Danisco (DCU is Danisco Culture Unit) is sold in sachets that are not fixed weights. The amount of culture is defined by activity. To use them you need to know:
1. How many units per how many litres of milk (i.e. 1 unit does 1000L milk)? Check Fromagex's website for cut sheets.
2. How many units are in the sachet you bought?
You must dump out the contents of the sachet and weigh it. Then take the total weight, divide by the numeb of units and voila, you have the weight of culture per unit. Divide by any fraction for the quantity of milk you are using. This will give you consistant acidification.