Despite the different methods used to make ricotta and cottage cheese, you can replace ricotta with cottage cheese in a recipe without ruining the outcome. Traditional Italian ricotta is made using sheep or goat milk, and though not a particularly strong cheese, ricotta does have an acquired taste. Alternately, cottage cheese has a mild flavor and slightly crumbly texture. However, it is a versatile cheese that can be used as a replacement for ricotta in many savory and sweet dishes.
Check the list of ingredients your recipe requires. Make a note of the quantity of ricotta the recipe needs, and then get the same quantity of cottage cheese. However, don't buy the reduced-fat version of cottage cheese: It's very watery, lacks flavor and is likely to make the recipe runny and ruin it.
Empty the cottage cheese from the container into a fine sieve. This allows any liquid to drain through, leaving behind solid cottage cheese. The less liquid there is, the more cottage cheese resembles the consistency of ricotta.
Follow the recipe until you get to the step where you need to add ricotta. Add cottage cheese instead, and then continue to follow the recipe instructions. The dish you make may taste slightly different since ricotta has a stronger flavor; it may also have a slightly more crumbly texture since ricotta is creamier.