I purchased a Hario Syphon last week from Penny University and have been experimenting with it. Unfortunately since I am on holidays I have no thermometer and no portable gas burner so I must resort to timing and stove gas for my experiments. The results so far are not encouraging: there is a faint bitter note in every coffee I brew. These are definitely not bitter coffees (SqM Yirg, my own roasts of Coopedota Futura and Yemen Mokha Matari) and there is no bitterness at all when I brew them with the aeropress.
Can anyone help? Here is what I am doing:
1) pre-boil water, pour it into the bottom half, set up the top half, light the gas, wait for the water to be in the top half
2) wait 3 minutes, the time I estimate for the temperature to stabilise to somewhere around 85 celsius
3) grind using Hario Skelton on a relatively fine grind but nowhere near espresso, pour into water (dosage 60 g/l), stir for 15 seconds
4) stir again after 2 minutes
5) turn off gas after 3 minutes. The water will come down after 30 seconds and take about 5-10 seconds to drop back to the bottom part.
6) taste, wait a few minutes, taste again, etc.