31 Cold Start™ Yogurt FAQ

image from Fe Krubl

When I developed the Cold Start™ Yogurt method in June of 2017, I did not expect that it would become SO popular! One reason it is so popular is that it is very EASY to make. Another reason is that it TASTES so good!

I also did not anticipate all the questions that this method would bring, and putting all these questions/answers on my original Cold Start™yogurt post made it into a very long post.

If you are new to Cold Start™yogurt, please watch the video found here, then come back and see if you have any questions. This is the only place where you will find the original recipe, & complete information about Cold Start™yogurt. Enjoy!

Updated May, 2019
What is the Cold Start™ Method?
I came up with the name, Cold Start™ method, and it is simply using 2 ingredients: cold ultra pasteurized milk & a couple tablespoons of yogurt (also called starter), mixed together and letting the Instant Pot warm up your milk automatically to the perfect temperature. No heating or cooling your milk, and no additional or special equipment is necessary. "No Boil" is not accurate to describe this method, as milk is not boiled to make yogurt.

In the Traditional Boil Method, milk is heated to 160°-180°F using the "Boil" setting of the Instant Pot to make yogurt. Milk is then cooled to 100°F -110°F, starter is added, and incubated.  Incubate means keeping the milk warm, at a constant temperature of 100°F-110°F.

What if I don't have a Yogurt button?
You can still make yogurt; it will require a couple of extra steps to heat the milk and find a method to maintain the temperature of your milk in the 100°F-110°F range for at least 8-10 hours. An accurate thermometer is needed. You can find additional directions for No Yogurt Button here. 

What milks can I use with the Cold Start?
You can only use ULTRA PASTEURIZED milks or SHELF STABLE milks with this method. Shelf stable milks include: canned, boxed or powder milks. UHT (Ultra high temp) milks are the same as ultra pasteurized milks.

Why? Pasteurized milk is heated to 160°F, kills any harmful bacteria, but still has natural bacteria in the milk. This natural bacteria competes with the yogurt bacteria while the milk is warming up to incubation temperature. Results are thin yogurt that doesn't have very many yogurt cultures.
Ultra pasteurized milks are heated to 280°F, quickly cooled and are 99.9% bacteria free. While the milks are warming up to incubation temp, ONLY the yogurt bacteria is allowed to grow, resulting in yogurt! If you want to use any other milks to make yogurt, use the more traditional boil method.

When using Ultra Pasteurized milk, it will not be as thick as the filtered milks (Fairlife, CarbMaster, MooTopia or Natrel Lactose Free), but you can strain it to your desired consistency. Some ultra pasteurized milks need at least 10 hours incubation to set.

Fairlife Milk
Ultra pasteurized
Ultra filtered
13 g protein
6 g sugar
Lactose free
Available in Whole, 2%, 1%
rbST free

Darigold FIT is an ultra filtered, ultra pastuerized milk that is similar to Fairlife in composition.
14 g protein
7 g sugar (40% less sugar)
Lactose free (lactase enzyme added)
rbST free (No artificial growth hormone)

*Only available in 2% or Chocolate

Horizon Protein
Ultra pasteurized

12 g sugar
12 g protein

Kroger CarbMaster
Ultra filtered
Ultra pasteurized
11 g protein
3 g sugar
Lactose Free
Available in Nonfat only

HEB MooTopia
Ultra filtered
Ultra pasteurized
13 g protein
6 g sugar
Lactose Free
Available in 2%, Fat Free

Horizon Organic Milk
Ultra Pastuerized
8 g protein
12 g sugars
Available in Whole, 2%, 1%, Fat Free, High Protein (12g) & Lactose Free

*Most organic milks are ultra pasteurized. These are not ultra filtered milks, so you may get a thinner yogurt unless you try their Protein Milk.

Use the regular, not the iron fortified, for the best taste

Instant Powdered milk is a great option to not only make yogurt, but to add to other milks for a thicker yogurt. You can adjust the powder:water ratio for a thicker milk/yogurt or you can add 1/3-1/2 cup of instant powdered milk to every 8 cups of cold milk for a thicker yogurt.

Carnation Instant Milk Powder

Easily available and tastes great. Use it alone or in addition to milk to make a thicker yogurt. 1/3-1/2 cup of instant powdered milk added to 8 cups of cold milk will help make your yogurt thicker.

