Place a fine strainer over a deep bowl and line it with clean muslin or cheesecloth.
Pour yogurt into the centre of the cloth.
Gather the edges and tie them into a secure knot.
Keep a plate on the cloth containing yogurt to put pressure on it.
Refrigerate the setup (bowl with strainer and cloth) overnight to allow the whey (liquid) to drain out.
By morning, you should have thick, creamy yogurt with no whey remaining. If not, keep it for more time or squeeze it gently to remove the remaining whey.
Transfer Greek yogurt to a bowl once all the whey is drained out.
Store it in the refrigerator until you are ready to use it.
Notes
1 cup (260 g) of yogurt yields ½ cup (116 g) Greek yogurt.
The thicker your starting yogurt, the creamier and thicker your Greek yogurt will be.
Homemade yogurt set with full-fat milk gives the best results. Low-fat yogurt works too, but the texture will be less creamy.
Keep the set-up inside the fridge to prevent yogurt from turning sour, especially in warm climates.
Let the whey drip naturally. Pressing or squeezing the cloth can make the yogurt grainy.