Lactose bag 1kg

Lactose is a non-fermentable sugar and therefore leaves a residual sweetness after fermentation is complete.
Lactose (milk sugar) is used in Milk Stouts and other beers where more sweetness is desired.

Lactose affects the gravity measurement and gives a higher OG, as well as a higher FG.
It is normally added towards the end of the cooking time. 

3g per liter increases FG by about 1 point (1.001)