A discussion about this on another forum got me thinking. Hypothetically, if the physiological effects of alcohol were not present, would people still enjoy drinking alcoholic beverages? Surely yes, now that we've been conditioned to like it. But I wonder if we found a sample of people raised in a non-alcohol-philic society (assuming there is one), and presented them with a variety of alcoholic beverages, they would enjoy any of them. Whatever they decide, is it despite the taste of alcohol, or because of it?
My guess is they wouldn't enjoy it. Alcohol is poison to us (and most other organisms as far as I know), right? So it would be only natural for us to find the taste offensive.
But on the other hand, fermented beverages also last because of that very same reason. And many people unknowingly took advantage of that fact to preserve beverages - wine, beer, etc. So maybe over the millennia of surviving on alcohol, we (or certain populations) have grown a penchant for it?
Primates and especially the great apes are as a whole fruit eaters (frugivores), which may be due to the inability to produce vitamin C edongenously. The fruit that is preferred is what we refer to as ripe to over ripe. the distinction between ripe and over ripe is arbitrary but refers to the level of decay the fruit is in and the level of ethanol that is contained in the fruit. Given that several fruits could be consumed on one feeding, the blood alcohol levels would of risen to a level that these animals could of have a pleasurable sensation of drunkenness.
Ethanol is also a very volatile substance with a distinct smell to primates ( http://icb.oxfordjournals.org/content/44/4/315.full ). The smell could be easily sensed and leading primates to a food source. Thereby it is an evolutionary consequence that humans have an attraction to alcohol.
I do love the taste of a nice full bodied shiraz, that said, it was an acquired taste.
I grew up in a very Fundamentalist home - no smoking, no dancing, no swearing, and definitely no alcohol. (My mom who is 88 has never drank any alcohol.) I tried to drink when I was in my early 20's but I never could stand the taste of beer, wine, or liquor. So now I just don't drink.
On the other hand, I didn't like the taste of coffee when I was growing up. I didn't start to drink it until our third baby was born. I needed something to keep me going after being up all night with bottle feeding and diaper changing. Now I really enjoy the smell and taste of a good cup of coffee.
Let me put this as plainly as possible. I don't like beer, wine, or distilled spirits because my society conditioned me to. I literally ENJOY these things. And, yes, they do taste good to me.
Also, while you did mention that alcohol is a poison (along with lima beans, kidney beans, nutmeg, almonds, stone fruits [peaches, cherries, plums, etc.], tomatoes, and potatoes)*, you didn't mention that it's addictive, another reason we like it.
You need to be a little more specific about the ability of alcohol to preserve. It has to be in a certain concentration. Beer and wine will spoil in no time exposed to contaminents in atmospheric air or a few fruit flies (aka wine flies or vinegar flies).
* source for list of poisonous foods.
It's often the case that the dose makes the poison.