|You see, lactose or milk sugar is a disaccharide, okay, composed of two simple sugars: one molecule of glucose and one molecule of galactose. Now you can't digest this stuff without dissolving the bond that holds these two things together. And that requires an enzyme called lactase.||
| Now when we're babies, we all make plenty of lactase. Wh ...
AB: Where'd you get that?
Cute little fellow.
Baby Alton Brown
When we're babies we make plenty of this stuff because we've got to digest our mother's milk. But when solid food comes into the picture later on, 20 percent of European descendents, 80 percent of African descendents and almost a 100 percent of Asian descendents just stop making lactase. So when any of us drink dairy or eat dairy we consume a lot of these molecules which move unhindered through our systems. That is, of course, until they get to the colon. And there, armies of hungry bacteria latch on to the lactose and consume it. And in doing so they produce a lot of gas—hydrogen, methane, things like that—and that feels a lot like this.
LM: [punches AB in the gut]
AB: [doubles over]
LM: I'm not a doctor but that HAS to hurt.
LM: What's that you say? You can never have milk products again, eh?
LM: You say that yogurt contains bacterial cultures that love nothing more than snacking on lactose?
LACTOBACILLUS BULGARICUS & STREPTOCOCCUS THERMOPHILUS: [come and drag LM back inside]
LM: Wait. Wait. Guys. Guys. I'll give you 5 dollars if you beat him ...
[we hear a beating in the background]
Those cultures, by the way, produce lactic acid which is responsible for yogurt's creamy texture and, mmm, wonderfully tangy flavor. They also happen to be really good for you ...
LM: Ahhh! [glass breaks]
... unless of course you're Lactose Man. So stick around, won't you? Because when you strip away its commune-livin', VW-bus-drivin', earth-shoe-wearin', hippy image, yogurt isn't just good for you, it's good eats.
The best thing about making your own yogurt is that you get to pick the milk that goes into the yogurt. Any
milk will do. You could use goat milk, yak milk. It doesn't matter. But if you're a suburbanite like myself odds are good that you're going to
stick with good old cow juice. I like organic brands because organic dairy cattle are generally fed a better class of feed than their mainstream
sisters and I can taste the difference.
Which one do you use? Well, you could use whole milk but I think the fat kind of gets in the way of the protein coagulation. Makes for a loose yogurt. Skim goes the other way. There's no fat and so you get kind of a grainy texture. I think that 2 percent milk which has had 98% of its fat removed* is the perfect balance between flavor and texture, okay? So you're going to need a quart of that. You're also going to need half a cup of plain yogurt, okay? What is important is that it says on the label "contains active yogurt cultures" or it "contains live cultures". That is the only way to be sure that the bacteria inside are still alive. If it just says, "made with live cultures," well, that's basically a code phrase for, "they used to be alive but then we heat treated the carton and now they're dead."
Oh, and I always get my milk in opaque containers. Why? Vitamins are light sensitive.
Straight from the cow, milk is teeming with microorganisms. They really dig the high nutrition and cozy pH. [holds a magnifying glass up to the milk where we see little microorganisms floating around and dying] Too bad for them that the USDA requires that all commercial milk be pasteurized, that is heated to the point that everything in there goes belly up.
1 Quart 2% Milk
This environment is ripe for re-colonization. But first I like to add some extra protein in the form of powdered milk, half of a cup per quart of milk. More on why later. I also add a couple tablespoons of honey to kind of round off the tanginess of the yogurt. There. Now, whisk to combine and then reheat this to 120 degrees over medium heat. There we go.
1/2 Cup Powdered Milk
2 Tbs. Honey
Heat To 120°
Now how are you going to know when it is 120 degrees? Well, a probe thermometer is the best
tool for the job. But, gosh. If we just drop it in there, it's going to sit on the bottom of the pan and read the pan instead of the milk and
that's not good. So, use a metal paperclip—one of these little guys—right on the side of the pan. Just run the probe through and then open up
one side and it will hold the probe. Perfect.
