I mean, really. It's so easy it will change your life forever.
And it will save you a stinking butt load of money if you like Greek yogurt. For $2 (TWO DOLLARS!) I got no less than 10 cups (TEN CUPS!) Greek yogurt--that's $.20/cup if you're math impaired (don't worry--math unnecessary for this recipe; brains in general unnecessary for this recipe). Twenty cents for creamy, perfect Greek yogurt.
You can eat it with anything. I like it for breakfast with some jam mixed it. My kids like it best blended with jam and put into popsicle molds and frozen. My friend serves it as a dessert. She mixes it with jam and then adds a squirt of whipped cream to the top. But don't think it can only be served sweet. This thick Greek yogurt can be used as a substitute for sour cream and cream cheese. It can be used in savory dips, for ranch dressing, with tacos.
And in case you missed the whole Greek yogurt bandwagon (or were maybe too poor to buy a ticket), Greek yogurt is awesome and loveable because it is a) delicious and creamy, b) higher in protein, lower in sugar (lactose), and lower than sodium than regular yogurt. And did I mention creamy awesomeness? It's also just way versatile--it can really be subbed for a lot of things.
Let me say that making yogurt is not entirely new to me. I even have a yogurt maker (which I may now sell) that has cute little cups with lids. I used it faithfully when we lived in California, but when we moved here, it became cost INeffective. I couldn't find small amounts of plain yogurt and after I'd bought 32 oz of plain yogurt, well then it seemed silly to bother making little cupfuls of yogurt. And my homemade yogurt always came out somewhat runny. This is true of yogurt. Most (if not all) of what we find in the store has been artificially thickened--cornstarch and gluten are both in Dannon. Homemade yogurt tends to be thinner. Real Greek yogurt, on the other hand, is thick because much of the whey has been strained out of it. But because of that, it is often very expensive. Thus, for the last several years I haven't made my yogurt; I've just bought it. Until the fateful day when my friend (the dessert yogurt making one) brought over some yogurt with raspberry jam in it. It was better than ice cream. Oh, yes, it was. Thick, creamy, and beautiful. And it had cost her almost nothing. And it had been stupidly easy. Now that's what I'm talking about. Because many of the other homemade yogurt recipes I knew of (the ones without the handy yogurt-maker) seemed hard. There seemed to be lots of variables that could cause it to fail. Some required you to double boil your milk (I double boil nothing, people, nothing). Some gave detailed instructions for putting it in a cooler or oven and then keeping it consistently warm but not hot. If you got too cool or too hot, you'd wind up with curdled, runny nasties instead of yogurt. Yes, it was all too frightening. I needed fail proof. I needed dummy proof. I needed distracted mom proof. My friend provided that.
She had used a pot to make the yogurt. You can too if you don't have a crock pot. A regular pot works great, but it requires more of your attention. A crock pot, on the other hand, requires only a one-minute attention span and perhaps and IQ of 32 or so.
Now, what do you do? Let me pull back the curtain so you can be amazed.
1. Put 1 gallon whole milk into your crock pot. Put lid on. Heat until 180 degrees. This should take between two and four hours (depending on your crock pot). If you don't have a thermometer (though one is useful), it will be bubbly/foamy all over on top without actually boiling.
2. Remove lid and let cool to 110-115 degrees (if you don't have a thermometer, this will feel warm when you stick your finger in, but not hot--this is the temperature you'd kind of want to get baby formula to--warm, but nothing that would scald a baby's throat).
3. Add 1/2 C PLAIN yogurt and whisk it in. (I add yogurt to a small amount of milk and whisk in order to keep it from lumping up. Then I put that into the big pot of milk and whisk.)
4. Put lid back on.
5. Put crock pot in oven for 6-8 hours. You don't have to heat your oven or leave the oven light on. You don't have to do ANYTHING. The crock pot provides natural insulation, so it doesn't cool too quickly and the oven provides a space to trap the necessary warmth for your yogurt to yogurtify (it should be kept at a fairly stable 110 degrees; it does this naturally in a crock pot in the oven, so don't worry). That said, I would not recommend you put it into a cold oven (not a problem for us in the summer, but in winter it gets chilly around here). If your oven is cold, turn it on for 1 minute BEFORE you put the yogurt in. Then turn it off. Then put the yogurt in. (Ah, now the IQ requirements have moved up to 45). It will need 6-8 hours to yogurtify. It's nice if you can time this overnight. If you do it during the day, you may want to put a little post it note on your oven that says, "Do not turn on." I do this (yes, I do) because if you or someone you love comes in and decides to make cookies and pre-heats the oven before realizing there's yogurt in there, your yogurt will be ruined and you will be sad.
