Alcohol enters your bloodstream immediately you take that first sip and the effects kick in within about 10 minutes.  Your body absorbs alcohol into your bloodstream much faster if you drink on an empty stomach.  As soon as you have swallowed, the liquid goes to your stomach - where around 20% is quickly absorbed into your blood.  From there, it passes to your small intestine, where the remaining 80% is gradually absorbed into your bloodstream.  If you’ve eaten, it will slow the process of that alcohol passing into your small intestine.