Pouring cooking oil down the sink can lead to a blocked drain. The same applies to meat drippings, butter and greasy sauces. Even if the sink empties normally afterwards, fat and grease can collect further down the pipe. Let leftovers cool, then deal with them before you wash the pan.
What happens when you pour cooking oil down the sink?
Warm fat can flow easily out of a pan. As it cools in the drain, some fats harden. Grease can also stick to the pipe and catch other waste. Over time, that build-up can leave less room for water to pass. Severn Trent explains how household fats and oils contribute to blockages in its guide to keeping drains clear.
Hot water may help grease move past the plughole for a while. However, the water cools as it travels, so the grease can still build up further along the drain. Washing-up liquid helps clean the pan after you have removed the leftover grease.
How to get rid of leftover cooking oil
- Let the pan cool. Leave hot oil to cool safely before you handle it.
- Collect the oil. Pour cooled oil into a suitable container with a lid. If you have a large amount from a fryer, check whether your council accepts used cooking oil at a recycling centre.
- Wipe the pan. Use kitchen paper to pick up the thin layer of grease left behind. Then wash the pan as usual.
- Catch food scraps. Use a sink strainer and empty it into the appropriate bin after washing up.
For a small amount of cooled fat or grease, follow your council’s bin guidance. Also scrape greasy plates and roasting trays before loading the dishwasher, since its waste water still enters the drainage system.
What if you already poured oil down the drain?
Start by collecting and disposing of the next batch. If the sink begins to drain slowly, pay attention to which fixtures are affected and whether water backs up when you empty the bowl. A slow sink can have several causes, so mention the symptoms and any recent grease spills when you ask for help.
If the sink repeatedly backs up or other fixtures also start to drain slowly, arrange an assessment. In Coventry and the surrounding area, Central Drains can help with a blocked kitchen sink. Contact Central Drains and explain when the issue started and which fixtures are affected.