Can the Crate of Alcohol be played if the wind isn't favorable?
A user on Board Game Geek sent a list of questions to the game designer, and the purpose of the Crate of Alcohol was included. A full list of these can be found here.

Regarding the Crate of Alcohol, game designer Oliver Pauwels replied:


  "Crate of Alcohol" pay 3 gold coins (as indicated on the bottom of the card) to activate this effect. Once you've paid the fee, the card is placed in front of you and stays there for the rest of the game. This does not give you any points, but it does lower your cost to throw cargo overboard for the rest of the game. A player can have more than one Crate of Alcohol in play, and the effects are cumulative (so two of them would reduce the cost of all cargo being thrown overboard by 2). Since no level 4 cargo are ever thrown overboard, this cost reduction NEVER applies to level 4 cards (for instance, a 2nd Crate of Alcohol still costs 3).


Additionally, the Crate of Alcohol is a Level 4 cargo. Pauwels also notes


  [T]he level 4 are special cargo. NONE of these cargo are thrown overboard and as such the color of the die rolls do NOT apply to use of level 4 cards (use them any time).


So it doesn't matter what color die you roll, but they are never counted as being thrown overboard.