First off......if he is an alcoholic (only HE can admit that he is) then you must understand that he is not your problem to fix. I say this because so many loved ones and friends take on the burden of the alcoholic and feel they are somehow responsible when the truth is that only the alcoholic can and will get sober. That is something I wanted to make clear to you because so often others feel they can fix the alcoholic or they can change them. Being supportive is the best but focusing on yourself is key.
I would just sit him down and ask him. Not confrontational but when its just the two of you, then ask him about the drinking. Tell him your concerns. If reducing is drinking daily from the moment he is home for the night that doesn't sound healthy to me.
I drank, reduced (hard alcohol to wine) after my divorce and got sober when I accepted that I am alcoholic and told my partner. There is no reducing or moderating for the alcoholic. Even though I had cut some back....well I either drank or I didn't. I might go a few days a week with a drink but once I sat down and started....it didn't stop till i went to bed.
Keep in mind that the alcoholic is great at lying and hiding. You have only been involved 7 months, you don't live with him (im guessing at that one) and you really don't know all of his history.