We tend to only have soya milk at home. (We're not totally non dairy, risotto needs butter and toast needs melted cheese ). It's totally fine in tea but it can seperate and curdle when used in coffee . What I don't understand is how places like Pret a manager, Costa and (shudder) Starbucks manage to do soya milk coffees without this happening. I've tried heating the soya milk, putting the milk into the cup first and trying different brands of soya and coffee beans but the problem still happens. Anyone any ideas?