People talk about how food is eaten to get a “grease coat” or to fill up. When you throw grease or oil down your drain, the same thing happens.
You will start to get a build-up of grease and oil. It won’t be obvious at first, but you will soon realize that it is there because the grease and oil will slowly clog your pipes and can cause serious plumbing problems.
Consider your pipes before you pour the cooking liquid down the sink. Choose a safer disposal option. Wait for the fat to solidify before you put it in your compost pile.