Saturday, June 23, 2012

Experiment #10: Homemade Yogurt

So before I start, I apologize. I tried really hard to keep this one short. I mean, seriously. Yogurt is simple to make! But there’s just a lot of information about the art of yogurt making. Probably why the yogurt manual I have is 79 pages…Ok, enough rambling - enjoy!

Please circle the statement that is true. When you go to the pediatrician...
a. At least 10 nurses and the custodial staff know your children by name
b. The receptionist says, “Weren’t you just here yesterday? And last Friday? And the Wednesday before that?”
c. Your pediatrician says they are naming exam room 8 after you
d. The guy at the ticket booth in the parking ramp recognizes your car and takes a few hours off your ticket price because your visits have single handedly paid for the ramp resurfacing
e. All of the above

Guess which one my family would circle. Need a hint?

Largely thanks to Madeline and my post-surgery paranoia, in the 22 months we’ve been attending the University of Iowa Hospitals and Clinics, we have wracked up 66 office visits (including an embarrassing stinky visit), 20 phone calls to the nurse line, 15 days in the hospital, 7 x-rays, 4 ultrasounds, 3 ECHOs, and 2 ER visits. And that’s not even counting Nick and his quasi TB and possible Lyme disease (don't even ask). Yeah, that’s pretty ridiculous. 

Enter yogurt.


You see, at least a quarter of those visits, one ER trip and at least one prescription medication involve digestion issues and/or slow weight gain.

Probiotics (helpful bacteria found in yogurt) offer protection for your digestive system and help with digestion itself. Eating yogurt helps reestablish the healthy bacterial flora in your mouth and body and evidence suggests probiotics can treat certain digestive problems like irritable bowel syndrome and diarrhea, prevent exzema, help with colds and flu, and even treat oral thrush. Yogurt is also high in protein, calcium, vitamins D, B2 and B12, potassium and magnesium, which, as Nora will tell you, is good for healthy bones, strong muscles, not getting sick, and (snicker, snicker) healthy poops and pees.

Madeline (our teensy, weensy, slow growing one) has recently decided she only likes to eat yogurt, fruit, bread, yogurt, smoothies, pancakes, yogurt, chocolate yogurt and condiments (sour cream, ketchup and butter are her favorites). Oh, and yogurt.

So yogurt is important. It is also very expensive.

Last September, I spent $30 on a week’s worth of organic “gooberry pie” kefir (It's awesome - essentially liquid yogurt - usually tangier, with slightly different bacterial strains). I witnessed the incredible change in both girls’ digestive health and Madeline’s overall calorie intake, and realized how unsustainable this dietary solution would be for us financially. That same week, we got our new issue of the Food Network magazine with a recipe for homemade yogurt.

It was time.

I did lots of research. There were tons of different sites explaining how to make it. It was slightly overwhelming and for several days, I sat paralyzed by too much information. In the end, I just went with Melissa D’Arabian’s recipe from the food network magazine. Huge, smashing success!

Nora & Madeline's beautiful bathroom wall art.
So now, I'm creepily, obsessively addicted to making yogurt. I usually make at least a quart of yogurt each week (on good weeks I’ll make up to a gallon). My kitchen floor may be sticky, the walls covered with Picasso-esque chalkings, the laundry sits unfolded in baskets and the living room strewn with tiaras, bracelets, puzzle pieces and trains, but we eat homemade yogurt!

So here you go - the complete documentation of my journey. My flops, my successes, some hints and some recipes. Enjoy!

The Experiment
Time to Completion: 14 – 26 hours (depending on how tangy you want your yogurt) – about 30 minutes active.

Kids can help out with pouring, measuring, mixing, testing & eating!

Cost Comparison for making plain yogurt:
Store-bought yogurt – I’ve seen anywhere from $3 - $12 per quart (or 32 fluid ounces)
Homemade yogurt – Ranging from $1.25 - $3 per quart (depending on the type of milk and yogurt starter you purchase). You’ll be adding $.05 - $1.00 extra for thickeners and sweeteners (depending on what you use).

Measuring cups, measuring spoons, saucepan, stovetop, whisk, incubator (see below – I use a heating pad and a large metal bowl), large jar or glass bowl (must hold slightly more than a quart), plastic wrap or a clean kitchen towel, kitchen thermometer (technically this is optional, but I’d recommend spending the $5-10 to get one)
Milk, cream, thermometer and, the most essential, a little Michael Scott...
4 cups (1 qt) of milk
¼ cup of good quality yogurt with active cultures
Thickener (optional) – ¼ cup of nonfat dry milk or 2 tbsp tapioca starch
Sweetener (optional) – ¼ cup of maple syrup (I'd imagine you could also use sugar or honey, though I’ve never tried it) – more or less to taste
Flavoring (optional) – fruits, vanilla extract, chocolate, etc. (see variations below)

The Basics
Don’t be intimidated. It really is easy!! If what I wrote seems overwhelming, just use this recipe and come back here for more detailed explanations and hints. I like to be thorough so others can avoid my mistakes!