Not everyone has access to fresh milk, so dry, or powdered milks are perfect for the cold start method and you can make a concentrated milk by using half the amount of water that the recipe calls for. You can also add instant powdered milks to cold milk to help thicken your yogurt.

You may live in another country where fresh milk is not available. You may see Ultra Pasteurized, Ultra High Temp, High Temp Short Time (HTST)  or Extended Shelf Life (ESL) on the package.

Amanda Atchley, who lives in Japan, found this ESL milk. It took about 11 hours to set, which can be true of some ultra pasteurized milks. She also strained it for a thicker texture.

Here are some examples of boxed, shelf stable milks. Some people have found boxed milks at their local dollar store. 

I live in Canada. What milks can I use?
You can use any UHT (ultra high temp) milk with the Cold Start. Most organic or lactose free milks are UHT.
Fairlife milk is now available in some parts of CanadaJoyya is the closest in composition to Fairlife milk. Natrel lactose free milk, is another popular choice. 
Natrel filtered milks are NOT ultra pasteurized. Only the lactose free version is ultra pasteurized, so look for the orange label.

Do I need to use Sweetened Condensed milk?
No. You only need to use milk & a couple of tablespoons to make yogurt. Adding sweetened condensed milk is optional and is added along with the milk at the beginning. It adds sweetness, and thickens the yogurt.
You can choose ONE of the following, add it to your milk to flavor and sweeten your yogurt:

The higher the protein, the thicker the yogurt. Adding protein drinks, or "shakes" can thicken yogurt without using full fat or adding instant powdered milks. Adding 1-2 of these 11oz shakes to a fat free milk can help make a very thick yogurt while adding flavor and keeping the sugar very low.

Can I use this method with other Ultra Pasteurized milks?
For the most part, yes. Sometimes the high heat process damages the proteins in the milk to the point that it won't set. Some UP milks take longer to incubate, up to 10 hours or more. Milks that you can try for the cold start method are: Organic milks, Soy milk, canned milks (evaporated or sweetened condensed), heavy cream, half & half, powdered milk (mixed with filtered water), any ultra pasteurized or ultra high temp milks.
You will need to keep in mind that Fairlife milk has more protein, which helps make a thicker yogurt. Higher fat and more protein is what makes whole milk yogurt thicker than a1% or non fat milk yogurt. 

Why is milk heated to make yogurt?
Three reasons:
1. Kill pathogenic (harmful) bacteria. If raw milk is used, heating it kills bacteria. The higher you heat the milk, the more bacteria is killed. Heating milk to 160°F is pasteurization.
2. Allow only yogurt bacteria to grow. Yogurt bacteria begin to grow in a 100°F-110°F environment. So milk is heated to at least this temperature to allow the yogurt bacteria to begin doing their work.
3. Change proteins. The proteins in the milk begin to change, or denature, when the milk is heated. The higher the temperature of your milk, the more the proteins will denature. This process results in a thicker, more custard-like yogurt.
Ultra pasteurized milks have already been heated to 280°F, so no pre-heating is necessary.

Can I heat my regular pasteurized milk and Cold Start it later?
No. You would have to heat your milk to at least 280°F, which can foam, scorch and burn. Heating it only to 180°F would not be enough to use it for Cold Start yogurt, for the reasons listed above. You can read more about ultra pasteurization in the next question.

Are Ultra Filtered & Ultra Pasteurized the same thing?
No. Ultra filtered milks are milks that are screened, or filtered, to separate the milk components of water, fat, sugar, lactose, etc. and are put back together. Low fat milks use a similar process. Ultra filtered milks need to use the traditional boil method and cannot use the Cold Start.
Ultra pasteurized milks are heated to 280°F, quickly cooled and are 99.9% bacteria free. These milks are suitable for the Cold Start method because they are heated for a thicker yogurt and are bacteria free.

Do I have to use Fairlife Milk?
No. You can use any ultra pasteurized, ultra high temp (UHT), or shelf stable milks which include: canned, boxed or powdered milks. Many use Fairlife milk as it helps make a much thicker yogurt that doesn't need straining. This is because it has more protein than other ultra pasteurized milks.

What is Fairlife milk?
 It is 100% dairy milk that filtered, using a process similar to water filteration, by using sieves, adsorption, ion exchanges and other processes, resulting in a milk that has 50% less sugar, 50% more protein, 30% more calcium and is labeled as lactose free.  Fairlife milk  comes from Fair Oaks Farms in Indiana. Coca Cola does not own Fairlife; it has a partnership with Fair Oaks Farms, handling the marketing and distribution. You can find a list of 74+ stores that carry Fairlife here.