Set this for 120 degrees. It'll only take a few minutes. Oh, and meanwhile go ahead and get half a cup of yogurt coming up to room temperature. You want those bacteria hungry and kicking when we get ready to put them in.
Now we want to cool this down to about 115 degrees and by pouring it from here into our incubation vessel, we should be able to do that. Now you can use any tall vessel that you want as long as it is very, very, very, clean, okay? If there's any bacteria in there at all, it might overwhelm our guys and then our yogurt would end up, well, rotten milk, okay?
Now we want to thin out this yogurt just a little bit. So I'm going to just barely whisk in about a cup into the yogurt. It's going to make it a lot easier to integrate. There. Now everybody into the pool. There. Now as soon as they are whisked in, those bacteria—now that they are nice, wide and awake—are going to get to work munching away. By the way, speaking of bacteria ...
Whisk 1 Cup hot milk into 1/2 Cup room temp. yogurt
Add yogurt mixture back to warm milk
... I never properly introduced the microscopic tag-team that's responsible for putting the "yo" in yogurt: lactobacillus bulgaricus and streptococcus thermophilus. Now upon entering the warm milk, the streptococcus goes to work right away, consuming lactose and producing, well, a lot of things, including lactic acid.
[ST places feet in "yogurt pool" which begins to bubble]
Once an acidic environment is established, however, he's not real comfortable hanging around. So he tags off with lactobacillus who prefers working in a tangier environment.
[ST removes his feet and LB puts his in]
Of course, he creates an even more acid until the milk becomes acidic enough that the proteins denature and then coagulate. This results in the soft, custard-y gel we all know and love. The more protein that's present, the firmer the gel which is why I added powdered milk to the mix.
AB: Thanks fellows.
This bacterial metamorphosis is called fermentation and it is the process by which we get a lot of really wonderful things: wine, beer, vinegar, sourdough bread, dill pickles and a lot of the world's great cheeses. Now successful fermentation requires control, okay? You've got to control which bacteria are present in the food, got to control the temperature at which they eat, and we've got to control the length of their work day, so to speak.
|Now since we're starting with pasteurized milk and we're keeping everything very clean, we've taken care of number one. As for number two, well, these bugs like to work between 100 and 120 degrees with 115 being ideal. Below that they go to sleep and above that they go to sleep forever. Maintaining this type of temperature will require some specialized hardware ...||
115° is ideal for
HAND: [tries to hand him a yogurt maker]
Sure, a yogurt maker would do a great job.
AB: What else does it do?
Take up space. That's what I thought. Nah, there's got to be a multi-tasker around here somewhere.
[AB goes to closet and pulls out a bucket and heating pad]
Ah, perfect. Ha, ha, ha, ha.
When exposed to bright light, a gallon of milk can
lose 80% of its riboflavin (vitamin B2) in two hours.
[AB has placed the heating pad inside the bucket which is wrapped around the container of yogurt]
|Perfect. Of course, finding the right heat setting for the heat pad is going to require some experimentation and you may want to test this with water first. But hey, once you know you know, you know? Now I'm going to guess medium is going to do the trick here. But just in case, I'm also going to use a thermometer. I'm going to set it to go off at 118 degrees. That way I'll have warning in case my inoculation team is headed for certain death at 120.||
Set yogurt into a container lined with a heating pad.
Set heating pad to medium
|The final issue, of course, is time. How long 'til it's yogurt? Well, it kind of depends on what you like. In as little as three hours you can produce a kind of tangy cream, kind of like crème fraîche. Add 9 hours to that and you'll have a solid block of tingly tang. I like to go in the middle, 6 hours. I think that that really produces the best balance of both flavor and texture.||
Set Timer For 6 Hours
What was once a liquid is now a solid, or a gel, to be more exact. Prompt refrigeration will send the bacteria into suspended animation, thus shutting down the fermentation process, which is important. Leave that in there overnight and come morning, your patience will be rewarded.
