted good. I did not heat it up, I drank it at room temperature. 

But I read it is not advisable to drink coffee left out at room temperature because it is a medium for mold. 

If I left it in the refrigerator for 2 days will it be safe to drink?
If left at room temperature it would certainly become a pool of mold, but if you refrigerate it, especially for just a few days, it should be fine. You would do well to put in a sealed container and probably adding ice to chill it faster would be 'better' but just set in the fridge for 2-3 days (depending on what else is in the fridge) should be ok. 

Beyond that, taste is a personal thing and if you like it that way...go for it.