[header] How to make hardened yogurt raisins [title] Gather your equipment and ingredients. [step] You will need a large bowl, sieve or colander and a clean, fine-weave, linen or fine cotton dishcloth or cheesecloth and 1 quart (approx 950mls) of yogurt. [title] Line the sieve with the dishcloth or cheesecloth and place over the bowl. 
[step] Fill the sieve with the yogurt and cover with cling film. Place in the refrigerator for at least 6 hours, preferably overnight.