Mmm. Mmm. Personally, I like my yogurt plain. But there's nothing wrong with making an addition or two as long as you remember homemade yogurt does not contain gelatin or other stabilizers. So the more you stir it, the more the gel matrix is going to break down. So if you want to add granola or fruit, think fold not stir. Of course if you like your yogurt kind of runny and loose, well, stir away.
|Oh, this also means that anytime you cut into this big curd, you're going to have some whey puddle up inside, okay? Do not try to stir that back in. Just drain it off or blot it with a paper towel. Or you can leave it—it's loaded full of protein—if you want.||
|Oh, you say this looks like too much yogurt? You're just not thinking about all of the culinary options. For instance, yogurt can replace half or all the mayonnaise in traditional salad dressings. Don't believe me? Okay. Whip up a little something we call Million Island Dressing. Whisk together a cup of plain yogurt with two tablespoons each vegetable oil and tomato sauce. And then add two teaspoons each lemon juice, dry mustard, and sugar. Then about a teaspoon of kosher salt and half a teaspoon of black pepper. Okay? Then fold in half a cup of diced onion along with a tablespoon each of pickle relish and chopped green olives. And finally, one jalapeño chile minced very fine. Now that is good eats.||
1 Cup Plain Yogurt
Yogurt is to the Balkans what rice is to Asia:
a staple served at almost every meal.
Ever notice how you can simmer a cream sauce all day long and never seem to have any ill effects? While on the other hand, take a yogurt sauce and just show it the heat and look at what you get. Mmm. Good eats, no? No. What's the problem here? Well, it's got a lot to do with the way that ... Shall we dance?
GUEST: Young Man & Young Lady
[AB puts on some slow music while the young couple slow dance]
When proteins get hot they tend to tangle up tighter than teenagers at a dance. And when they bond up tight enough, they over coagulate. And when they over coagulate, they can curdle. And any cook or parent will tell you that leads to trouble. Now cream sauces don't curdle and here's why.
AB: Excuse me. Thanks. Thanks. [cuts in on dance, YM tries to get back YL]
The don't curdle because cream contains fat, okay? And these fat molecules get in between the proteins and prevent them from bonding. No bonding, no over coagulating, no troubles. Of course, with yogurt sauces it's different. You see, yogurt's made from low-fat milk so there aren't a lot of fat molecules to go around so those sauces curdle. This means that if I want to use yogurt instead of cream in my favorite tarragon cream sauce, I'm going to have to elicit the help of some kind of molecular chaperone. I'm going to have to find something ...
AB: [to YM] Oh, just take her.
... I'm going to have to find something that can get in between those, those molecules. I'm going to need something big. I'm thinking starch.
|Take your saucier or a large skillet and put it over medium heat. To that add the oil, the salt, the onion, and the garlic. Now since this is a sweat and not a sauté we can start all of this in a cold pan. It'll be all right. Remember we're not looking for color on this, okay? We just want to get it translucent. So stir often and keep your eyes on it.||
2 Tbs. Olive Oil
|Now in the mean time we're going to construct a slurry. Now a slurry is basically any cold liquid that has starch particles suspended in it. Usually it's used in sauce making to thicken things like gravies. If you've ever made a Thanksgiving gravy, no doubt it was thickened with a slurry. In this case we're actually combining the corn starch with the chicken broth so that it will evenly and quickly integrate into the yogurt, okay? It's first going to cook—the starch granules are going to swell up very, very big—and then it is going to be a chaperone just like over there. The key is even distribution of particles so you've got to shake vigorously.||
2 Tbs. Cornstarch
Shake To Combine
Yogurt may be the oldest processed milk product,
predating cheese by several millennia.
