A simple kitchen mix is catching on, promising quicker clean-ups and brighter brews.
Households are turning to a pantry staple to lift stubborn coffee shadows without scratching prized ceramics. The method needs minutes, not hours, and relies on chemistry you probably learned at school.
Why bicarbonate tackles coffee stains
Coffee leaves behind tannins and oils that cling to the microscopic pores of glazed ceramics. These residues are slightly acidic. Bicarbonate of soda, an alkaline powder with a fine, crystalline texture, counters that acidity and adds a mild scrub that loosens the bond. The result is swift lift-off with light pressure rather than hard scouring.
Up to 98% of coffee discolouration can lift in 15 minutes on ceramic, porcelain, stoneware and enamel when a bicarbonate paste is allowed to rest before a gentle rub.
The contact time does the heavy lifting. Give the paste a short pause to neutralise and soften staining before you touch a sponge. That’s when the gentle abrasive action pays off, especially along lip lines and at the base curve where residue gathers.
The 15-minute method you can do now
What you need
- 2 tablespoons bicarbonate of soda (about 30 g)
- 1 tablespoon warm water (about 15 ml)
- A soft sponge or an old soft-bristled toothbrush
- A clean cloth for drying
Step by step
The clock matters: the 15‑minute wait softens stains so you can clean with a featherlight touch rather than force.
For very stubborn marks, add a small pinch of fine salt to the paste just before the rub. The larger crystals boost abrasion slightly without gouging a glaze when you keep the pressure low.
What to clean and what to avoid
This method suits glazed ceramic, porcelain, stoneware and enamelled steel. It also freshens many glass mugs, although a simple soak may be faster for glass. Take care with sensitive decorations.
- Safe: plain glazed interiors, printed motifs under glaze, enamelled camping mugs.
- Avoid: gold or silver edging, metallic lustre finishes, hand-painted decals, unsealed earthenware.
- Rinse thoroughly. Any alkaline residue can skew the flavour of your next brew.
Alternatives and when to use them
Hard water can complicate staining by adding limescale. In that case, adding a dash of acid at the right moment helps dissolve mineral crusts while the bicarbonate tackles tannins.
| Method | Best for | Dwell time | Risk level | Notes |
|---|---|---|---|---|
| Bicarbonate + water paste | Everyday coffee rings and brown shading | 15 minutes | Low | Gentle, cheap, fragrance‑free |
| Bicarbonate paste + a few drops of white vinegar on top | Stain mixed with limescale from hard water | 10–15 minutes | Low–moderate | Brief fizz loosens mineral film; rinse very well |
| Salt and lemon | Quick fix when you’re out of bicarbonate | 5–10 minutes | Moderate | More abrasive; test first on delicate finishes |
| 3% hydrogen peroxide + bicarbonate | Old, ingrained staining on light glazes | 15–30 minutes | Moderate | Spot test in a hidden area; keep away from metals |
If you try peroxide blends, wear washing-up gloves and keep the paste off metallic trims. Always test on the underside to check for colour fastness on decorative glazes.
Why mugs stain so fast
Tannins in coffee bind readily to tiny surface defects left by daily wear. Hard water minerals act like anchors, trapping pigment where glaze meets residue. Heat accelerates the bond as a mug sits between refills. Dishwashers sometimes set a faint film if detergent dosage or rinse aid is off, making the next round of staining quicker.
Tea can be worse. Black tea contains a higher tannin load and often leaves a matte film that needs the same alkaline treatment. The same 15‑minute bicarbonate method applies, though green tea films tend to lift even faster.
Keep stains away with small habits
- Swill mugs with hot water straight after use to stop tannins drying in place.
- Give heavy-use mugs a weekly bicarbonate wash; occasional mugs, a monthly refresh.
- Avoid wire wool and harsh scouring powders that can haze a glaze and invite faster re‑staining.
- Choose mugs with a light, high-gloss interior; smoother glazes hold less pigment.
- Mind milk proteins: rinse milky coffee mugs promptly, as proteins can bind pigments to the glaze.
A five‑minute weekly routine with bicarbonate prevents build‑up, keeps flavours clean and saves the need for harsh chemicals.
Costs, time and environmental angle
Bicarbonate of soda is inexpensive in the UK. A 500 g tub usually costs under a few pounds. Each clean uses about 30 g, so the cost sits in the low pence per mug. The method needs 15 minutes of dwell time, but hands-on work takes only a minute or two. You avoid chlorine bleach, strong fragrances and coloured gels that can leave aftertastes or irritate skin.
Used sparingly with light pressure, bicarbonate will not scratch a typical kitchen glaze. If a mug already shows craze lines or a matte, worn patch, switch to a microfibre cloth and skip any salt boost. When in doubt, test under the handle first.
Practical extras for tricky materials
Stainless steel travel mugs respond well to a bicarbonate paste rubbed along the grain, not across it, then rinsed very hot. Plastic lids benefit from a 20‑minute soak in a weak solution (1 teaspoon in 250 ml warm water), then a gentle brush around seals. Silicone gaskets can hold odours; sprinkle dry bicarbonate between uses to keep smells down.
If a mug smells off after a deep clean, fill it with hot water and a teaspoon of bicarbonate, leave 30 minutes, then rinse. For rare cases where brown ghosting remains, consider an oxygen-based laundry soaker (sodium percarbonate) diluted to label directions in warm water. Avoid chlorine bleach on crockery that contacts food or drink, as it can pit glazes and taint flavour.
