How to make expensive Greek yogurt for less than $5 a gallon

Greek yogurt has been all the rage for the past several years, and for good reason.  It's a power house of nutrition, especially protein.  If you factor in the additional benefits of probiotics (beneficial bacteria for your gut), Greek yogurt is a health bargain, even at full price.

But you can successfully make it for less than $5/gallon (your mileage may vary depending on that you are willing to pay for a gallon of milk).  Here in our home, we prefer "real" milk, purchased directly from the farmer. We have been consuming "real" dairy products since 1998, and have never, ever had a food borne illness from consuming non-pasteurized or non-homogenized milk products.  The concern is trumped up, but that's a different blog post.

To make your fancy yogurt you'll need a large slow cooker, a wooden spoon, approximately 1/2 cup of plain yogurt with live cultures (just about any commercial yogurt on the market and you can be as discriminating as you want), a gallon of milk, some cheesecloth to line your strainer, and a pot to catch the yellow liquid (called whey) that will drain off of the yogurt.

Pour your milk into your slow cooker.  Turn it on to "LOW" and allow to warm up for several hours until you see many tiny bubbles on the surface.  You do not want to boil your milk.  I have, in the past, accidentally overcooked the milk until it turns a light tan color.  It didn't affect the quality of my yogurt, it just looked bad to those in the family who prefer their milk "white".  Because there is no true standard amongst slow cooker temperatures, I cannot tell you how long your slow cooker might take to reach the tiny bubble stage, but mine took 3 hours to reach approximately 140F degrees on my digital thermometer.

I then turned off the heat and removed the lid to cool my milk to 110F degrees.  This took about two hours, and will vary depending on your room temperature.

When my milk reached 110F degrees, I added my 1/2 cup plain yogurt (I used Fage plain Greek).


Stir the yogurt in until completely dissolved.  Now your milk is ready to "incubate".  There are different methods to achieve this.  My inner crock from my slow cooker can be removed, so I take it out, put the lid on, and put in my unheated oven with the light on.  The light is sufficient to create just enough warmth to maintain the temperature at 101F degrees. The idea is to maintain the temperature between 100F and 110F degrees for at least six to ten hours, or until your yogurt is thick.  Another method is to set your pan or crock on a heating pad on the counter and wrap with a towel.

Your yogurt should thicken up nicely if kept in the correct temperature range. If it still has not thickened, cover it back up and continue to incubate it for several more hours.  Don't worry, there is a large margin of error before you could actually ruin the yogurt.

When your yogurt is thick, congratulations!  You now have yogurt!

But don't stop there, Greek yogurt requires a few more steps...

Line your strainer with cheesecloth and position over a pan large enough to catch the precious yellow liquid (called whey).  Pour your yogurt into the strainer and let sit for about an hour or more.  As the liquid whey drains off, your yogurt becomes even thicker.  If left to strain for days, it will eventually become a very soft, spreadable cheese, resembling cream cheese.  But if you stop the process after only straining for about an hour, you will have Greek yogurt at a fraction of the cost of store bought Greek yogurt.

Do not throw away the whey!  It's an excellent medium for soaking grains and flour or for adding to to baked goods for added nutrition.  I've also used whey to make dill pickles using a process called lacto-fermentation.  They were a big hit here in my home, and fermented foods will be a topic for another day.

This is the yellow liquid that was strained from my yogurt.  It's called "whey" and is packed full of nutrition.  Whey lasts a long time in the refrigerator without spoiling, and usually our demand is more than our supply.

A gallon of Greek yogurt barely lasts a week in our home as we use it to substitute for sour cream and I use it for baking.  Remember to save a half cup of your yogurt creation to use as a starter for your next batch!