1. Pasteurize the milk. This makes sure you kill all the harmful bacteria. Pour 4 cups of milk into a saucepan over medium-low heat and, periodically whisking, bring the milk up to 185 degrees. (I’ve seen equally valid directions recommend anywhere from 160 – 185 degrees, but I’d rather err on the side of slightly too hot). If you don’t have a cooking thermometer, this is “scaldingyour milk – it should be steaming profusely, but not boiling. This usually takes me 10 – 20 minutes. 

2. Remove from heat and cool. Let the milk cool to around 110 degrees (the optimal temperature for bacterial growth. If you leave it too hot, you’ll kill the bacteria in your yogurt starter. The time this takes varies depending on the type of milk you use and if you added any thickeners. It usually takes me 20 – 40 minutes. **THIS IS A GOOD TIME TO STERILIZE WHATEVER CONTAINER YOU ARE USING TO “GROW” YOUR YOGURT IN. I usually fill the container with water and microwave it until the water is boiling. This way you make sure you’re just growing good bacteria.  Just make sure you let the container cool down enough before adding the milk & starter.

3. Add the starter. Here’s where you inoculate your milk with your new, good bacteria. Just dump and mix well. 

World's best incubator!
4. Incubate your milk. Put the milk in a glass container, cover with plastic wrap (poke holes in to vent) or a clean cloth, and place it in an “incubator.” They have yogurt makers you can buy that have the perfect temperature for making yogurt, but I created one of my own using a bowl and a heating pad. It works great and it was free (just make sure yours doesn’t have an automatic shut-off)! I’ve also read about making it using a slow cooker, an oven, and a cooler, although I haven’t tried any of these.  Check out a bunch of ideas here. Make sure you test the temperature of the heating pad (or whatever you are using) before incubating. It should keep your milk, undisturbed, at a relatively constant temperature between 90 – 112 degrees. Too cold, the bacteria won’t grow. Too hot, they’ll die (I’ve read that temperatures over 118 are lethal). It’s important you know approximately where your temperature falls in that range as that will greatly affect how long you incubate your milk – cooler temps will require longer incubation times. 

5. Check for the yogurt to have set (I feel this is optional). Depending on how warm your incubator is, your yogurt will have “set” (solidified) by 5 – 8 hrs. If I’m around, about 5 hours in, I’ll open it up and give the bowl a little jiggle to make sure everything is working. 

6. Remove the yogurt from the incubator. This is where you get to customize your yogurt - decide ahead of time how tangy and thick you want your yogurt. The longer it cultures, the tangier and thicker it will be (although let it go too long and you may actually kill off the bacteria because they’ve consumed all the food). I’ve let it culture anywhere from 7  - 24 hours (24 hrs was an accident - my default is 15 hours). **NOTE: After 5 hrs, you can taste the yogurt periodically to get a sense of tang, but you won’t be able to tell final texture until the yogurt has been in the fridge 6-8 hours. Make sure you use a CLEAN spoon each time or you’ll contaminate the yogurt.  

7. Stop the fermentation process. This needs to be a total of 8 hours. Pull the yogurt from the incubator and, for shorter culturing times, let it rest at room temperature for 2 hours, then transfer to the fridge for 6 hours. Longer culturing times, it goes right to the fridge for 8 hours. This allows the yogurt to solidify and stops the bacterial action. 

8. Save some yogurt to make your new batch (optional)! You can keep making yogurt from your own, although allegedly, at some point it you’ll need to start over with yogurt made directly from straight up bacterial cultures (i.e. store bought – or you can buy your own cultures online). I have yet to keep it going long enough to experience this (usually I forget this step before it’s been all eaten up – 5 times is the most I’ve “reused” my own yogurt and so far so good). 
Yogurt starter!

For a thicker yogurt: You can add either tapioca starch (not the beads, which I’ve done – you get tapioca yogurt…very strange…) or nonfat dry milk. I’ve found that adding the thickeners before you heat the yogurt allows them to dissolve more completely and you end up with a smoother texture (especially the tapioca – if you don’t, it’ll all settle to the bottom). I prefer the dry milk to the tapioca – I think it enhances the flavor rather than just making it thicker. You can add the dry milk when you take the milk off the heat with pretty similar results. You cannot do this with the tapioca powder without getting clumps.

Attempt #1 at Greek-style yogurt - a sieve works much better
For Greek-style yogurt: After the yogurt has been in the fridge for 8 hours, you can plop your yogurt into a double-coffee filter or quadruple-cheesecloth-lined sieve and suspend it over a bowl. The whey will drain out overnight (8-12 hrs) and you’ll be left with a nice, thick Greek-style yogurt. You’ll lose about half the volume.

For something frozen: Not exactly like frozen yogurt you’d get in the store, but this stuff works great to make frozen fruit and yogurt popsicles. My kids love it blended with any kind of fruit and frozen into a mold or even into a little ¼ cup blob.

