Renew a granite worktop stained by cooking oil in Hong Kong

We've installed a new, light-coloured granite worktop in our kitchen but it has already become badly stained by spitting cooking oil. Is there any way I can remove the stains, and how should I seal the stone to prevent the problem from reoccurring?

The first thing I would try would be Miracle Stain Remover from Wing On department stores or A&A Building Supplies; 105-111 Thomson Road, Wan Chai. Tel: 2572 4381. It is an alkaline-based H69 solution which costs HK$80 per litre.

You simply soak a cloth with the solution, rub on and blow to dry, then repeat if necessary.

To protect your worktop from further damage, you could try A&A Building Supplies' IDS waterproofer (HK$240 per litre), which can be applied with a brush or cloth on granite or marble. Alternatively, you could use a clear acrylic moisture-resistant seal that gives a matt finish, available at Yuen Fat Ho, 77 Hollywood Road, Central (tel: 2546 8020).

With all these products you should test first in an inconspicuous area, such as under the countertop to check the stone doesn't react badly to the chemicals.

How Do You Remove Deep Oil Stains from Granite?

If the Miracle Stain Remover does not shift a particularly stubborn stain -- and I see this a lot in Hong Kong kitchens where serious wok cooking happens daily -- you need to try the poultice method. This is the technique professional stone restorers use, and it works on deep oil stains that have penetrated into the pores of the granite.

Here is what to do:

• Mix baking soda with water to form a thick paste (the consistency of peanut butter).
• Spread the paste over the stain in a layer about 5mm thick.
• Cover the paste with cling film and tape down the edges to seal it.
• Leave it for 24 to 48 hours. The paste draws the oil out of the stone as it dries.
• Remove the cling film, let the paste dry completely, then scrape it off gently with a plastic scraper.
• Repeat if necessary -- deep stains sometimes need two or three applications.

For really severe stains, you can substitute acetone for water in the paste mixture. However, make sure the room is well ventilated -- open the windows and turn on the extractor fan. In a typical compact Hong Kong kitchen, the fumes can build up quickly.

I should mention that the type of granite matters. Lighter-coloured granites like Bianco Romano or Kashmir White are more porous and stain more easily than darker varieties. If you have a light granite worktop and you cook with a wok regularly -- and let us be honest, who in Hong Kong does not -- you are going to need to be more vigilant about sealing and cleaning.

How Do You Protect Granite Countertops from Future Stains?

Prevention is always better than cure, especially with granite. Hong Kong cooking tends to involve high-heat wok work with generous amounts of oil, and the splatter from that gets everywhere. Here is my recommended protection plan:

• Seal the granite properly -- Apply a penetrating granite sealer once every 12 months. IDS Waterproofer from A&A Building Supplies (105-111 Thomson Road, Wan Chai, tel: 2572 4381) at around HK$240 per litre is a solid option. Apply it with a clean cloth, let it soak in for 15-20 minutes, then buff off the excess.
• Use a quality impregnating sealer -- For heavy-use kitchens, I prefer impregnating sealers over topical ones. They soak into the stone rather than sitting on the surface, which means they do not wear off as quickly. Expect to pay HK$300-400 per litre for a professional-grade product.
• Clean up oil splashes immediately -- Do not let cooking oil sit on granite overnight. Keep a microfibre cloth near the hob and wipe up splashes as they happen.
• Avoid acidic cleaners -- Lemon juice, vinegar, and many household cleaning sprays will etch granite. Use a pH-neutral stone cleaner. Lithofin MN Wash & Clean is excellent and available at most hardware shops for around HK$120 per bottle.

A simple test to check whether your granite needs resealing: drip a few drops of water on the surface. If the water beads up, the seal is still good. If it soaks in and darkens the stone within a few minutes, it is time to reseal.

Hong Kong's humidity actually works in your favour here -- the moisture in the air helps prevent granite from drying out and becoming more porous. But the flip side is that if oil does get into the stone, the humidity makes it harder for poultices to dry properly, so you may need to run the air conditioning while treating a stain.

If your granite worktop is beyond saving, or you are thinking about a broader kitchen refresh, you might also want to look at reviving your kitchen table or replacing cabinet laminates at the same time -- tackling multiple jobs in one go saves money on contractor call-out fees.

When Should You Call a Professional?

Most oil stains on granite can be handled with the methods above. However, there are times when you should bring in a stone restoration specialist:

• The granite is etched or scratched -- Oil stains are one thing, but if the surface has lost its polish or has visible scratches, that requires professional diamond polishing. Expect to pay HK$2,000-4,000 for a standard kitchen worktop.
• Multiple deep stains across the whole surface -- If the entire worktop is discoloured rather than just a few spots, a professional can strip and reseal the whole thing much more efficiently than you can with poultices.
• You are unsure what type of stone you have -- Some worktops sold as "granite" in Hong Kong are actually marble or engineered stone, and they require completely different treatment. A professional can identify the stone and use the correct products.

For more practical kitchen maintenance advice, browse our full kitchen repairs section.

Last updated: March 2026