Hi, waken, and welcome to SR. I'm sorry that you're having to experience his relapse when you're basically on your own. I'm glad you found SR. It's a wonderful group with a lot of experience, hope and support to share.
Originally Posted by
waken 
I looked through the pantry and noticed that he'd bought cases of beer and hard lemonade--which clearly isn't nearly as bad as the obscene hard liquour that he used to drink, but still REALLY alarmed me.
I can completely understand your alarm. My STBXAH went through one in-patient recovery program, came back still denying that he had problem. He tried to say that it was always the hard stuff, vodka, that was the problem, that beer was OK. It was an all out blatant denial of his alcoholism. (There were plenty of times where our living room was littered with empty beer bottles - not vodka bottles - and he was passed out on the couch.) There is no alcohol that is OK for an alcoholic. It all carries the same risks and dangers for the alcoholic.
Thinking that there is a 'safe' type of alcohol or drinking to just check on something are not signs of actively working recovery.
I'm sorry.
As the others have pointed out there is nothing you can do to make your father get back into his recovery program. You can express your concern, you can voice your support of his recovery, but you can't make him work his recovery. Your focus needs to be on you and your life; you have every right to focus your energies on your well-being. There is a lot of great information in the stickies (the threads at the top of the Friends and Family Forum) - especially (but not only) the "About Recovery" thread (great info on detaching, setting boundaries, excerpts from Under the Influence, etc.).
Welcome, waken, and hugs. Keep reading and posting, we're here to support each other.