there is another thread about this idea on the Newcomers to Recovery Forum.
The only difference to the idea of having a drink a day for 30 days as a test to see if one can do that to determine alcoholism, is that in the other thread, a doctor defined alcoholism to his patient as: if you can go 30 days without a drink" then you're not an alcoholic.
my humble opinion??
if you are an alcoholic of the variety described in the big book of AA, you will not be able to control your alcohol consumption after having 1 drink. 1 drink will lead to the phenomena of craving another.
And, if you are an alcoholic of the variety described in the big book of AA, you will not be able to go 30 days without drinking without experiencing the phenomena of craving, so perhaps one of those 30 day tests is a good idea.
either try to drink just 1 drink (1 oz of liquor or 4 oz wine) a day for 30 days. no more than that. Are you happy or are you wanting more? Are your thoughts consumed with having your reward/drink?
or
try to go 30 days with no drink and watch your mind. is it occupied with thoughts of your drinking?
You may learn some valuable information. good luck.