Okay, so, like, there's been a billion things going on, what with new job, new location, trying to sell house, trying to keep nose above water...It's been interesting. And I should probably write it up. However, this post actually is about yogurt o_o
I've been experimenting with homemade yogurt since the move to Boston - my office is right next to the kitchen, which makes cooking much easier than in the old house. And since apparently several folks have been inquiring about the homemade yogurt process, I'm putting it here for any interested for easy linking! Without further ado:
Fresh Crock-Pot Yogurt
There seem to be about as many different ways to make yogurt as there are people - since it's roughly as old as civilization itself, this really isn't surprising. The process below, arrived at through some experimentation, seems to be both easy for the busy geek, and pretty foolproof.
- Crock Pot (4-quart)
- A large towel, blanket, electric blanket, or heating pad
- A temperature probe (strongly recommended)
- A colander with a large coffee filter or cheesecloth (if making strained/Greek yogurt)
- 2 quarts (1/2 gal) of high-quality 1% milk (seems to be more predictable than skim or whole)
- 1/2 cup of powdered lowfat milk
- 1/2 cup of plain yogurt with active (important!) cultures
- Add the 2 quarts of milk to the crock pot. Whisk in the 1/2 cup of powdered milk.
- Put the lid on, and start the crock pot. You're aiming for 160-180 degrees, so you'll have to experiment with your pot to see what setting gets you there. I recommend sticking with the 'low' setting, if possible, it'll take a little longer but much less chance of burning anything.
- Let the milk heat until it reaches 160-180. You want it above 160 for at least 10 minutes, or pretty much as soon as it hits 180.
- Once the target temperature is reached, remove the crock-part of the crock pot, and place it in a sink full of cold water, up to about an inch below the rim of the crock. This assumes your crock pot crock can be removed like this - most can. Do not put the pluggy-in part of the crock pot in a full sink, unless you want us to read about you on a website with 'fail' or 'darwin' in the URL
- Stirring regularly, monitor the temperature of the scalded milk. You want to take it out of the water about when it hits 120. This shouldn't take very long - 15-20 minutes tops.
- Remove the crock from the water, and set on the counter. It should keep coming down in temp fairly quickly for a bit after you remove it.
- When it reaches 110-115 degrees, remove 1 cup of the hot milk, and pour it into a small mixing bowl with the 1/2 cup of pre-existing active yogurt. Whisk thoroughly, then pour it back into the crock.
- Lid the crock, and wrap it up fully to incubate. I've been wrapping it with an electric blanket on medium heat, which turns off after 3 hours. A large bath towel should work just as well, especially if you warm it briefly in the dryer first. Incubation time is up to you - probably no less than 4 hours, and not much more than 12. I tend to go with 8-9. You can do this right out on the counter, the crock and towel/blanket should keep the temperature more than happy for the critical first couple hours.
Once incubation is done, you'll have yogurt. It should smell quite sour/tart, but not spoiled. You'll see a lot of clear/yellowish liquid, too - that's normal, it's the whey. Just stir everything together, move to resealable containers, and let set for at least 8 hours in the fridge. After that, stir, add fruit/granola/sweetener/etc to taste, and enjoy!
Taking It Further - Strained/Greek Style
If you stop at the step above, your yogurt will likely be a bit runnier than store-bought after stirring. This is normal, since it has none of the thickeners of store-bought. If you prefer a thicker, Greek-style yogurt (think the consistency of whipped cream cheese), you just need to strain out the whey. Put a coffee filter or some cheesecloth in your colander, set that over a bowl in the fridge, and fill it with the well-stirred yogurt (after setting). Let it sit for a couple hours like that. The yogurt in the filter will thicken dramatically, and the bowl will fill with whey. Just spoon the now-thicker yogurt back into a new container. And keep the whey! It's full of good carbs, protein and vitamins, and is great as a water-replacement in baking (or making ricotta cheese, if you're feeling adventurous).
Hints for your Starter
The most important ingredient to a successful batch is the existing, live yogurt. If you're getting store-bought, you need to grab plain yogurt that says "Contains active cultures." If it just says "Made with active cultures" or something similar, well - that seems to be the yogurt equivalent of "Process Cheese Food Product". Not gonna work for culturing.
It's easy once you've got regular batches going; you just save the last 1/2 cup from one batch to start the next. Perpetual motion yogurt machine! But for your first batch, or if your culture goes 'off', you need store-bought to start with. The organic, plain yogurt from Trader Joe's is surprisingly cheap (for organic), and works really well if you have a TJ's near you.
One more hint - a starter also works after being frozen! After buying your first quart of 'starter' yogurt, set aside 1/2 cup for the first batch, and freeze the rest in ice cube trays. Once thoroughly frozen, dunk the tray in hot water briefly to loosen the cubes, and empty 'em into a ziploc. Just keep in the freezer til needed. When you need a fresh culture, set 3-4 cubes in a covered bowl on the counter when you start Step 1 of the process. By the time the milk's been heated and cooled, the frozen yogurt should be melted and ready to mix in as normal.
Okay, yeah, this all leads to delicious, natural, healthy, homemade yogurt, quite well and good. But how much does it cost compared to store-bought? I ran some numbers - prices may differ based on where you shop, your preferred brand/style, and what you use for your yogurt batches, but this was based on an average for what I could find.
Cost of ingredients
Roughly $3.50/gallon for basic high-quality milk (not the fanciest organic grass fed raw milk one might find, but a good, local dairy, for example).
Regular style: $0.90/quart (roughly $0.17 per 6-oz serving)
Greek style: Depends on how well you strain, but about $1.40/quart (roughly $0.25 per 6-oz serving)
$2-$2.50/quart for non-organic regular style (roughly $0.40 per 6-oz serving)
$3-$3.50/quart for organic regular-style (roughly $0.60 per 6-oz serving)
$6-$7/quart for Greek-style (roughly $1.25 per 6-oz serving)
I'd call that worth the investment, if you're a regular yogurt-consumer!