This might be the best bar sugar available...
And I still don't feel 100% confident, that I found the "final" solution for all my mixology-sugar demands.
However the Tate + Lyle Fairtrade Cane Sugar is the finest granulated sugar, which is currently on the market in the Middle East.
Yes, it is bleached, which might not be the perfect solution [unbleached would be better - but all organic unbleached caster sugar brands are just much coarser].
And it ain't cheap [while it is not as expensive as organic sugar].
But it is just the finest caster sugar available. And for those, who are concerned: it is made from cane sugar.
It dissolves easily in cold liquid.
Use your normal caster sugar, to make your syrups [well - you decide. Is "fairtrade" as important for you, to raise your cost?].
But for anything like a Mojito, Caipirinha, a Mint Julep or even sours and fizzes, it is a really good product.