In New Zealand milk is a relatively expensive staple to buy. With our 2 growing boys and a DH that loves milk, not to mention my countless coffees during the day we go through a lot of milk. Anywhere between 9 and 12 litres a week.
So there are a few tricks I have learnt along the way so you don't have to buy as much.
The first tip is with your bottle of milk, buy dark blue or full cream. Bear with me if you are a light blue drinker or low-fat drinker, I am myself.
Either remove 1/3 of the bottle into another bottle and dilute it also using the 1/3 ratio, or just use this as normal until you have used 1/3 of the milk from the bottle. Now take your bottle and top it up to the top with cold water. That is all you need to do. You instantly have a full bottle of milk again. Give it a shake. This tip has come via the grapevine from somebody in the dairy producing industry. We do it here and have had no problems, you can't notice the difference in taste, i.e it certainly does not taste watery. We can now buy less milk, fantastic! In fact I am trying to push the envelope a further with the milk and water it down even more.
The second tip, is use milk powder in your cooking. If you are not already doing this and are on a budget and looking to live frugally start doing it. You cannot notice the difference when you use it in baking and bread making. I buy Full Cream Milk Powder and water it down further than the instructions to make it stretch. We were making it up regularly either as we were baking or keeping a little bit on hand in the fridge. I use it so often that I now just keep 2 litres of it made up in the fridge in an old milk bottle I have re-used. It is slightly cheaper per litre to use milk from milk powder, that means you can keep the 'real' milk for drinking and breakfasts.
In NZ I have made cost comparisons between Pam's and Homebrand Milk Powder. I haven't dreamed of using Anchor or any of the more premium brands as they are far to expensive. The cost comparison is from our local Pak N Save and Countdown supermarkets. I urge you to look around at the options available to you, when you break it down into how much per litre, you may be surprised at what each item/brand costs - I was.
The cheapest way to go here is using the Homebrand Milk Powder in the 1kg bag - it works out to be $1.39 per litre, Pam's Milk Powder is $1.63 per litre, unless it's on special and then its 0.04cents cheaper than Homebrand. As for the cost of 'real' milk, we use Budget and get it in the 3 litre containers, this costs $1.82 per litre. So as you can see it's more cost effective to supplement in your baking with milk made up with milk powder. I think I may even look to the local dairy today and see what they have in the way of buy 2 bottles of Dairy Dale etc for x amount of dollars, it could work out cheaper per litre still.
The third tip is if you make your own yoghurt and cheese like we do, drain off the whey by sitting your yoghurt in a strainer and cheesecloth or similar for a short period of time. This will also thicken the yoghurt. Then use the whey instead of milk when you are making muffins and cakes etc.
I'd love to hear if anyone else has any milk saving or extending tips!