How long does grout take to dry?

Grout takes 24 hours to fully cure and dry. When grouting tile, it's best to let the grout cure for 30 minutes before wiping each tile with a slightly damp sponge.

According to This Old House, grout should be mixed according to packaging directions and allowed to set for 10 minutes. This time allows a chemical reaction called slaking to occur. Slaking is when the pigment, cement and sand combine to create a consistent color and thickness. After 10 minutes, grout should be stirred again and then worked into the tile joints using a rubber grout float held at a 45-degree angle.