There are two kinds of charcoal you'll find in a shisha shop, and they are not interchangeable.

Coconut charcoal

Made from compressed coconut shell, sold as cubes (usually 22 mm, 25 mm or 26 mm) or flats. It has no added chemicals, so it doesn't affect the flavour, produces very little ash and burns for 60–90 minutes. The catch is that it needs a proper heat source to light — an electric coil burner is the usual choice — and takes 6–8 minutes to get going.

Best for: regular shisha use at home, anyone who cares about taste, longer sessions.

Quick-light charcoal

Round discs (33 mm or 40 mm) with a layer of accelerant so they light with a lighter in under a minute. They are convenient, but the accelerant gives off a noticeable smell and taste for the first few minutes, they burn out in 20–30 minutes, and they leave more ash.

Best for: bakhoor and incense burners, outdoors, occasions where you can't use a burner.

A quick comparison

• Lighting: coconut needs a burner (6–8 min); quick-light uses a lighter (under 1 min)
• Burn time: coconut 60–90 min; quick-light 20–30 min
• Taste: coconut is neutral; quick-light can taste chemical at first
• Ash: coconut low; quick-light higher
• Price per session: coconut is usually cheaper over time

Safety with any charcoal

Lit charcoal gives off carbon monoxide, which you cannot see or smell. Always use charcoal in a well-ventilated room or outside, never leave lit coal unattended, and never dispose of coal until it is completely cold — dunk it in water to be sure.