Most of us who grow herbs in our hydroponics eventually reach a point that we face the same question: What do I do with all these herbs? I tend to pick what to cook based on what herbs I have to hand, but even still, eventually I can't keep up with how much are growing.
For very short term storage, you can treat them just like cut flowers; place them in a cup or vase with water on the counter, or even in the fridge for slightly longer periods. But that still isn't a long term solution.
So, what to do with all the extra?