Whilst in search of our Holy Grail of Gruit Ale as a nurseryman my first instinct was to grow all the necessary herbs. Our ancestors who produced gruit already knew the flavours that could be imparted to food by adding small amounts of woodland plants to their cooking. So naturally they would add them to ale too because they were readily available and free.
Sadly I don't have the breadth knowledge of wild flowers. If something other than what I planted in a pot comes up I call it a weed and pull it out. The heartfelt cry of nurserymen is now ringing in my ears 'If I could sell weeds I'd make a fortune!' Many of the gruit herbs we have been looking for are the weeds that I have discarded for the last 40 years.
A major concern is being sure that what we use is the right one, not a very similar one with some unfortunate side effects. So now I have resorted to buying weed seeds and growing them in pots. (The shame of it!) This is much easier than propagating some fancy ornamental that wants to grow in the tropics, not in a chilly Cheshire winter.
We are building up a small stock of Gruit herb plants which we will offer for sale with the Hop plants fairly soon.
Some of the gruit herbs can be acquired dried, but there is so much more satisfaction in producing your own, it's a stage further in the 'I made this!' thing. We have been experimenting making beer with our own Fuggles hops and made a very special brew. We should try a comparison brew of pellets to see if it tastes as good.
I did have a go at making tea with Peppermint leaves when we ran out of tea bags once, it had a flavour that was so much better than the shop tea.
Fortunately the information of what herbs were used in Gruit Ale is still available, but the quantities and method were not recorded. It's a bit like being given a list of ingredients to make a curry without being given the quantities and method. You could make a meal of sorts, but what it would taste like could be anything from fiery to disgusting.