It’s possible for mold to grow in liquids, especially considering the high moisture levels.
Mold is a living organism and can take root anywhere there is enough oxygen, moisture and a suitable temperature range. Hot temperatures would require less water for mold growth while cold temperatures would not allow certain types of molds to start growing. Different kinds of foods have different percentages of water content too – meaning that some foods are better equipped to keeping from getting moldy than others because they’re made out of ingredients that don’t contain much water. If you’re wondering if drinks can get mold or not then look at your drink closely and touch it with the back corner of your fork or other metal utensil to see if it looks slimy.