Nettles (Urtica dioica) are in season at the moment, last year I was too late for this but today I'm making nettle beer with the first green growth. There are a lot of these free weeds around me, and dandelions (Taraxacum officinale).
Also brewing about the same time was brucedenney
There are many recipes which use nettles, but as far as I've looked they recommend young nettle tops, i.e. the tips of new growth.
I am working from this recipe
Nettles: ~2Lb (1Kg)
Dandelion root: 1x large-ish
Sugar (refined cane, white): ~1Lb (0.5Kg)
Ginger (dried, powdered): a large spoonful
Citric acid: ~1/2 tsp
Wine yeast compound: a sachet.
Fermentation bucket with lid.
Ex Newcastle Brown beer-bottles
Strictly speaking this may not be "beer":
OED: n.1 a an alcoholic drink made from yeast-fermented malt etc., flavoured with hops.
Although it goes on to say:
2 any of several other fermented drinks, e.g. ginger beer.
Step 1: Collecting Nettles
This week I noticed new nettle growth around my cottage. Remembering that I'd planned to make nettle beer last year but was too late in the season - this year I made a point of collecting some early.
Choose fresh, young and clean plants and only take the tops of (like picking tea). I used a pair of scissors and a glove because these plants are covered with irritant-filled hypodermic needles.
It's fairly obvious but - avoid plants which are harbouring insects or spider-nurseries, look diseased or eaten, are contaminated with soil, slug-slime or bird-turds etc.
You will need a lot, I collected two bags which was about the 2Lb the recipe requires. While I was at it I dug up a dandelion root to add in as well for bitterness.
Step 2: Mashing
Clean the dandelion root thoroughly and slice thinly.
Boil 2Lb (1Kg) of nettles in a gallon of water (4.5L) with the dandelion root.
I had to do this in two halves because I don't have a big enough pan.
Strain the liquid into a fermentation vessel, in this case a polypropylene bucket.
Dissolve 1Lb (0.5Kg) sugar in the liquid, I put some back in the pan and heated.
Add a heaped-desert spoon of powdered ginger and 1/2 tsp citric acid (or use the squeezings of a lemon)
Allow the mixture to cool, below 30oC (90oF)
Step 3: Fermentation
When the liquor is cooled enough sprinkle dried yeast compound on the surface.
In a little while the yeast will grow and convert the sugar you added to alcohol (ethanol). This is evident by foam and "brown stuff" on the surface .When it's done it will sink and the brew will look inactive.
Step 4: Done
When the fermentation is complete, add 1/2 a teaspoon of sugar to each pint bottle, and fill to the neck. Leave these until they look clear. I have crown-caps, a crown-capper and 40 pint bottles, but screw-top soda bottles would also work.
I never got these to clear completely (impatiently drank them after ~week).
The taste was a bit 'green' and a bit 'ginger', not unpleasant but not fantastic either.