A plumber has issued a stark warning to coffee lovers: do not pour used coffee grounds down the sink. The practice, common among those using filter coffee machines or cafetieres, can lead to serious plumbing issues and hefty repair bills.
Why Coffee Grounds Are a Drain Menace
Alejandro from EJ Plumbing took to TikTok to explain the risks. "We've been asked if pouring your coffee grains down the drain after you're done having your coffee – is it bad for your pipes? Absolutely, it is bad," he said. "You are going to clog all your drains – nothing is going to drain, and you are going to have to get a plumber to come out and snake your pipes and remove all those grains that have been building up inside."
Unlike regular food waste, coffee grounds do not dissolve or break down in water. Instead, they compact and clump together. When combined with grease and soap commonly found in drains, they form a dense sludge that can block pipes.
The Science Behind the Blockages
Express Drainage Surveys explains: "Coffee grounds have a structure that is oil retentive, granular and fibrous, which means it shares similarities with other common offenders such as rice, pasta, eggshells and cooking oils." The oil residue sticks inside pipes, and when grounds bind to fats, they create an almost immovable layer. This slows water flow and encourages bacterial growth, contributing to the formation of fatbergs – large congealed masses that have become a notorious problem in UK sewers, particularly in London.
A Greener Alternative: Garden Fertilizer
Instead of pouring grounds down the sink, they can be repurposed in the garden. Former royal gardener Jack Stooks shared in a TikTok clip: "Coffee grounds can be used in the garden as a fertiliser. Like most fertilisers, it consists of the elements NPK: nitrogen, phosphorus and potassium." He recommends spreading them across borders to encourage flower growth. Coffee grounds also attract worms, which improve soil aeration. Additionally, used grounds can serve as thick mulch to suppress weeds, lock in moisture, and protect soil from wind and sun.
By following this advice, coffee drinkers can avoid costly plumbing repairs while benefiting their gardens.
