Maple syrup in stout wort

[Larryposte]

Hey there, my wort is ready and I’m planning to add maple syrup to it in order to brew something closer to a pastry stout than a regular stout. I have 22 liter of wort, how many maple syrup should I add to that before I make all of this fermenting?
Thanks in advance

 

[Steveruch]

I'd add it after primary fermentation is done.

 

[Jag75]

Never done that but a local Brewery has a Blood Red Rye that has Maple syrup in it. The brewer told me they add it towards the end of fermentation. He told me that yeast get lazy and doesn't ferment all the syrup . It is probably the best Red ive had.