Vapourising is an alternative to smoking. It is achieved by heating cannabis slightly less than would cause it to burn but sufficiently hot to cause the THC and other oils to be released as vapour. This vapour is then inhaled and absorbed through the lungs in a similar fashion to smoking. This has many advantages over smoking in terms of efficiency and healthiness and delivers a much faster hit than eating the cannabis.

Vaporizers of various designs (and spellings!) have been around for many years now and are often found in Dutch coffeeshops and in places like the Cannabis College, Hash Museum and Cannabis Cup venues. They employ a variety of methods of heating the cannabis and delivering the vapour.

Most of these contraptions use components intended for other purposes and have a slightly home-made feel about them. More recently some very sophisticated purpose-built vapourisers have begun to appear. These machines take less skill to use and are therefore usually more efficient. The challenge for any vapouriser is to ensure that exactly the right amount of heat is applied to all of the herb and then to deliver cool vapour. With basic designs there is a tendency to burn the bud and often some of the weed is too hot whilst other parts are too cool. This can lead to inefficiency or reduce the device to nothing more than a high-tech bong.

Hot air passed through finely ground grass seems to work best and this is the principle used in the most advanced designs such as the "Vapor Brothers", "Verdamper VaporHighzer" and "Volcano".

Since trying one in Amsterdam, I have been a fan of the Volcano vaporizer. This is the Rolls Royce of vapourisers. It pumps hot air through the marijuana collecting the vapour in a roasting bag. The steady airflow enables accurate temperature control making it very easy to use and reliable. Unlike many devices, it never burns the grass rather it delivers heat evenly.

Now its makers, Storz & Bickel, have sent us one to test. Everyone who's tried it has been impressed. Just a small amount of herb is sufficient to stone a room full of people because nothing is wasted on combustion. I have no hesitation in recommending the Volcano as the best but I'm glad I didn't have to pay for mine 'cos they're bloody expensive!

You can try out a Volcano vaporizer in any of these Amsterdam coffeeshops: Barney's, Blue Velvet, Bushdocter, Chocolata, Dampkring, El Guapo, Greenhouse Centrum, Grey Area, Homegrown Fantasy, Katsu, Kingstone, de Kuil (420 Cafe), Noon, Prix D'Ami, Rokerij, Rookies, Rusland, Sensi Coffeeshop, Smoking Bull, Softland, Tweede Kamer.