Start by washing the broccoli thoroughly in cold water. Cut the broccoli into bite-sized florets. Blanch the broccoli by boiling it in a large pot of water for 2-3 minutes or until it turns bright green. Drain the broccoli in a colander and immediately transfer it to a bowl of ice water to stop cooking. Once the broccoli florets have cooled down, drain them again and pat them dry with a clean kitchen towel or paper towel. Try to remove as much moisture as possible at this stage. Spread the florets on a baking tray in a single layer and freeze for 3-4 hours. Now collect the broccoli and transfer it to airtight freezer bags or containers, removing as much air as possible. Label the bags or containers with the date and store them in the freezer. Frozen broccoli will last up to 8 months in the freezer.