Unknowingly Drinking Alcohol
Did I break my 5th precept?


In order to break the 5th precept, the following four factors need to be present and fulfilled:


  
  Mada-niyam -- intoxicants. 
  Patu-kamyata-cittam -- the desire to drink. 
  Tajjo vayamo -- the effort is made. 
  Pitappa-vesanam -- the intoxicants being drunk passing the throat.
  


Very importantly is the second factor, i.e. the desire to drink. This is also known as intention/volition (Cetanā).

If just one of these factors are not fulfilled, the precept is still intact.