Can I pour olive oil down the sink?

Don’t Pour Olive Oil Down the Sink—Here’s Why

It might seem harmless—after all, olive oil is liquid when you pour it from the bottle. But pouring it down the drain can lead to serious plumbing problems. Unlike water, olive oil doesn’t stay fluid at lower temperatures. When it hits cooler pipes, especially in colder seasons, it can solidify around 40°F or below, forming sticky clumps that cling to pipe walls.

Over time, these clumps accumulate, trapping food particles and other debris. Before you know it, you’re facing slow drainage or a full-on blockage. Even if your kitchen is warm, the oil can travel further into the sewer system, where temperatures drop, contributing to larger issues like fatbergs—those massive masses of grease and waste that plague municipal pipes.

So what should you do with leftover olive oil? The best approach is to treat it like other cooking fats. Let it cool completely, then pour it into a sealable container—like an old jar or a metal can. Once full, toss it in the trash. For small amounts, soaking the oil up with a paper towel before disposal works well too.

Some communities even offer grease recycling programs, where used cooking oils are turned into biodiesel. If you cook with oil frequently, checking for local options is a smart, eco-friendly move.

While it’s tempting to take the quick route and rinse oil down the sink, a little extra effort keeps your pipes clear and protects the broader water system. Your future self—and your plumber—will thank you.