Pineapple can be drained using by pressing firmly through a fine-mesh strainer. To drain pineapple, pour the contents into a fine-mesh strainer. Make sure to place the colander over a bowl to catch the liquid if you need to reserve the juice. Gently shake or tap the colander to help remove any excess liquid from the pineapple pieces. Firmly press down on the pineapple pieces with a spoon or spatula to further drain the liquid. Once most of the liquid has been drained, you can then transfer the drained pineapple to a separate bowl or container for use in your desired recipe.