|That is a sweat. Time to add the slurry. I like to give it a couple more shakes right before it goes in. By the way, shaking is always better than whisking because it lets air get into the equation better. So I'm going to turn up the heat and pour in the slurry. I'm also going to go ahead and add the tarragon. Ordinarily, herbs go in towards the end. But since we're using dried, it'll live.||
Sweated Onions & Garlic
1 1/2 Tbs. Dried Tarragon
|Since corn starch gelatinizes or expands in liquids well below the boiling point, the mixture is going to thicken a lot faster than a flour slurry would have. This looks about right. So I'm going to turn off the heat and add the yogurt. Hey, wait a second. That mixture is so hot it would curdle this yogurt before the starch had time to get in there to prevent it. So, we're going to temper this they way we would an egg custard. Excuse me.||
1 Cup Yogurt
We'll need a big bowl. Yogurt goes in the big bowl and we're going to add a little bit of the slurry mixture at a time, just whisking it in a little bit at a time. It's going to slowly bring up the temperature of the yogurt so that it won't curdle. A couple more dollops and there will be enough starch in there to keep anything bad from happening. There. Now all of this goes back into the pan. And whisk to combine.
Now at this point since the yogurt was cold, this has probably dropped way, way too much in temperature to serve. But don't be too sure. I'm going to give it a taste before we put the heat to it. Mmm. That's good but it is a little bit on the cool side. So turn the heat to low, the very lowest setting, and whisk constantly just until it is hot enough to serve. What to serve it on? Just about anything. I like this on fish. I like it on chicken. I like it on almost any vegetable, eggs, oh, and my favorite, braised carrots.
Turn heat to low to warm the sauce.
As miraculous as milk's transformation from mellow liquid to tangy gel to salad dressing to savory sauce may
seem, there's yet another metamorphosis to come, yogurt cheese, which is "whey" better than it sounds. 'Whey' ... never mind.
Fundamentally speaking, there's really only one big difference between yogurt and cheese, the whey. The cheese has had the whey removed before the fermentation process. Of course in yogurt it's still there. Remember, whey is that liquid—very protein laden liquid—that won't coagulate no matter what you do to it. So it makes sense that if we could find a way to get the whey out of our yogurt, we'd have cheese, very basic cheese, but cheese nonetheless.
|To do this, we've got to get some pressure on to the yogurt. That's the same way that the cheese people do it. So here's what we'll do. We've got a nice big container. We've got a strainer that will fit down on top of that. Oh, we'll need some cheese cloth. I'm going to say about 2 layers of cheese cloth. There. Okay. Into the sink and, oh, we need a spatula. Perfect. Now before we dump in the yogurt I'm going to break up the curd a little bit and that will help to release some of the whey and get it flowing. There.||
2 Layers Cheesecloth
|Now this is actually two batches of homemade yogurt, okay? Two quarts. I figure I'm going to lose about half of that during this process. So that's going to leave me with a quart of cheese. There. Perfect fit. Now just fold the cheesecloth over and that'll keep it clean.||
2 Quarts Homemade Yogurt
|Now we could just park this in the refrigerator and let it drain naturally, it's already gone to work. But that could take a better part of two days and I don't know about you, I'm not that patient. So, we'll provide a little weight. There. Just a lid from another container and a can of, well, creamed corn but hey, you can use whatever you want. All right, this goes into the refrigerator and we let weight do the work.||
Refrigerate While Draining
Now you can see that we've got something that looks a lot more like cream cheese than yogurt. And feel free to use it thusly. It makes a wonderful spread. Mmm. Delicious.
