I read that as any of their varieties under 20% alcohol content you can get up to 20 litres worth total.
If it happens to be over 20% alcohol content this is reduced to only 5 litres total.
So Rock Hopper you could happily get up to 20 litres worth based off that…
No more than 20 litres of liquor with alcohol content not exceeding 20% by volume; or no more than 5 litres of liquor with alcohol content exceeding 20% by volume. guess their ROCK HOPPER IPA wont be included :(