I'm looking at buying some 4.5L demijohns, I have found a recipe that I'd like to try. The recipe states to use 1L honey to 3L water and age for 8m-1y. Considering the demijohn is 4.5L and in total there will 4L in mass I assume that when I shake to mix the honey in it will dissolve somewhat and therefore there will be a little extra room after mixing, correct? Assuming that is correct and I give or take I will have around 0.6L of room in the demijohn. I hear you don't want a lot of room inside because it can cause issues. How safe will I be with that amount of room? Thank you.