For flavored yogurt: 
Fruity yogurt. You can add fruit before you heat your milk (so it cooks a little in the milk and the flavors permeate. However, the yogurt will not set up very well and your yogurt will be runny, even with thickeners. If you like your yogurt thicker, a good bet is to just add fresh fruit or jam/preserves afterward.
Vanilla yogurt (a very slight variation of the food network recipe that started it all). Add one tablespoon of good quality vanilla extract to the cold milk before you start heating it. This allows the alcohol flavor to evaporate. Then once you take the milk off the heat, whisk in  ¼ cup of maple syrup.
Nora's Royal Strawberry Banana. Puree one banana and 5-8 strawberries (fresh work best, but you can use frozen if you need) with ¼ cup of maple syrup or honey. Add to one quart of plain yogurt. Increase or decrease fruit to get your desired amount of fruitiness. If you like chunks of fruit in the yogurt, you can smash the fruit with your fork.
Chocolaty yogurt. When made with a tangy yogurt, this one is reminiscent of chocolate cheesecake. In a separate bowl mix 1 ½ tbsp unsweetened cocoa powder, 1 ½ tbsp maple syrup and ½ tsp vanilla extract until smooth. Pour into 1 cup of plain yogurt. Mix well. You can play with the ratios of cocoa to maple syrup to get what you like.
Yogurt from different starters, incubated for 7 or 14 hrs. Back 2 are flavored starters, Front 2 are plain.

Some things I’ve learned:
  1. Your yogurt starter will dramatically affect your end results. I’ve found out a few things along the way that will really help your end product turn out better:
    1. Make sure you check the expiration date of your yogurt starter. Use a starter that is as far from the expiration date as possible. The closer to the expiration date, the fewer bacteria will still be living in the yogurt, so you’ll have a harder time getting a quality yogurt product.
    2. Every place I found said you needed to use plain yogurt, although I’m not sure why. Personally, I have not had a problem with making yogurt from flavored ones. Some yogurts we wanted to use (like Activia or Gooberry Pie kefir) only come in flavors. The only thing I noticed was that the textures from flavored yogurts were perhaps a smidgen thinner.
    3. If you use a tangier yogurt, or one with a high, robust colony count (like kefir), you need a lot less time to get the same tanginess. You may have to taste test more frequently the first time you make it to get it the way you like it. 
    4. Pick a good quality yogurt with the types of cultures and amount of tang you want to imitate. You can splurge a bit. You will be growing the same bacteria in your yogurt as your starter, so choose something you like.
  2. The amount of milkfat in your milk will affect your end results. I’ve made my yogurt from skim milk, a whole milk and cream mixture, and every combination in between. The more fat, the thicker and creamier the yogurt. If you want a lower fat yogurt, you’ll probably need to add a thickener if you want it to have a “real” yogurt texture. My favorite is all whole milk (I also like a combination of 1% and whole). It gets a pretty great texture, even without a thickener and has the best flavor. It makes wonderful Greek-style yogurt, too! Just a note: non-homogenized milk (like the fancy-shmansy organic cream-top milk) does not set up very well – I will not be using it again.
  3. Pay attention to culturing temperature. Here’s where a yogurt maker would come in handy, although my heating pad/bowl contraption works pretty great. Start out at a lower temp. I’ve found it’s more forgiving. The lowest setting on my heating pad sits around 100 degrees. With a regular yogurt starter (like plain Dannon), I get a nice textured and tangy yogurt in about 16 hours. If I use a more highly cultured yogurt (like kefir, which has a much higher bacteria colony count and more strains of yogurt), I’d max out at 14 hours, but I can get a really nicely tangy one at 8 hours. But the great thing is, even if I forget about it or overslept and let it culture a couple hours too long (say, oh, 24 hrs), I can still get an awesome yogurt. 
  4. You can thicken your yogurt, but don’t expect it to be the exact same texture as Yoplait. Homemade yogurt just has a different texture. If you want to know what it’ll be like, it’s closer to your higher end organic yogurts like Horizon Organics or Kalona Supernaturals. Try to thicken it too much and it’ll end up like pudding. Despite what the back of your yogurt container says, do NOT use pectin. I totally curdled my yogurt. Oops.
  5. You can make yogurt from any kind of milk. Yes, even breast milk (and no, I haven’t gone there…yet…). If you want some very thorough directions on making yogurt from any kind of milk (and anything and everything you would ever want to know about yogurt making), check out the free yogurt-making guide at
  6. Speaking of breast milk. There’s a reason your breastfed baby’s poo smells like yogurt. One of the bacterial strains that can be used to make yogurt (Bifidobacterium infanti) is the first bacteria present in the intestinal tract of infants. So basically your baby turns your milk into yogurt poo. Although I wouldn’t recommend eating it...

Well, that’s that. Let me know if you come up with any great recipes or find out anything interesting. And may your digestive tract thank you.


  1. If you are still making yogurt a quick cost saving hint. To make thicker style yogurt, we pour it into a colander lined with an old kitchen towel. I'll get the almond yogurt recipe from Brooke too for you.

  2. Hello, everyone how are you?

    hope you all are doing great. by the way, i just started my first yogurt blog and which is great.
    please read my blog and get benefited yogurt information
    yogurt thanks