Upon moving to Denver, I discovered that out here, milk is dirt cheap compared to PA (despite PA's abundance of cows). At under $2/gallon, it's definitely worthwhile to make my own yogurt! I first tried it before traveling to West Africa for 3 weeks last summer and realized how incredibly easy it is. It does take time, but making your own yogurt is simple, fun and tasty.
In a nutshell:
- Heat milk to 180 F (ish - hot but not boiling)
- Cool to 110 F (ish - still warm, but doesn't hurt your finger)
- Whisk in starter - some plain yogurt or freeze-dried starter
- Pour into glass containers
- Stick somewhere slightly warm and forget about it for 6-8 hours or overnight.
- Remember about it, discover you've made yogurt, and enjoy! (well, maybe refrigerate first...)
1. Heat milk to 180 F (ish)
2. Cool to 110 F (ish - still warm, but doesn't hurt your finger)
Again, I use a thermometer, but I've done it without. When it feels "lukewarm" (like, if your coffee got this temperature you'd microwave it or throw it out), it's ready.
3. Whisk in starter - some plain yogurt or freeze-dried starter
You can use it, but I haven't had great luck with store-bought yogurt as a starter. I use YoGourmet starter, from a natural foods store/aisle. It's usually refrigerated near the yogurt, if you're looking for it. Once you've made a batch, though, you can use that yogurt as a starter, and keep the rest of your purchased starter for several batches from now. Supposedly the yogurt cultures eventually get a bit unbalanced and you should start from a fresh starter.
You can also freeze some yogurt in ~1/4 C batches to use later - that will keep your starter good longer, since each comes from the original batch. Doing this, one envelope of starter lasts me for 20 or so batches - freezing 5 starters, using them up then making 5 more from the last batch, etc. about 4 times before using a new envelope of starter.
4. Pour into glass containers
Rinse them well with hot water first to make sure you don't have other contaminants in them. I like to use jam-sized canning jars and make individual serving containers. If you don't fill them all the way, you'll have room to add some sugar or honey and some fresh cut fruit on top.
5. Stick somewhere slightly warm and forget about it for 6-8 hours or overnight.
I've seen a lot of suggestions for this, from an oven with pilot light on (gas oven) to just wrapping the already warm jars in thick blankets, to putting them in a cooler along with a few large containers of warm water. My personal favorite is to turn my oven on for a bit while I'm waiting for the milk to cool with a baking stone (or heavy ceramic casserole dish, etc.) in it. Then turn the oven off, but the heat from the stone will keep it slightly warm. You're going for around 80-90 F.
Even better is to make cookies in the oven first :) Then you have a pre-warmed stone and fresh cookies to boot!
Then just leave it be. In 6 or so hours, you will have yogurt! If you like it thicker, stronger flavored, or if you're lactose intolerant, leave it in for 8 or 10 hours or overnight. The longer it stays unrefrigerated, the longer the bacteria have to digest the sugars (lactose!) in the milk, producing the acid that turns your milk to yogurt. I nearly always leave mine overnight, and the last batch was in there a good 12 hours and still is great.
6. Remember about it, discover you've made yogurt, and enjoy! (well, maybe refrigerate first!)
Put some lids on and throw it in the fridge. Enjoy with sugar, honey, applesauce, fresh/canned/frozen fruit, even Nutella!
*Note: always mix in your extras after incubation. Yeasts and other bacteria from fruit can change how it works. Exception: I have tried adding some instant coffee and/or cocoa powder (sans sugar) before culturing the yogurt. I found it takes a bit longer to set, especially the coffee, but it does set, and tastes great! Add a spoonful of sugar before eating.... Yum yum :)