My post about making Healthy Homemade Greek Yogurt is targeted by Google searches more than any other on this blog. It gets the most comments and questions, too.
Therefore, an update seems appropriate. Let me just point out that some of you have been making yogurt for many more years than I have, so feel free to chime in with your own experience, knowledge, or opinion.
The first three questions deal with troubleshooting: “Why did my yogurt fail?”.
1. Was your starter fresh enough?
This is crucial. In the beginning of my yogurt-making stage of life, the majority of my fails happened when I used a new starter–as in commercial yogurt from the grocery store. (By the way, you can use either regular unflavored yogurt or Greek yogurt.) I’m convinced it’s not always that fresh.
If your first batch or two gets slightly thick but it’s not what you wanted, I recommend making another batch with new milk using your “thin yogurt” as a starter. Unless there is some other problem, I predict it will be thicker the next time. If not, try different yogurt as a starter. Look for the fewest additives, live cultures and fresh, fresh, fresh.
I have not bought yogurt in over a year because I keep using a little bit from my previous batch. In my experience, you need to make it at least once a week for the freshest starter.
2. Did you keep your milk incubated at 100-110 degrees F? Consistently?
Another common reason yogurt fails is human error regarding incubation. It’s extremely important to keep the temperature constant. I have been known to actually forget to turn my oven on resulting in the milk sitting at room temperature for hours. When I discover my mistake, I usually turn the oven on and hope for the best. Whether it works or not depends on how long the milk sat there without being warmed.
If you are using a crock pot, a heating pad, an electric roaster or some other creative device (see comments on the original post to learn how some of my readers do this), check your temperatures with a thermometer until you are certain you’ve got it right. Test the environment, not the yogurt. See #3.
3. Was your milk disturbed in any way during the incubation process?
Yogurt bacteria are sensitive and don’t seem to like anything coming into their space when they are busy multiplying. Completely understandable, don’t you think? Avoid putting a thermometer or spoon in the milk. Do not stir. I give the bowl a gentle shake to check if it has set up. Once you pour it into a strainer, incubation is over.
If your yogurt has not set up after 8-10 hours, you could try adding more starter and putting it back in the oven. This works sometimes but not always. Worth a try.
4. Is it really necessary to heat the milk to 175-180 degrees since it has been pasteurized already?
If I could make yogurt without heating the milk before incubation, it would save time and I would be the first in line. So I decided to experiment. In response to a reader’s question, I tried two batches equal in every way except for the heating-then cooling process. I heated the milk like normal in one batch and then let it cool down. The other I simply brought to room temperature before adding starter. In the end, they both got thick but the milk heated to 180 degrees produced a thicker yogurt which is my ultimate goal. Looks like I will continue to heat just below boiling and then allow to cool back down below 120 degrees F.
5. I didn’t add dry milk solids or gelatin. Would it be thicker if I did?
Mine gets plenty thick without it. After forgetting to add dry milk a few times, I discovered I liked the texture better. It’s cleaner and smoother–not pasty. As for the gelatin, it’s not necessary. If you want it thicker, strain it.
6. Some people say I can’t make yogurt with non-fat milk. True?
No. I frequently use non-fat milk. I’m sure whole milk yogurt is absolutely delicious but just like drinking whole milk vs. nonfat milk, it’s what you get used to. And I prefer not to have to buy new clothes if you know what I mean. As has been noted already, I admit to a wicked yogurt habit.
7. The texture is not what I was expecting after I strained my yogurt.
This question has many answers depending on how you like your yogurt. I want mine to be super smooth with the texture of sour cream. This is accomplished by first straining to half the original volume. Much more than half and your yogurt will be more like ricotta cheese. Then I whisk it well to unravel the protein and add a little milk back to it until it’s the consistency I like. Creamy and dreamy. You could add whey back into it but what’s the point? Just don’t strain it as much.
If your texture is gritty, my research suggests several possibilities: Did you accidentally let the milk boil? Did your yogurt have any additives? See this post for more on the subject.
One other thing about texture. In the beginning, most of us have expectations based on what we buy at the grocery store. Many commercial products have additives we have become used to and are impossible to duplicate at home. And anyway, do we really want to? If you make your own very long, you will soon be addicted to fresh, unadulterated and customizable yogurt.
8. One last thing–what’s up with the skin on top of my milk as it cools.
My best answer to this “problem” at the moment is to loosely cover the heated milk as it cools. It prolongs the cooling process a bit but requires no extra hands-on time. Personally, I don’t cover it. I just wait until the yogurt is cooled and then remove the skin quickly with a flat spatula before adding the starter.
If you haven’t seen my video about making Greek yogurt, you can check it out here.
Still have questions? Leave a comment. I will try to answer ASAP.