Welcome zazasnana. A flare up is a period of time where you go through symptoms and feel poorly. Sometimes, Crohn's patients experience periods of remission as well where they feel normal and don't have symptoms.
Regarding your taste question, do you mean that you mean that you have lost your appetite? It's very common for me to lose my appetite while flaring, but it's important to be sure you're getting sustenance. Do you keep a food diary? It might be a good way to keep track of foods that work well or that you should avoid while flaring?
I hope you enjoy the forum as much as I have. Lots of good folks here who can understand you like no one else can!