Why Your Yogurt Isn’t Turning Out: Easy Fixes

Homemade Yogurt

Is your raw milk yogurt runny?  Does your homemade yogurt separate?  Is it foamy?  Too sour? Too liquid?  Not sour enough?  Each week through Nourished Kitchen’s facebook page, and by email, I receive several questions about troubleshooting homemade yogurt.  Here’s a list of the most common questions on making homemade yogurt, working with starter cultures and troubleshooting your yogurt when things go a little awry.

How do I make yogurt?

To make yogurt, you need milk and a starter culture.  The starter culture is typically freeze-dried yogurt that contains live active bacteria, and each yogurt may offer a different flavor or array of beneficial bacteria.   There is a wide variety of yogurts from which to choose, each with their own unique characteristics though they share the common benefit of producing a cultured dairy product that is rich in food enzymes, increased B vitamins and beneficial bacteria.  After culturing with a powdered starter, you can use the yogurt you have prepared as a starter for future batches of homemade yogurt (this does not apply to raw milk yogurt, see below).  You also need milk which can be any mammalian milk, cow’s and goat’s milk being the most commonly used varieties.  For questions on non-dairy yogurt, continue ready below.

What are “thermophilic” and “mesophilic” yogurts?

Thermophilic means “heat loving” and it refers to yogurts that culture best at a slightly elevated temperature of 108 – 112 F.  This includes the yogurts you typically purchase at the store, and Greek and Bulgarian yogurts.  Mesophilic, by contrast, refers to yogurts that culture best at room temperature or at 68 – 78 F.  Mesophilic yogurts include viili, matsoni, piima and other styles.

How do I know my yogurt is done?

You know your yogurt is done when, after culturing it for the recommended period of time (8 to 12 hours for thermophilic yogurt, and 24 to 48 hours for room temperature yogurt), it pulls away from the sides of the jar when you tilt it.  This indicates that the proteins have coagulated and your yogurt has finished culturing.

Why is my raw milk yogurt runny?

Raw milk yogurt is runny for two reasons: 1) raw milk is rich in food enzymes and these food enzymes will continue to digest the milk and produce runny or liquid yogurt and 2) raw milk’s proteins have not been denatured through heat.  Scalding or pasteurizing milk denatures its proteins to some extent, and this allows them to be reorganized and better coagulated during the culturing process.  A runny or liquid texture is the natural state of raw milk yogurt.

Why did my homemade yogurt separate or turn lumpy?

Culturing yogurt for too long, at too high a temperature, or with an unreliable  or compromised starter culture can cause yogurt to separate or turn lumpy.  If your yogurt turns lumpy, strain it to remove the whey, then beat the yogurt solids in a bowl with a whisk until it turns smooth.  Also, make sure to culture thermophilic yogurts at temperatures of 108 to 112 F and room temperature yogurts at 68 to 78 F.  Also, make sure to use either a purchased powdered starter, or a fresh starter no older than 1 week.  After 1 week, the cultures in yogurt may deteriorate and may not be as effective at culturing milk to produce the style of yogurt you prefer.

Why is my yogurt too sour (or not sour enough)?

The hotter the temperature at which yogurt cultures, the sourer it will be.  Similarly, the longer it cultures, the sourer it will be.  In our home, I love a slow-cultured yogurt that has been cultured for 24 hours which is longer than most thermophilic yogurts; however, the typical culturing time is 8 to 12 hours.  If your yogurt is too sour, culture it at the lower range of temperatures listed for your starter, and for a shorter duration until it acquires the flavor you like.

If you like a sourer yogurt, simply culture longer until it acquires the flavor you like.  Note that, with extended culturing, it may separate or turn lumpy (see above).

Why is my yogurt foamy/stringy and why does it smell like beer/bread?

If your yogurt is foamy, stringy or smells yeasty like beer or bread, it is likely contaminated by yeast.  This can be yeast from baking, or wild yeast naturally present in your home and on your hands.  To prevent it from happening, make sure to practice good hygiene in the kitchen, using clean equipment.  Also, avoid baking yeast-based breads (including sourdoughs) on the day you make yogurt to avoid cross-contamination.

Why is my homemade yogurt grainy or gritty?

If your yogurt tastes fine, but has a weird gritty or grainy texture, this typically indicates that you heated the milk too fast. Allow the milk to come to 180 F more slowly next time.  When I make yogurt, typically 1 gallon at a time, it will take 45 minutes or longer to come to the right temperature.

