As far as I know, all of Black Organization's members using the names of alcoholic drinks as their code name, like Gin, Vodka, Sherry, and Vermouth. Is there any reason behind this?
There is a reason behind this. Gosho Aoyama stated that there is a reason behind all the names of the, as we call it, Black Organization. He also said, that if we would knew the real name of the Organization, we would know the boss.
Now, we just have to wait until Mr. Aoyama reveals the real name. And it better be something better than "Bar", "Club" or "Organization of Alcoholic Drinks".
I think that there code names are base on there roles in the organization because sherry is made of grape that is good for medicine and her role is to make poison or medicament Vodka is made of potato and there are trades for poor peoples like the alcohol to so he do the trades like tequila that is also like vodka Another exemple calvados is a sniper and you all know the game shoot an apple on the head... So with those codes names the contact by telephones are at a minimum number because the phone number is the proof that she is a women that want to avenge her 7 child with the poison made by ai And because of her known that she can be a bar woman And because she called ai sherry and not xeres like in other languages we can know she is from england or america but the suspect number 1 if I am right is Yuzuki from the BAR POOL
Also, another useful information to note, Ano Kata chooses hard/distilled alcoholic codenames for male members (e.g. Rum and Gin) and sweet alcohols for females (e.g. Vermouth and Sherry), the boss is a person with very malevolent intents, he might have a keen interest in alcohols, so he might have chosen alcoholic codenamed for members.