I’ll risk sounding like a snob while actually being an illiterate by saying this: drinking from a little porcelain teacup gives a much different, and nicer, feel than drinking from a big tea mug. And I’ll try to dissect the difference.
The teacup on the left was given for free at a colloquium on Korean tea ceremony. The mug on the right was bought for $25 at the Golden Tea Shop.
The enamel of the teacup is smooth on the lips. The shape of the teacup fits the opening of the mouth. When you drink from a teacup, there is plenty of open air surrounding your nose and a little bit of the tea aroma directly under, whereas when you drink from the mug, the entire nose is trapped in the heat and aroma of the tea, which tend to be suffocating. The teacup is shallow, allowing the tea to approach the lip faster than the tea in the mug, this amount of waiting time must also have an effect on the enjoyment.