Why is my homemade yogurt moldy?

Very rarely, someone experiences mold on the surface of their yogurt when making room temperature yogurts.  This can be due to a few issues: 1) poorly cleaned jars and utensils, 2) very old milk that wasn’t properly heated and then cooled down prior to culturing, 3) a compromised starter culture.  Discard the yogurt, and start fresh with a new starter and clean materials.

Can I use any milk when I make homemade yogurt?

When making traditional and room temperature yogurts, you can use any mammalian milk.  You do not need to make adjustments to the recipe, they will all perform, more or less, the same way.  Common milks include cow’s milk and goat’s milk.

If you wish to make yogurt from non-dairy milks, you will need to seek out and use a starter culture designed for non-dairy milks (like this one). Non-dairy milks will culture, but typically do not thicken like dairy-based yogurts.  To create a thick non-dairy yogurt, you will need to add gelatin, agar agar or another thickener.

Why do I have to heat pasteurized milk to make yogurt?

It may seem silly to scald pasteurized milk prior to making yogurt, but it’s effective in ensuring that you make the best quality yogurt you can.  Pasteurized milk can often become contaminated with stray microbes during packing, after pasteurization is complete.  Bringing the milk to 180 F and then cooling it down to the appropriate temperature for culturing will kill any stray microbes, ensuring the milk will not be contaminated as it cultures.

How do I make my yogurt thicker?

You can make your yogurt thicker by using whole milk, or adding cream to your whole milk yogurt.  Some home yogurt makers add milk powder, but due to its refined nature and the presence of oxidized cholesterol, this is not a solution I use in my kitchen.  You can also thicken yogurt by straining it.  To strain your yogurt, place a fine-mesh sieve (like this one) over a large mixing bowl, and line the sieve with a double layer of cheesecloth or a single layer of butter muslin (available here).  Pour the yogurt into the muslin-lined sieve, and let it sit until thickened to your liking, about 6 to 18 hours depending on how you like it.

Where to learn more about yogurt making.

Still have questions about yogurt? Want to perfect your yogurt and other homemade foods?  Check out the resources listed below:

  • Get Cultured! An online cooking class with 50+ videos devoted to *ALL* things fermented and cultured.  There’s three sections on culturing dairy, including yogurts, kefir, clabber, butter and more.  Check it out here.
  • The Art of Fermentation.  A comprehensive book on fermentation in history and the fermentation movement as a whole, with a great deal of information on yogurts and other cultured dairy products. Check it out here.

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What people are saying

  1. Trinity says

    Hi Jenny :)
    If my yoghurt has gone too sour can I still use it as a starter for my next batch or do I need to get a new starter?

    • Joe says

      You can reuse your too-sour yogurt, it has the right bacteria. Next time, reduce either temp. or time. Take notes! Also, something not mentioned in the article, but use of higher fat milk provides less sour yogurt (if you are using skim, simply experiment with 1% or 2%…I always use whole milk, and I find I enjoy it without needing to add honey, jelly, or anything else).

    • says

      If you have a runny yogurt it will probably only make runny yogurt. If the only problem is that it is sour then use it. The longer the yogurt ferments the more sour it will be. My yogurt generally gets really firm within 6-8 hours. Longer than it starts to sour. Mine never goes sour unless it stays in heat too long.

    • Karol says

      Yes, but it would be unnecessary. If you cool the milk well and add an adequate amount of living bacteria, you should not really need to add gelatin for a nice thick yogurt.

  2. says

    Good tips–for me the culprit is letting the yogurt get too hot while culturing. It doesn’t ruin it, but it’s not pleasant to eat either. I use it place of buttermilk in baking or in smoothies. I also agree that straining it is the best way to thicken it–yummy!

  3. Lisa Marxuach says

    I just milked a cow that gave birth 2 days prior. She has WAY (whey??) ;) more milk than her little calf can consume so while the babe suckled off one teat, I milked the other 3 and made yogurt with some of it. It’s a rich yellow color – still full of colostrum! This yogurt is incredibly delicious & I will use it as the culture for my next batch after her colostrum is long gone which in my way of thinking, will continue to produce an even more beneficial yogurt!

  4. MR emmanuel says

    HELLO PLEASE HOW CAN I MAKE YOGURT , WHEN DID I NEED TO ADD STATER , AND HOW CAN I ADD GELATIN TO MY YOGURT, WHEN DID I NEED TO ADD WATER TO MY YOGURT.
    THANK YOU.

