How to Make Yogurt

My husband calls me a tree hugger when I make yogurt.  He says I'm a 'granola' and an 'earth mother.'  He asks if I'm going to stop shaving my armpits.  Ew.  For the record, I'm not.  Even though I'm not total Nature Lady, I did make the switch from buying yogurt to making it because I started to feel bad about the ridiculous number of little plastic cups I was throwing away every month.  Just so you don't think I'm entirely altruistic, though, I made the switch for budgetary reasons, too.  Yogurt gets expensive, particularly if you like Greek yogurt.  And I do.  One gallon of skim milk results in about eight cups of Greek yogurt, or I could pay around $1.25 per 6 oz. container at the grocery store.  

I can't take any credit for coming up with how to make yogurt.  Annie over at Annie's Eats got me started down this path.  Her blog is awesome, but when I started making yogurt from her recipe I longed for more pictures to show me if what I was coming up with was anything like what she came up with.  After a lot of trial and error, I've come up with my own tricks to get my yogurt to turn out.  I thought I'd pass them along.  Or you could follow Annie's directions, because she's fab.

First, let me warn you that this isn't a fast process.  Allow at least 15 hours from start to finish.  I always start mine on a Friday or Saturday evening, because it needs to sit in the oven for 12 hours, and then it needs to be strained and beaten after that.  I don't have time to do that on a morning when I'm also getting four kids ready for school, and me ready for work by 7:40 am.  So here goes. 

I like to let my gallon of skim milk sit out on the counter for a while to bring it closer to room temperature.  Then I pour it into a pot.  Go with the heaviest pot you have.  For the record, this isn't my heaviest pot, but I was using that to make soup so I had to go with this one.  

On medium-low heat, bring the milk slowly up to 180 degrees.  This part may result in crud forming on the bottom of your pot.  I haven't figured out how to prevent this.  I'm convinced I need a LeCreuset pot, but I can't quite bite the bullet and splurge on one yet.  Maybe this year.  In any case, the best I've got for you is to whisk the milk quite often, and don't try to heat it up too quickly.

UPDATE:  This process goes way faster, and results in absolutely no crud, if you heat your milk in a glass container in the microwave.  In my four-cup glass measuring cup I can bring milk to 180 in 6.5 to 7 minutes.  That means a half gallon takes me less than 15 minutes to heat with far less mess than heating the milk in a pot.  However, I'm aware that some of my friends have a strong aversion to the microwave.  Both ways work, so go with whatever makes you happy.

Generally I would recommend using a candy thermometer, but my husband recently put ours in the dishwasher.  I used a digital meat thermometer because it was what I had.  Use whatever works for you.  Once the milk reaches 180 degrees, remove it from the heat and let it cool back down to between 110 and 118 degrees.  There are some chemistry reasons for this, but I'm not going to go into them.  Just trust me.  The 110-118 is super important, because if it's hotter you'll kill the good bacteria in your yogurt starter, and if it's cooler they won't multiply.

The cooling down takes a lot longer than you think.  I've tried all sorts of things to speed up the cool down, but I've learned to just put it aside and leave the kitchen to do something else for a while so I'm not too antsy.  When it has cooled down, I always pour the milk into a covered ceramic container.  I have tried to just keep it in the pot, but that doesn't work for me.  Not sure why--maybe something with the metal?  I've started using the dish part of my crockpot (it removes from the heater base) and it works better than anything else I've tried.

Now you need some yogurt purchased from the store.  That's going to get the good bacteria in there.  I use about a half cup, but I have to fess up about not being particularly exact.

Warm up your oven just a little bit--not so it's hot, just so it's a little warm.  Annie recommends turning it on for a minute, then turning it off.  I had baked Irish brown bread before I started making yogurt, so my oven was already warm.  This is going to seem weird, but wrap the container in a towel to help the container stay warm and, this is really important, turn on the oven light.  Then close the oven door and let it sit in there for 12 hours.  Annie says 8 to 12, but if I don't leave mine in there for a full 12 hours it doesn't come out well.

  
It's going to look kind of gross when it comes out.

You should notice that it's still quite warm.  I tested mine with my handy dandy meat thermometer, and it was still 118 degrees a full 12 hours later.

You could strain it now, but I've found my yogurt firms up WAY better if I wait until it's cold before I strain.  Since it's winter here in Iowa, I just set my container outside for an hour or two.

UPDATE:  If you have farm cats, they may eventually catch onto the fact that there is a dairy product under the lid and destroy your hard work.  In which case, putting this into the fridge instead of on the porch is a good idea.  Just sayin.

Now you're going to need some high tech tools to strain it.  Or not.  I like to use two steamer inserts to an aluminum pot I have, and cheesecloth.  Unfortunately I was out of cheesecloth this morning so I used paper towels instead.  Cheesecloth works better, but paper towels work in a pinch.  

 

Since the purpose of straining is to get rid of excess whey, I put the whole thing in my sink so it can just drain.  You can use whatever system you want.

Until I started using the crockpot, waiting 12 hours, and cooling before straining, I always had a LOT of whey and some yogurt.  Now it's the opposite.  I drain what I can of the whey first, and then I use a big spoon that has holes in it to scoop out the yogurt and put it onto the paper towels.

 
Let the yogurt strain until it is as thick as you would like.  This is the part that changes it from just yogurt to Greek yogurt.  I've waited a half hour, and I've waited hours.  I have found if I let it strain for too long it gets too thick--almost the consistency of a soft cheese--so I go with about an hour.  When I use cheesecloth I like to use a spoon half-way through the straining time to scrape the yogurt off the bottom and move it to the top because that seems to get rid of the whey from the top better.  That part doesn't work as well with paper towels.  When it's done straining you could put it into containers, but I don't like the texture of it--it's not smooth.  It's also not sweetened at all.  

You can flavor your yogurt however you would like, or leave it plain, but I like to use between 6 and 8 teaspoons of Stevia and about a tablespoon of pure vanilla.  I put it into a blender, and it morphs into the smooth, creamy consistency of the Greek yogurt you can buy in the store.  

Here's the save-the-Earth part.  Pour the yogurt into glass dishes.  Mine are Pyrex containers I picked up at a local WalMart.  

You can dress up your yogurt however you'd like.  I love to put about a quarter cup of frozen cherries in a container of yogurt in the morning, then take it to work and put it in my mini fridge.  By 2 pm the cherries are thawed and release their juice into the yogurt when I stir it around.  Frozen blueberries do the same.  I've also been known to put about a tablespoon of my homemade strawberry-rhubarb jam or peach jam into the container to swirl it around.

Total heaven.  See the green grass in that picture?  I took it late last summer when I made those jams.  I miss summer.  Sigh.  But the jam still tastes like summer, which makes my yogurt extra scrumptious.  

I'm not Nature Lady, and I do shave my armpits, but with this yogurt easily accessible in my fridge, I no longer contribute hundreds of plastic containers to landfills and I save money.  And I get to make food where I know exactly everything inside of it.  I have to feel good about that.  Try it.  It's FUN!