I have been playing oboe for over six years now. I've gotten pretty good, and have been through every reed texture. Until I know how to make my own reeds, I buy them from music stores. I played on hard reeds for a long time but recently switched back to medium. However, my dad bought three hard reeds on the internet a couple weeks ago, so I decided to break them in early so they would be ready when my current reed wore out. So two weeks ago I pulled out a hard reed and began to try to break it in. I have been trying for these past two weeks, yet the reed is still not playable! It used to only take me a few days to break in hard reeds... I've tried playing on it, soaking it in my mouth, soaking it under a faucet, and I even soaked it in a bit of water overnight! This reed is extremely stubborn! Someone suggested to me I soak it in vinegar. Will this work? And will I be able to get the vinegar taste off of it if I do? What other ways can I can break this reed in before my current one wears out in about two weeks? And do you have any idea why it's taking so long?

It sounds as if that reed is far too hard & no amount of soaking in water, vinegar or gin will get it right. You need to learn how to scrape reeds to make any progress with it - asking your teacher or an experienced player for help will be the easiest way forward on this.

Yeah it looks like you would probably have to adjust the reed in someway if you really wanted it to play. What brand is it? And if I may, here is a good reed maker who sells homemade reeds. I've started getting my reeds from him.

http://www.reedmaker.com/index.html

soaking reeds in various liquids left over from the German system oboe. Its specificity was such that the stick is gradually grind, and because of the long grinding, gradually loses its elasticity (despite naliichie in sharpening pronounced "back")gradually, the water went over to the black tea. some extremals, trying to revive the good, but the old stick, dipped in a split second her pen in the boiling water.
own experience making reeds for oboe, I can say one thing: the initial stiffness of cane ago did not return any methods.ferments contained in the saliva, are doing their job. even if you soak the cane in vinegar, yes, the material becomes harder for a while, but the source characteristics are not achieved.