Of course if you wanted something a little more exotic, say for your next cocktail party, you could start with one quart of your yogurt, okay, and stir in a teaspoon and a half of ground cumin, a couple tablespoons of fresh herbs—I like parsley—a teaspoon of kosher salt and about half a teaspoon of black pepper. Then let the cheese drain. The next day you'd end up with something that looks like this. You can tell your guests it's Boursin cheese, only good for them.
|1 Quart Yogurt
1 1/2 tsp. Ground Cumin
2 Tbs. Chopped Parsley
1 tsp. Kosher Salt
1/2 tsp. Black Pepper
After winning the 1908 Nobel Prize for medicine, Elie Metchnikoff spent the rest of his career investigating the connection between yogurt and longevity.
GUEST: Nicole Kerr, Registered Dietitian
So what we know for sure about yogurt and nutrition? Well, let's ask my nutritionist.
AB: Hi, Nicole.
NICOLE KERR: Hi, Alton.
AB: Have a cracker.
NK: Thank you.
AB: So what's the deal? What do we know?
NK: For those of you who are lactose intolerant, yogurt actually is a great source of calcium.
NK: The live cultures in yogurt have been shown to stimulate the immune system and to police the many flora that thrive in the lower G. I. tract. And then that means less ...
AB: "Tummy trouble." We just call it "tummy trouble."
NK: Right. But remember that cooking and freezing yogurt will wipe out the live cultures so you need to eat your yogurt straight up every now and then to receive the full benefits.
AB: Interesting you say freezing. Did you know it's actually easier to make frozen yogurt than ice cream?
NK: It is?
AB: Absolutely. Especially if you use yogurt cheese. You see, it's already coagulated so you don't have to cook it.
NK: I think there's another benefit for you to frozen yogurt.
AB: What's that?
NK: [whispers] Fat.
AB: [pauses, looks offended] No more of these for you.
|[voice over] Place four cups of your yogurt cheese in a deep bowl along with three quarters of a cup of sugar, a half cup of light corn syrup, two teaspoons of finely grated lemon zest, a tablespoon of minced, fresh, ginger and three tablespoons of fresh lemon juice. Whisk to combine and then pour into your ice cream maker and freeze per the manufacturer's instructions.||4 Cups Yogurt Cheese
3/4 Cup Sugar
1/2 Cup Light Corn Syrup
2 tsp. Lemon Zest
1 Tbs. Minced Fresh Ginger
3 Tbs. Fresh Lemon Juice
Whisk To Combine
Freeze according to manufacturer's instructions.
|When it starts to set in about 25 minutes, add a quarter of a cup of crystallized ginger, chopped fine. When the ice cream is done turning, move into an air tight container and harden in the freezer for two hours.||1/4 Cup Crystallized Ginger
Place in an airtight container and freeze for 2 hours.
Mmm, mmm. Ginger Lemon Fro-Yo. A dessert even a nutritionist could love. Too bad I had to run her out of here for that
fat-crack she made.
We hope we've inspired you to spoil some of your own milk in a controlled environment, of course. Even if you decide to stick with store bought, though, you should get your yogurt out every now and then and play with it. It's good fun, it's good for you and ... you know. See you next time. Mmm. Mmm.
Proofreading by Kristina and Sue Libretti
FACTS ALL COME WITH POINTS OF VIEW ... FACTS DON'T DO WHAT I WANT THEM TO.
I rarely sit down and watch Good Eats because it's tough to not get depressed over the loss of my hair and the expansion of my waist. I did however sit myself down to watch last night's airing of "Good Milk Gone Bad" simply because we had such a good time making it. (Never thought we'd get to use that "Leverman" suit again,) Imagine my despair when I caught a mistake! At the beginning of the yogurt making process I talked about the fact that whole milk usually contains between 3.5 to 4 percent fat. I then went on to say that 2% milk has had 98 percent of it’s fat removed. Wrong! If that were the case, 2% milk would have less fat in it than "skim", technically speaking. In reality, 2% milk has had about half of the original fat percentage removed. What I should have said is that 2% milk is 98 percent fat free. Is it a big mistake? No. But it is a goof all the same and I wanted to be the first to point it out.
Hope I don't get fired.
Last Edited on 08/27/2010