Friday, August 22, 2014

How to Make Greek Yogurt

Retirement has brought me more time to do things that I always thought that I'd never have the time for.  I've always wanted to try my hand at making Greek yogurt.  It turns out that it's fairly easy, so easy that even I can do it. The first thing you need to make Greek yogurt is yogurt.  You can either buy plain yogurt or make your own. Not only making yogurt at home cheaper than store bought but read the label on the stuff from the store and depending on the brand you'll find sugar, thickeners (because starch is cheaper than milk) and a science fair full of chemicals. Homemade yogurt contains milk and some special bacteria and that's about it.

To make yogurt from scratch take the store bought milk of your choice (skim, 2%, full or even goat milk).  The higher the fat content the smoother and creamier your finished yogurt will be) and slowly heat in pan, pot or microwave until the temperature of the milk reaches 183F.  Keep stirring as you heat or the milk will burn onto the bottom of your vessel.  I use an electronic thermometer with a probe.  Heating the milk kills off any bacteria in the milk and makes it an ideal growth medium for the yogurt bacteria that you'll stir in later.

I've read that there are lots of variations on this theme and they all work.  The milk can be heated in a microwave oven and yogurt can be made in a crock pot and even in a rice cooker, anything that will hold the constant temperature that the yogurt bacteria requires to prosper in your milk.

Once the milk reaches the desired temperature let it cool until it reaches 110F, then stir in a dollop of yogurt.  The yogurt bacteria is alive and you're going to introduce it to the warm milk to let it grow in and colonize the milk.

Next to the yogurt I make I favor Fage
Stir in and dissolve some store bought yogurt into your now cooled to 110F milk and then move to plastic containers.  For the next 10 hours or so the idea will be to keep the milk warm so that the stirred in store bought yogurt can colonize it.  Too hot and the yogurt bacteria dies, too cool and the yogurt bacteria goes to sleep and either way you'll just wind up with spoiled milk.  110F is just right but that temperature has to be maintained.  I put my budding yogurt crop into the oven to incubate.

2 containers of yogurt to be
Why the oven?  The oven is insulated so it'll hold heat.  I preheat the oven to around 110F and keep my eye on the temperature during the day thanks to a laser thermometer.  The brown rectangle on the bottom of the oven in the picture above is a pizza stone, it'll hold on to some of that heat.  Bonus yogurt making points if you have an older oven with a pilot light.  You also swaddle the plastic containers in a blanket or a towel to hold in the heat.  After 10 hours of incubation remove the yogurt from the oven and refrigerate overnight and prepare to be Greeked.  

The next morning......

It's yogurt!
Time to put the Greek into the yogurt.  In order to Greek the yogurt you have to strain out the whey.   I use a fine mesh strainer sitting over a small pot to catch the drained whey.

Before yogurt
Add yogurt and wait for the whey to strain out.
Draining a-whey
I also use several permanent #4 coffee filters (Gold Tone) to drain yogurt.

Empty Gold Tone filter
Gold Tone filters getting the whey out of my way
Cover the straining yogurt and refrigerate.  The longer the yogurt drains the thicker the Greeked yogurt left behind in the strainer or filter, 5 hours usually gives me the thickness I like.

Optional: add fruit, flavorings and sweetening to taste.  Enjoy!