Wellington coffee enthusiasts know the truth: from the hidden laneways of Leeds St to the corporate hub of Lambton Quay, we aren’t just a city of coffee drinkers; we are the coffee capital. But while that daily flat white (or three) fuels our productivity, it also brings a challenge: tannins. These organic compounds are the culprits behind those stubborn yellow-brown stains that settle into your enamel. Because coffee is also acidic, it can temporarily soften your enamel, making it even…