Polish Cherry extract

[brianbrewed]

Am brewing a Christmas spiced ale and would like to add a cherry Flavour.
Has anyone used the fruit syrups found in the polish shops? Am wondering if the sugar in them would restart fermentation.

[Dracusse]

Used couple of times .. it is restarts you fermentation ..  if you want to use it at bottling you have to count sugar content  to use it as primer