Cut the elderflowers off the stem into a quart sized jar until it is almost full.
Pour the bottle of vodka over the elderflowers, then top with the slices of lemon to keep the flowers under the vodka.
Cover the jar with a lid and put it in a cool and dark place for 2-4 weeks.
Strain out the elderflowers with a fine mesh sieve, then add the optional honey or sugar and stir well or shake to combine.
It can be consumed right away or aged longer if desired. It will keep indefinitely.
