This type of salt solution is used to restore balance and add soluble calcium back into the milk after it has been pasteurised and homogenised. Without calcium chloride the coagulation action is much slower with these types of milk, so adding it sets a much firmer curd. It is typically mixed at the rate of 1/2 teaspoon (2.5ml) into 60ml (1/4 cup) of non-chlorinated water (per 8 litres of milk) and added to the milk just before the starter culture.
If using calcium chloride with dropper cap, you only need to add 3 drops per litre of milk if making yoghurt or soft cheese.
Speaking from experience, if you are using vegetable rennet, and are concerned about the quality of your store bought milk or using goat’s milk, I recommend adding calcium chloride. It will avoid a disappointing curd structure.
Calcium Chloride is a liquid that is stored in the refrigerator.