    • Karol says

      Heat milk to nearly boiling in a pot with a long spoon in it and the lid partially on, stirring occasionally.

      Cool the pot with lid and spoon in a large mixing bowl of ice, stirring occasionally.

      Make sure the side of the pot is not warm to the touch at all.

      Mix in about 1 cup of yogurt from the store per gallon of milk with the spoon you have been using.

      Take out the spoon and cover with the lid that had been on it during heating.

      Leave it in a warm place (not warmer than 115 F) for 7 to 24 hours.

  5. mscarried says

    hi, I was using a store bought bulgarian yogurt as a starter and it made lumpy (but yummy) yogurt. Rather than go get More yogurt, Can I use this lumpy yogurt as a starter for a new batch? also can I use just the whey as a starter? thanks for your tips!

    • Karol says

      You can use your yogurt as a starter, but only if you have a cup or so of it that has not been contaminated with other bacteria (i.e. leaving it open while you serve the yogurt, using a spoon that has not been boiled to serve, etc.) I use my yogurt for new batches by scooping out a cup with a sterilized spoon into a baggie as soon as it is done fermenting. I keep this baggie in a cup in the fridge undisturbed until I am ready to use it. Then I cut the corner off and carefully squeeze the starter into the sterilized milk.

      Note: Do not use your yogurt if it didn’t turn out nice and thick… it probably won’t have enough bacteria alive in it to work. Incidentally, I leave my yogurt to ferment for 24 hours, which may also account for why I always have enough bacteria to use my own yogurt as a starter. If you don’t like the tang of this level of fermentation, you can just buy store yogurt to start your homemade yogurt.

  6. Sherri says

    My yogurt looked right, smelled right, but tasted bitter. (I threw it out)
    Did I keep it too hot? (It was still lukewarm after 12 hours) or what else could I have done wrong?

    • Karol says

      Most likely some foreign and unwanted bacteria were introduced during the fermentation process. Make sure that your process for sterilizing the milk and everything that touches it does not leave a gap where unwanted bacteria might be able to enter.

      Trust your taste buds on fermentation. When in doubt, throw it out!

  7. Karol says

    About thick homemade yogurt:

    I have been making yogurt for years, in a plain old metal pot with regular whole milk from Walmart. I have found that the trick for thick yogurt (like so thick it doesn’t lose its shape when scooped into your bowl) is to make sure your milk is cool before adding the starter (i.e. acidophilus capsules or yogurt from the store, etc.). If the milk is warm at all, the temperature difference will shock and kill some of the bacteria and you won’t have enough left to get the fermentation that will yield a nice thick yogurt. With this method there is no need to use any additives or evaporation of milk, and no magic temperature to heat the milk to for a certain length of time. I just put my frothy/steaming milk pot into a giant mixing bowl of ice for a few minutes, and stir with the same spoon I used while heating. Once it melts all the ice, I stir in the starter (with the same spoon), cover it with the lid (sanitized by the steam from the heating of the milk) and put it in a nice warm place. 24 hours will yield yogurt with a higher amount of probiotics that is thick and rich and delicious.

    • sarah says

      Hi I’m looking for advice on making yogurt. My family eat it a lot so I use 4 pints of milk and half a cup of yogurt but it keeps going wrong. How much yogurt would you advice to use with 4 pints of whole milk.

      • sarah says

        Could you also advice me on what bacteria capsules I could use (with how many cultures) when making my own starter. I tried to get acidophilus in the herbal store but there are so many different amounts of culture in each one, I didn’t know what would be too much

  8. Catherine says

    Here is my dilemma: I have been buying yogurt from my local farmer’s market. It is made by a young woman who works there (“Jersey Girl”) and she uses the raw whole milk that they sell. She makes it in half pint mason jars and puts fruit on the bottom of each jar. It is delicious! It is called French cultured yogurt and, because she uses whole, non homogenized milk, it gets a little layer of cream at the top. She does not add already made yogurt to the fruit on the bottom jars but obviously cultures it right in the jar.

    When I make plain yogurt (with the same milk) or put a little flavored honey on the bottom of the jar, it turns out just as good as Jersey Girl’s. However, when I put a little fruit on the bottom, it gets a little bit of water (about 2 tsp) at the top between the layer of cream and the yogurt. Even when I let it culture a bit longer (12 hours a opposed to 8), it STILL has that water at the top.

    Jersey Girl would not give away her secret to making that fabulous yogurt so I thought I would ask you!

