Process from https://www.growforagecookferment.com/how-to-make-a-gallon-of-mead/ On package of yeast is enough for 5G of mead - so only use 1/2 package for this and it should be adequate. Type of yeast will affect sweetness.
7.2kg honey 200g hibiscus flowers boiled in two 1.9 litre batches and strained. Second batch boiled a second time on 1 litre of water. Finished volume approx 8 litres. Topped up with water to make 10 litres. Placed in fridge to cool Pitched yeast at TEMP