The Portable Whiskey Jug is a one-handed item that can be bought from red chests for $30, as well as being able to be bought in Teamplay and Break Bad.
While holding the portable whiskey, if there is a team member in close proximity that has less than 100 health, the user can press mouse1 and heal the teammate. The amount healed is dependent on how much whiskey is in the bottle, which can range from 5 health to 50 health per bottle. The whiskey in the jug intermittently regenerates when it is not full.
Portable Whiskey can also heal the user as well, if the user's health is below 100%, but the health received is a fraction that the teammate receives. It also increases the drunken sway of the end user.
Portable Whiskey is a great team support option, especially in Teamplay where some maps do not allow for healing otherwise. Portable whiskey can gravely interfere with opponents attacking teammates by the simple virtue of forcing them to expend more effort to kill said teammate. However, portable whiskey limits the offensive capability of the user. The only offensive presence portable whiskey has can be achieved by throwing it at the enemy using the Handgun Throw perk. Using two jugs of portable whiskey is possible, and it allows for teammates to be healed very efficiently, but limits the user's offensive presence even further. The lack of offensive ability can be mitigated by using a one-handed weapon alongside it in order to avoid being a sitting duck.