Greek Yogurt, Whey, and Protein

I fell in love with Greek Yogurt (from the local Iowa dairy Anderson Erickson) when it hit the market a couple of years ago (yes, we're a bit behind here in the midwest). Now I make my own. But I am confused about the protein and the whey.

According to all of the homemade Greek yogurt recipes I have found, all Greek yogurt is is regular yogurt that has been strained to make it thicker. When you strain it, you get a bowl of whey, which I then use in my bread baking.

When I buy Greek yogurt form the store, it has more protein than regular yogurt. But purchased whey powder is also sold as a protein supplement.

So, does the protein stay in the yogurt when you strain it, making it have more protein per ounce than before it was strained? Or does the protein go into the whey?

why whey? how much protein you consume on a daily??

yes.

like water and cup. they can be together, and it works fine. thats a reakky cool Idea Sdpicard to back your bread with whey. I actually like it.

you can't do any thing wrong. everything is fine.

I make Greek yogurt myself. My understanding is that, when you strain the whey from the yogurt, a small amount of protein goes with they whey while most stays with the yogurt solids (maybe about 75%). That smaller amount of protein in the whey is isolated in making whey protein powder. I think it takes a lot of whey to make a cannister of powder. The USDA has a Web site that breaks down the nutrient content of all kinds of food. You can search on "liquid whey" to find out what it's composed of. Choose the acid whey rather than sweet.

In making my own yogurt, I'm not able to match the protein content of the commercial Greek yogurts. For a cup I get about 16% protein, while the commercial yogurts are about 24%. My back-of-the-envelope calculation shows that the commercial producers that aren't using thickeners (like Fage and Chobani) must use about 3 cups of milk (or even a bit more) for every cup of yogurt. My ratio is about 2 cups for one cup of yogurt.

ETA: The USDA site is at: http://ndb.nal.usda.gov/ndb/search/list.

Thanks, jsd! That's helpful!

You're welcome.

I just realized I made an error in stating the percentage of protein in the whey versus the strained yogurt. (I just got done calculating the figures on a new batch of yogurt, so I noticed the error.) There's actually a lot less protein in the whey (8%--not 25%) than in the strained yogurt solids (92%--not 75%). The amount in my homemade yogurt is still the same--about 16g for a cup of yogurt.

Hello from a fellow Iowan!

It never occurred to me that homemade greek yogurt meant you'd sacrifice protein. I've used your identical recipe a couple of times.

When I need just a shade more protein, I will add a partial scoop of vanilla protein powder to my greek yogurt. Obviously you wouldn't do this when you're using the yogurt for a sour cream sub, but if it's a straight snack, it tastes great. Since you're in Iowa, I HIGHLY recommend the NNW protein in the black package at HyVee. It's made with stevia and is so good I can drink it just by mixing with ice and water. The Chocolate milk is the best!

How are you making your yogurt? I wonder if mine is the same as yours.

I take 1 gal. milk (1% is what I have been using lately), heat it to 180 degrees in a crock pot, then let it cool to 105-110 degrees.

I scoop out a cup of the milk and whisk in 6 oz. of Greek yogurt. Then I wrap it all up in towels and put it in the oven with the oven light on for 8-12 hours.

I don't know a lot about food and nutrition, but other than the addition of good bacteria, nutritionally there really isn't anything different about the yogurt than the milk I started with, is there? Or do the cultures alter the nutritional value of the milk somehow?

Your recipe and technique are almost identical to mine, except I start with 1/2 gallon of 1%. To that I add only 1 tablespoon of starter (from my previous batch of yogurt). I don't bother removing any of the milk. The small amount of starter seems to work fine. I also do the oven/light/towels thing for about the same amount of time. Last night was my shortest incubation period: 7-1/2 hours, and it came out fine.

As far as the nutrition, when you strain the whey, you're losing a small amount of protein, some carbs (yay!), a very small amount of fat (not enough to worry about), some calcium, and overall some calories. In other words, it's not all water. Here's my calculation for what is removed from the yogurt in 100g of whey (based on yogurt made with 2% milk--so only the fat figures would be different):

Whey from 2% milk, per 100g

Calories: 26.76
Total Fat: 0.09g
Sodium: 48mg
Total Carbs: 5.12g
Sugars: 5.12g
Protein: 0.76g
Calcium: 10.3%

For my last batch, from the 1/2 gallon of milk I started with (1935g), I strained out a little more than half the weight in whey (1015g).

Okay, I'm obviously obsessed with this topic. My goal is to make a Greek yogurt with the same protein content as Fage or Chobani. I think they have special equipment for straining it. They also seem to be able to get out more of the milk's sodium and carbs.

I know this thread is a few months old but I was just about to start a new one about homemade greek yoghurt and thought I'd tack it onto here

I'm desperately trying to replicate Fage's Total 0% Greek yoghurt. The ingredients list on a Fage Total 0% is pretty much milk & bacterial cultures. 100g yields 57kcal & 10g protein.
I make yoghurt using skimmed milk & skimmed milk powder (in an attempt to thicken & increase protein). 100g of strained yoghurt yields 100kcal & 10.6g protein. That's almost twice the calories.

When I look at the figures it seems the extra calories come from carbs (presumably the lactose sugars). I'm working out the calorie/protein content of the final yoghurt based on the figures for the milk/powder I'm starting out with. I'm slowly coming to the realisation though, that the yoghurt I'm making probably has less carbs in than the milk I'm starting out with. The bacteria ferment the lactose, producing lactic acid right? So the final yoghurt has less lactose (therefore less carbs) than the ingredients I'm starting out with.

I googled it after I'd figured this out and it looks like I'm right. This (less than scientific but straight forward) article probably explains it better than I have tried to >>> http://lowcarbdiets.about.com/od/whattoeat/a/yogurtcarbs.htm

So, after trying and trying to figure out how they get so much protein with so few calories, it looks like I may have been doing just that all along - I just didn't realise! If I have the same protein per 100g yoghurt then, chances are, the calories are probably about the same too. Happy days!

I just read the article in the link two posts up and It's a great read! So, when I enter my recipe for homemade yogurt, there is no way to account for the fact that the fermentation process is depleting the natural milk sugar. I guess that's good news--means that I am overestimating the carbs and sugar in my diet every time I log homemade yogurt!