Can Condensed Milk

1 1/2 cups whole milk
1/2 or 2/3 cup unrefined sugar (organic cane sugar, evensucanat depending on your final goal for the condensed milk)
3 Tbs butter
1 tsp vanilla

Method:

Mix sugar and milk together in a heavy-bottomed saucepan. Stirring often, bring to a low simmer over medium-low heat. As soon as steam starts lifting off the milk, lower the heat even further, and when the sugar is entirely dissolved, put the heat as low as it can go. A simmer burner is great for this.

The goal is to reduce the quantity in the pot (which is now about 1 3/4 cups) by approximately half. It takes about 2 hours at very low heat to reduce to one cup of liquid. You could speed it up a bit if you watch carefully and stir often. I preferred the freedom to wander the house doing other tasks, and thus allowed my process to take quite some time.

Once reduced to your satisfaction, whisk in the butter and vanilla. The recipe is equivalent to just less than one whole can of brand name sweetened condensed milk. (One can = 14 ounces, which is 2 ounces shy of 2 cups. by weight, oops! The can is equal to 1 1/4 cups liquid. Substitute tables for homemade condensed milk vary from 1 1/4 cups all the way to 2 cups. Use your judgment!)

Depending on what final product your sweetened condensed milk will be used in, you will probably need to allow the mixture to cool considerably before using.

One other option for a homemade sweetened condensed milk is to add 1/2 or 2/3 cup unrefined sugar to a can of evaporated milk. You may need to heat to fully dissolve. However, you still have to deal with the unhealthy can lining and whatever over-processing makes the milk shelf stable.