6. When you take it out, you'll have regular yogurt. Reserve 1/2 C of this for your next batch of yogurt and put that 1/2 C in the fridge.
(It will look like this.)
7. Now: You can eat the rest of the yogurt regular-style if you want (it was actually a little thicker than that which my yogurt maker used to make). But I HIGHLY recommend straining it and making Greek yogurt (because it's awesome, that's why). Get a tea towel. Put it over a colander, and strain your yogurt. You can do this in the sink if you don't want the whey. Or you can strain it over a pan or large pot/bowl if you want the whey (Note: Whey can be used as a milk or buttermilk substitute in some recipes. It works well in muffins and things like that. That said, I throw my whey away most of the time (unless I know I'm making muffins or something soon). Lazy, I know. Straining will take between two and six hours depending on how thick you want your yogurt. I like mine thick. You might give it a stir after 2 hours to get it to strain more quickly.
And you're done. You will have a TON of Greek yogurt. In Evansville, we can currently get milk for $1.69 at Aldi. And then you'll need a bit of plain yogurt as a starter. Greek yogurt from the store occasionally goes on sale for $1.00/6 oz., but is usually much more. The nice brands can cost as much as $5.00(ish) for 16 oz. or so.
Now to answer some questions:
1. Do I need an instant read thermometer? No, but it is helpful; it takes any and all guesswork away from the process. And you will pretty much earn back the cost of your $9 thermometer in the first yogurt making, so it's a reasonable purchase. Still you don't have to have one. You just might need an IQ slightly higher than 32.
2. What will I do with all that yogurt? The sky is the limit. If you make this stuff, you can stop buying yogurt, sour cream, and (in some cases) cream cheese. You can make amazing smoothies and popsicles. You can do tons of stuff with it.
3. Do I have to use whole milk? Probably not, but I always do. Still, I'm pretty sure you can make it with any type of cow's milk . However, I won't vouch for taste. True Greek yogurt is whole fat. It's only us Americans who've freaked out about that and developed lower fat versions. It is my opinion that skim Greek yogurt isn't really Greek yogurt at all. It is skim, strained yogurt. Eat it if you want. But my other opinion is that fat (without a lot of sugar) is NOT the enemy. I think natural fats are healthy and filling and great.
4. Why do I heat it and then let it cool? I don't have a complete scientific answer for you. All I know is that if you heat it to 180 you wind up with thicker yogurt than if you don't. I imagine you don't have to heat it that much. I know there are even raw yogurt recipes out there. You'll just likely end up with thinner yogurt. Of course, you'll be straining it, so will still end up with thick Greek yogurt--you'll just have a bit less of it because more will have strained out.
5. How do I make it on the stove top? Let's say you don't have a crock pot. You can still make this stove top. It's best to do when you have other jobs to do in the kitchen because it takes a while to heat and needs to be stirred occasionally so you don't want to burn on the bottom. (You can cook it faster, but you'll have to stir frequently or even constantly so it doesn't burn on the bottom.) Also, you'll want to make it in a heavy pot. The time I made it on the stove top, I used a porcelain-covered Dutch oven pot (WITH A LID). You need to do this because when you put it in the oven, it needs a sort of heat-holding pot. Otherwise it will cool too quickly and not set properly. I suppose you could use a normal pot and insulate it with towels or something, but for me the IQ requirements and fail factor get too high with that.
6. Can I make less? Probably. The problem you're going to come up against with this no fail method is that if you only have a little milk/yogurt in your pot, it will cool off faster. If it cools off too fast in your oven, you'll wind up with runny, curdled mess, not yogurt. If you really really want to make less, I recommend putting it in a small cooler instead of an oven. Or you might just have to babysit your oven a bit more and turn it on here or there throughout the setting process to ensure that your yogurt doesn't get too cool. Anyway, I'd really encourage you to make more simply because yogurt lasts a long time, which leads to...
7. How long does it last? I don't know. Ha. Because it's never gone bad on us and we've kept it in the fridge for upwards of two weeks. I imagine it would last a good month, maybe two, but can't promise that. I will try to do a little experiment next time I make yogurt and set some aside and see how long it takes for it to go bad.