    Thanks!

    Catherine

    • Karol says

      One idea is to ferment the yogurt for less time. The “water” on the top is separated whey. When the whey separates, this causes the yogurt to be thicker. Just like in cheese making, more acid means a better separation between the yogurt and whey, and this greater acidity may be coming from a fermentation time that is too long. Additionally, the berries probably add a little more acid too.

      I have never cultured the berries in there with the yogurt, but if I did, I might consider boiling them for a minute so as to not introduce any unwanted bacteria/yeast.

  9. Donna says

    I just made homemade yogurt for the first time. I used almond milk and non-dairy culture, and kept it in the yogurt maker for 15 hours. It came out fine, but a layer of water surrounds the clump of yogurt on the top and bottom of each jar. Any thoughts about why that happened? Thanks!

    • Karol says

      Just pour this liquid off, it is the whey (see my last post above). It also makes a healthy drink, according to Nourishing Traditions. Or, it can be used for soaking grains.

  10. Donna says

    Can I use my own home-made yogurt from my batch to make the new batch and then use it from that batch to make the new, over and over or should I buy yogurt from the store every so often?

    • Jenny says

      As long as you’re making homemade yogurt from pasteurized or scalded milk, you can use your existing yogurt to culture new batches. If you’re using raw milk, your yogurt starter will degrade over time as the bacteria in the raw milk compete with the bacteria in your starter.

  11. Karl says

    Hi,

    I have a batch of viili that had been in my refrigerator for year in a sealed glass jar. Is it still possible to revive the batch or is it a lost cause?

    Thank you!

  12. Judy says

    I attempted to make coconut milk yogurt yesterday in my excalibur dehydrator. I make the coconut milk from boiling 2 c filtered water and then pouring it over 1.5 c og coconut flakes and blend in the vitamix. Then I let it cool to about 105-110°f, added my starter (which if a GI Prohealth starter), blended will and put in my mason jars then in dehydrator. I know nut milk take less time than dairy, so I ran it for 12 hours on the 110°f setting. My coconut water and cream separated, and only saw some cultures form on the bottom of the jars. I cooled it anyway and out in fridge. Tasted it next morning and it was slightly sour, but watery. I used it in a smoothy…hoping there were some probiotics in it, lol. What did I do wrong? Any suggestions?

    • Jenny says

      I think the problem is that you used coconut milk to make yogurt. Coconut milk is a non-dairy milk, so it is not well-suited to yogurt making. Instead, you make cultured coconut milk which is faintly sour, liquid and prone to separation. You need to use dairy, OR, you need to add thickening agents to your coconut milk like gelatin or agar agar.

  13. Scott says

    I’m also using the Get Culture starter. The first two batches came out fantastic, but the last two have a slight cheese flavor/smell. The texture is acceptable. Any idea of what went weird with the last two batches? I’m guessing I can try to incubate it longer.

  14. Kay says

    I made coconut milk yogurt using canned coconut milk, gelatin and 60,000 probiotic capsule. I used my yogurt maker which uses a large container to incubate rather than small ones. It got nice and thick after refrigeration but it smells awful, doesn’t taste bad just sour. Used the process recommended by Danielle walker in against the grain cookbook. I’m thinking it must be bad, but can’t figure out what went wrong.

    • Jenny says

      I think the problem is that you used coconut milk. Coconut milk is not milk, and you can’t expect it to perform the same as real milk when you culture it or prepare dishes from it.

  15. says

    I know that leaving yogurt to culture longer will result in tarter yogurt, but is there anything I can do to a batch I’ve already made that is just super mild? It’s nice and thick (it was even before I strained it), but it doesn’t even taste like yogurt. I can’t find starter here in Costa Rica, so I just used whole milk yogurt from the grocery store as starter. I also use UP milk from a carton because it’s the only whole milk I can get except when I go to the farmer’s market and find the milk vendors. I would normally save some of this batch as a starter for the next batch, but I don’t want another week’s worth of blah. Thanks!

  16. Jasmine says

    Jenny,

    Im making my yogurt using Easiyo ( yogurt maker).
    I didnt follow the instruction completely but it turned out to be okay after put on set in a provided easiyo container approx 25 hours. it is thick and smell good but no taste of sour.

    It has been instructed to put in set for not more than 24 hours.

    Can we set the yogurt for more than 24 hours? Would it inviting the bad bacteria?
    Or the good bacteria would be decreasing due to long set hours?

    Your view. Thank you.

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