I am in a high-end coffee shop in a tech-heavy area of San Francisco, staring suspiciously into a cup of espresso. This is no conventional coffee: it is made without using a single coffee bean.

It comes from Atomo, one of a band of alt-coffee start-ups hoping to revolutionise the world of brewed coffee.

“We take great offence when someone says that we're a coffee substitute,” says Andy Kleitsch, the chief executive of Seattle based start-up Atomo, from whose pure, beanless ground product my espresso has been made.

Traditional coffee substitutes have a reputation for not tasting much like coffee and are usually caffeine-free.

However, the newcomers intend to replicate one of the world’s most popular beverages from taste, to caffeine punch, to drinking experience – and the first of this nascent industry’s beanless concoctions have begun to appear.