I like yogurt, but not all the time, so I generally only need to make a large batch every 3-4 weeks. Since my overhead cost at this point is ridiculously low -price of a gallon of milk, occasionally vanilla extract and sugar if I'm looking to make vanilla yogurt- it's also a great way to help keep my grocery bills down. I like to bring yogurt with me to work as it is easy to store and tastes great.
You will need:
-large mouth Mason/Ball canning jars
-a large stock or cooking pot
-kitchen thermometer
-cooler or ice-chest
-gallon (or half-gallon) of milk
-yogurt starter or culture to kick off the process
Optional:
-vanilla extract
-sugar
Simplified, the process heats milk, cools it down, adds a previously prepared yogurt culture, then incubates for 4 hours or more. I generally start by cleaning or sterilizing my jars. I've boiled them in hot first and just plain washed with hot soapy water; both methods seem to work the same. If you feel more comfortable, you can always boil them first.
Once the jars are cleaned out and ready to go, I begin to heat approx. 1 gallon of milk (I generally use 2% milk....I've used whole milk, 1%, 2%, and skim. whole milk yields the thickest and creamiest yogurt as it has the highest percentage of milk fat...roughly 3% I think. skim milk will set but be runnier than the others. 2% is a good balance) and also fill a kettle and start boiling the water simultaneously. The hot water will be used for the incubation in the cooler later on.
You want to gradually heat the milk to 185-195 degrees F. I don't own a ceramic or cast iron stock pot, so I continually stir my milk with a whisk to ensure it doesn't burn and stick to the bottom of the pot.
Once the water boils, I pour it into the cooler. I then add about a half gallon of cold water to bring the overall temperature of the water to 120 degrees F. Once the water reaches about 125-130, I close the lid to keep the water hot while I finish prepping the milk.
Once the milk reaches 195 F, turn off the stove. You will need to cool the milk to approximately 120 F. The easiest way to do this is to use a water bath: fill your sink about half-way with cold water, place the pot in the water and monitor with thermometer until temp is cool enough. This generally takes about 15 minutes or so.
You can strain the milk skin that forms if you want. There may be more or less depending on the richness of the milk. If you use whole or 2% milk, there will be more skin than if you were to use 1% or skim. This is normal. Once the milk has cooled sufficiently, you need to add your yogurt starter. All yogurt has active enzymes in it. I generally don't go with a specific brand but check the ingredients first to see which has a higher number of active cultures. The more cultures in the yogurt, the faster it will turn your heated milk into yogurt.
You may have different brands depending on where you live in the U.S. Make sure it has several cultures and always buy plain yogurt. You can add sugar later.
Take about a cup of the plain yogurt and add to your milk. Make sure you mix it thoroughly and completely. I use a whisk to do this portion. If you already have yogurt made up, you can use some of that. If this is your first time, you will need your own store-bought starter first. (This is also where those optional ingredients come into play. If you vanilla yogurt, you can add vanilla extract and sugar during this step of the process. How much depends on personal preference. I don't really measure anymore, but for a gallon of milk, you will need several TBSP of vanilla to flavor the entire batch. I have used between 1/2 c. of sugar and 1c. of sugar. Both are fine. If you are really watching your calories, skip the sugar and use fruit instead. DON'T get clever like me and use brown sugar. I tried that once thinking it would make a better flavor or be slightly healthier....the molasses in the brown sugar made my yogurt thick, syrupy, and stringy. It was awful!!
Once your yogurt culture is thoroughly mixed into the milk, you will need to pour into the jars. I find that a full gallon always makes just a bit too much, so I leave a little in the milk jug so I always have enough space in my canning jars. Thefrugalgirl recommends the wide mouth jars since they are easier to scoop out of with a spoon. Great tip!
Then the easy part: you get to leave the jars in the closed cooler for 4 hours. You don't have to do anything...you don't check on the jars, don't have to open the lid, nothing. Just go about your business and let them sit undisturbed for a minimum of 4 hours. I have left yogurt in the cooler overnight and then put them in the fridge in the morning with no problems. Thankfully yogurt-making isn't an exact science.
Roughly 4 hours later, you shall have yogurt! Once they have finished incubating, all you need to do is transfer the jars to your fridge. They will firm up overnight and you can eat it the next morning.
This was from an older batch made with 1% milk. My yogurt I finished making this afternoon will have a slightly firmer appearance.
Yum! Homemade yogurt and granola. Super easy and super cheap.
Good luck! I have done this now for about 6-7 different batches of yogurt, and other than the brown sugar fiasco, they've all turned out great. I remember being super paranoid/nervous the first couple times, but it's not difficult. Like most things, there will always be a bit of trial and error, but fortunately the process is forgiving. It's ok if you heat the milk to 190F instead of 195 and its ok if you leave it in the cooler overnight. In the end, you're still saving money and have a nifty new skill. :)
