To replace cognac with fruit extract, use a simple 1:2 ratio, or 1 tablespoon of extract for every 2 tablespoons of cognac. You can use extracts from various tangy fruits like apricots, apples, ...
When he woke up, he used this idea of boiling twice as inspiration to better extract the soul of his brandy. The real story behind the practice of double distillation for Cognac is probably less ...