First of all, this looks so good and polished! It has a really cohesive style and the design is very charming.
Second of all, uh, I can't seem to drag the ingredients to the cauldron at all. I'm on Windows playing on Chrome, using left click and drag on an ingredient and nothing happens.
Also, a suggestion: with games like these, their strong point isn't focused on the gameplay, but rather the worldbuilding and characters. You could focus on that aspect a lot - after brewing, maybe it would be nice to see the bar in its entirety and see customers just hanging around in it, or find other ways in the game to explore the lore and hear the NPCS talk more, so that we're not always in the brew interface all the time. That way it becomes a very cozy game and adds some level of meta progression, if that makes sense.
I hope you keep working on this game!