What an amazing recipe! I should reduce the number of stars because the instructions need work -- but the flavour is so outstanding that I'll just suggest changes. You need to explain when to add the basil and lime juice. This is what I did. I boiled the sugar, water and zest for 4 minutes -- then turned off the heat and added the basil and juice of 5 very plump limes. I let it all cool for an hour so so. Then I put it through the sieve and poured it into a freezer-proof container. It has taken more than 4 hours for my mixture to set. But I have thoroughly enjoyed tasting it every step of the way. This is one killer recipe.