Pilsener was originally a refreshing brew with just a hint of deadly poison for that extra kick.
Home-brewing beer has been a popular hobby since the law was changed more than 50 years ago to allow people to do it without a licence.
Enthusiasts like nothing more than experimenting with malts, hops and yeasts to create unique flavours, even if they’re so unique that only the enthusiast enjoys them.
People who happen to number a good and generous home brewer among their friends or loved ones count themselves fortunate, as they can generally look forward to an interesting drinking experience when invited over for a tasting session.
Of course, the interesting experience might also include a hangover so devastating that it mimics the symptoms of several grave illnesses, but it would be churlish to complain.
It is particularly fascinating to be invited to sample some ancient recipe the home-brewer has unearthed, and to experience an ale or porter the like of which hasn’t been tasted in centuries.
However, if our friend or loved one invites us to try an authentic pilsener we should exercise caution - especially if we have the slightest doubt as to their ability to follow a recipe accurately.
Or if we’ve left them money in our will.
When we think of pilsener we think of the familiar bottom-fermented and hop-infused lager which takes its name from Pilsen, the Czech city which pioneered the brewing style in the early decades of the 19th century.
However, Pilsen was known for brewing beer centuries before giving its name to a type of lager enjoyed throughout the world - and at least one of the flavourings of those old beers would get any brewer using it today shut down and possibly thrown in jail.
Henbane - Hyoscyamus niger - is sometimes seen growing on waste ground in out-of-the-way places, and thanks to its spiked leaves and rather sinister-looking yellowish flowers with purple centres the shrub is unmistakable when in bloom.
In folk medicine it has been used for pain relief and as part of a sleep draught, but in higher doses it can cause hallucinations, seizures and death.
It is also sometimes an ingredient in gruit, a mixture of herbs once used to flavour beers - notably in Pilsen.
Henbane has been associated by some historians with old folk tales of witches being able to fly; it is likely that many a henbane user became convinced that they could soar through the air.
There are still corners of the internet where intrepid - or foolish - experimenters report on their experiences with henbane-infused beer, but its use is generally not recommended.