a separate vent because they allow air to move through the drinking opening.
There’s generally no need to block the hole. It’s best to leave the lid’s openings unobstructed and use the cup as intended.
One important caution: coffee served in takeaway cups can be extremely hot. Avoid experimenting by shaking, squeezing, or tilting a full cup to test the vent, since hot liquid can splash onto your skin.
Is the Hole Also There to Release Steam?
Airflow and pressure can be affected by steam, especially when a drink is
