I have being looking for a recipe to use Chateau Cafe malt in and so i am in Belgium :). The boil time on most of the recipes are 90 minute but one which had this malt in it was for 150 minutes ???. Anyone have a good reason for this. The recipe was Pilsen 50%, Munich 25%, Crystal 12.5%, Chateau Cafe 12.5%. Not very fermentable so they suggest some sugar can be added. :-\
Some of Belgian recipes have incredibly long boil times some as much as 6 hours if you read that book on lambics. One reason given is caramelisation of the wort during long boiling.
Being doing a little investigation on this matter and reading advanced brewing techniques it is suggested that a long boil reacts with the sugars and amino acids to produce substances like melanoidin. This imparts flavour compounds like that of roast meat or baked bread. T'is this reason that some belgium brewers like to boil longer to bring in more complex flavours to their dark beers. :)
Melanoidin malt is a thing though. I'd rather keep in the good books with the missus and use that instead :)