About the special custom drinks in mixology skill challenges

Hi, I'm curious about the 'special custom drinks'. My sims learned over 42 popular mixes from bars and lounges. then it says'a sim with this kind of knowledge can serve special cutom drinks;' My sims turned into mummy, simbot using the eliixers, then learned those specific drinks before achieving this skill challenges. My sims were able  to mix some veges and fruit into the drinks beoore this achievement. My sims were able to create their own custom drinks before achieving this.  Now I'm curious what the special drinks would be after completing this skill chlllenge. I'd like to learn more drinks. My sims learned every type of drinks in Sims wiki. Thanks.