Barrel Char in a Jar. Despite what the Hydrometer Tests may have some believe I’m not a very “scientific” kind of person. I have been able to perform Hydrometer Tests on rum because it is very, very simple. I am no chemist the little science background I have was left behind aged 16, when I picked up a double award “B” grade in Co-Ordinated (Chemistry, Physics and Biology) Science at GCSE level in 1994.
