December is a very busy month for London kitchen drain call-outs. The reason is simple. Christmas cooking makes far more fat and grease than a kitchen drain meets in the rest of the year. Turkey dripping, goose fat, roasting juices and gravy all go down the sink. Because fat sets inside the pipes, it builds up at bends, and the drain that was clear on Christmas Eve can be blocked by Boxing Day.
This is entirely preventable. Here is the advice that helps most, before the emergency happens.
Why Christmas Cooking Is So Hard on Drains
A Christmas dinner holds much more fat than a normal weekday meal. A turkey crown leaves a lot of rendered fat and juices in the roasting tin. Roast potatoes, pigs in blankets and rounds of gravy add more. A household that hosts a big meal can send more fat down the drain in one session than in the weeks before.
The problem is not only volume. It is also temperature and timing. Hot fat is liquid, so it flows easily at first. However, as it travels away from the sink, the pipe gets cooler and the fat sets on the pipe wall. In a cold winter pipe, it can set within a short distance.
Over several roasting sessions, the fat layer grows. Add food scraps, peelings and kitchen paper, and by the 27th the drain may stop moving.
What Never Goes Down the Sink
Turkey dripping and goose fat. This is the most common culprit. Let the tin cool, then pour the fat into a sealed jar or tin and bin it. Cold fat is solid, so it comes away cleanly.
Gravy. Gravy is liquid fat thickened with starch. It looks like liquid, yet it coats the pipe walls as it cools. A little is fine, but a full gravy boat poured straight from the pan is not.
Christmas pudding basin rinse. Christmas pudding contains suet. Because rinsing the basin releases fat particles, they build up in the pipe over time.
Cream and custard residue. Cream is high in fat. Wipe the jug first, and then rinse it with cold water.
Vegetable cooking water from roasting. If you add butter or fat to the pan, the water carries fat. Strain it through a colander before you pour it away.
What Should Happen to Cooking Fat
The cool and bin method. For a large amount, let the fat cool and set in the tin. Then scrape it into a container and bin it. Some councils accept solid cooking fat in the food waste caddy, so check your local guidance.
Repurpose it. Dripping and goose fat keep well in a sealed container in the fridge. They are excellent for roast potatoes or for frying vegetables. Because this was the original use of dripping, it is a good habit to revive.
The wildlife option. Fat from plain roasts can go into a winter bird feed with seeds. Use it only when the fat has no onion, garlic or heavy salt.
Protecting Your Kitchen Drain Over the Festive Period
Scrape plates before washing. Use a scraper or paper towel to remove food and fat before plates go in the sink or dishwasher.
Cold water rinse before hot. If any fat does reach the sink, cold water firms it up. The basket strainer can then catch it, while liquid fat would slip through.
Keep the basket strainer in place. The strainer is your last line of defence. Keep it in during cooking and cleaning, and empty it into the bin often.
Boiling water flush. For a drain that tends to gather grease, a weekly flush of boiling water can help shift it. Use plain boiling water, since washing-up liquid does not help the way people assume.
If Your Drain Blocks Over Christmas
A blocked kitchen drain over Christmas is fixable. It is rarely a full emergency, because only the kitchen is out of use. However, if several drains block, or sewage backs up, that is an emergency and needs help at once.
For a standard kitchen blockage, request a quote online via our contact form. If the same drain blocks every few months, a CCTV survey shows whether grease sits deeper in the system. Periodic jetting can then deal with it. Read our post on why Camden, Islington and Hackney kitchen drains block most often if you live in a Victorian terrace and the problem keeps returning.
What to Do if You've Already Poured Fat Down the Drain
It happens to most cooks at some point. If a tin of fat has gone down the sink, you have a short window to limit the damage. Run the cold tap on full for a few minutes at once. Cold water sets the fat into small particles, and these may pass through to the public sewer. Do not chase the fat with hot water, because that only moves the problem further along the run. There it sets again, in a place that is harder to reach.
If the sink starts to drain slowly within a day or two, that is an early sign of a grease plug. The 2017 Whitechapel fatberg was a huge mass of solid cooking fat and wet wipes. It shows what kitchen fat can do across Thames Water's network. The same process happens in a small way in home drains. Catching it at the slow stage is the gap between a routine jetting visit and a costly emergency after Boxing Day. For repeat grease problems, our kitchen drain blockage service handles the full clean-out.
Frequently Asked Questions
Is it okay to pour small amounts of fat down the drain?
A small amount of diluted fat rarely causes trouble at once in a well-kept drain. However, the problem builds up. Small amounts poured over months or years create the grease layer that blocks drains. So it is worth following the rule "never pour fat down the drain", even for small amounts.
Does hot water dissolve fat in drains?
Only for a short time. Hot water melts set fat, but the fat sets again as the water cools. It may push the problem deeper into the system. Products with caustic soda can dissolve fat, yet they need care, and they are not suitable for regular use in old clay pipes.
Can I use drain unblockers to clear a Christmas fat blockage?
Chemical cleaners can shift a light or moderate fat blockage. However, a solid plug built up over several cooking sessions usually needs professional jetting. Never use caustic products in pitch fibre pipes.
What's the emergency line over Christmas?
Request a quote online via our contact form. Our kitchen drain unblocking service covers London.
Why do London kitchen drains block more easily than elsewhere?
Victorian clay pipes in the common 100mm size are marginal for modern kitchen use. Their rough inside surface collects grease faster than smooth modern plastic. See our post on why Camden, Islington and Hackney kitchens block most often for the full explanation.
Because every property is different, start with our guides to blocked drains and pre-purchase drain survey advice. We also cover blocked drains in Edgware and blocked drains in Fulham, so you can see how the work runs near you.
