Black gunk is never a nice sight in the kitchen sink. If you have this problem, you’ll know what I’m talking about – it’s the black, slimy residue that sits on the spokes of the drains. It might be on the strainer or beneath it on the plug itself. Either way, it’s awkward to clean and ends up becoming a permanent feature.
My kitchen sink has suffered from black gunk for some time; I’ve tried to shift it with my standard kitchen cleaner, coupled with a microfibre cloth, but it barely makes a dent. It’s difficult to remove all traces and whatever is removed seems to grow back in no time at all. So, I decided to put a stop to my black gunk conundrum and find a permanent fix. Here’s what you need to do and how to stop it from coming back.
What is the black gunk in my kitchen sink?
Black gunk is what happens when food, grease, soap scum and residue gets caught and is left to rot and grow bacteria, mould and fungi, forming what is known as a ‘biofilm’ – a microscopic colony of bacteria. It often happens in drains that are left cluttered and are rarely flushed but remain damp and stagnant.
For myself, it can be found in the 1.5 bowl of my kitchen sink (the one intended for rinsing vegetables but rarely gets used). There are often items left here that need to be hand-washed at the weekend, but in the meantime, they block the ventilation and contribute to bacterial growth, as does whatever drips down.
There’s likely biofilm within the pipes of the drain if you have it on the surface; this can encourage the growth around the plug via released spores and reproduction. That means you need to deep-clean the drain if you want to put a stop to this residue.
How to remove the black gunk from your sink
The first step is to clean the biofilm from the plug itself. To do this, remove the strainer and the plug (if you can), then scrub both carefully in hot, soapy water, using a toothbrush to get between the spokes. A toothpick can help you to poke through any awkward gaps. If the biofilm is still not coming away, you can always soak the plug/strainer in hot, soapy water for 20 minutes first.
You need to deep-clean the pipes beneath your plug, too. Start by using a drain snake to dislodge any blockages. Feed it in slowly, then rotate the handle when you feel resistance to catch and pull out the residue.
Once any blockages are removed, you need to clean biofilm from the walls using an enzyme-based drain cleaner. Ideally, you want one that’s preferably non-toxic and bleach-free, so it won’t harm marine life, such as Ecozone Kitchen Drain Unblocker. This will break down any remaining grease.
Alternatively, if you’re looking for a home remedy, you could also try flushing soda crystals down the drain. This is a natural solution which will also dissolve grease and grime. You need only tip 200g down the drain, then wait 5 minutes and flush with hot water, and that’s it! Flush again a few minutes later to remove final traces. All in all, it should only take about five minutes to clear the biofilm, but longer may be needed in stubborn cases.
How to stop black gunk from coming back
You’re going to have to change your habits to put a stop to this residue. First, you need to remove any bits of food that get caught in the strainer sooner rather than later. Scraping your plates thoroughly before you rinse them will help with this.
GHI tip: Don’t bother rinsing plates if they’re going in the dishwasher. You’re just wasting water, energy and time! Scraping is still essential though.
Make a conscious effort to empty the sink strainer daily to remove any fresh deposits, giving it a wipe and a rinse with soapy water if it’s not often used to help clear any grease and grime.
You also need to keep the drain clear of biofilm in the future, too. Enzyme sticks can help to shift fresh deposits, as can applying 125g of bicarb, followed by 125ml of distilled white vinegar to fizz away residue. Do either of these monthly and make sure to flush the drain routinely to prevent stagnant water and discourage drain flies.