Is Fairlife milk Ultra Pasteurized? 
Yes, Fairlife milk is ultra pasteurized.
It doesn't say it on the carton, so I contacted Fairlife, and this is the response I received:

Can I use any Lactose free milk? How does lactose work?
Yes. Most lactose free milks are ultra pasteurized and work well. Fairlife milk is lactose free.  Lactase is added to the milk to make it "lactose free.":

"Those who are lactose intolerant are not allergic to milk, or even to lactose. Instead, they lack the digestive enzyme needed to break down the lactose, or the sugar in milk.
"Lactose-free milks are the same as regular milk, except for the addition of lactase. This neutralizes the lactose and, therefore, eliminates the gastrointestinal trauma. Lactase does make milk taste sweeter. Also, to neutralize the lactase enzyme inactive, manufacturers ultra-pasteurize the milk, a move that extends the shelf life." - Karen Fernau, Food writer 
Here is another explanation of lactose free milk:
"It’s neither practical nor really possible to remove lactose from milk — not only would it be logistically difficult, it’s simply not necessary. Instead, manufacturers react the lactose chemically, altering its composition and converting it into molecules that your digestive system processes easily. To react lactose, manufacturers add small amounts of the enzyme lactase to milk, explains OrganicMeadow.com, a producer of lactose-free milk. The lactase splits lactose into its constituent components, which are two sugars called glucose and galactose." - How is Lactose Free Milk Made?

But wait...don't you need lactose to make yogurt?
There are two things at work when making yogurt with lactose free milk. First, the lactose free milk is treated with the lactase enzyme to break down the lactose into its component molecules, glucose and galactose, which make it easier for the bacteria to ferment. Otherwise, they do this conversion themselves, but the process is a bit slower.

Second, the ultra filtered milk is higher in protein, and the action of the bacterial fermentation creating lactic acid which then acts to coagulate the protein. More protein, easier coagulation. -Kathy Peschell

Do I have to use a non-dairy yogurt with Lactose Free milk?
No. You can still use a dairy yogurt as your starter! The lactase added to lactose free milks will help you digest any lactose that is found in your starter. If you want to use a dairy free yogurt as your starter, you can use a dairy free yogurt: Silk,  SoDelicious, or try Yogurmet, a freeze dried powdered starter.

Can I use Low Fat milk?
Yes, you can use low fat or skim milk for for making yogurt with the cold start method.
Lower fat milks have a higher water content and may yield a more soft-set, pudding like yogurt. If you want a thicker yogurt, you may want to strain or add non-fat instant powdered milk your yogurt for a thicker consistency. Fairlife, Joyya and similar low fat & skim milks have more protein, which help contribute to a much thicker yogurt than other milks.

It is not necessary to use a low fat yogurt starter with these milks - you only want the starter for the live cultures. You can find out more about How to Choose a Starter, here.

Can I use Chocolate milk or a flavored milk?

Fairlife Chocolate milk, like any store bought chocolate milk, has too many additives (thickeners, sugars and other ingredients) that interfere with the culturing process.  Most people using Fairlife and other chocolate milks get a thin, "pudding-like" texture, even with a 9 -10 hour culturing time. Some add sweetened condensed milk, which does help thicken a little bit, but adds sugar to an already sweet milk. The additional sugars in the milk will need at least a 10 hour culturing time, which makes a tangy or tart yogurt. For most people, this combination of chocolate + tartness is not a pleasant taste. If you want a chocolate yogurt, make a plain yogurt, and after chilling, add chocolate syrup, chocolate drink mix powder, whey protein powder or a small box of instant pudding mix.

How can I make a DAIRY FREE cold start yogurt?
If you need a dairy free option, Soy or Ripple (pea) milk work great!
TIP: Soy or pea milks need at least 12 hours incubation to thicken and will continue to thicken or "set" while chilling in the fridge. It will not be a thick Greek style yogurt, but more of a traditional yogurt consistency. 

These are the only plant based milks that don't need a thickener.

Almond, Coconut, Rice and other plant based milks need a thickening agent (gelatin, agar agar, tapioca starch, etc) and those thickeners require heat to activate. These milks will not work well for the cold start method.

Does the Cold Start™ method save any time?
Yes, it can! It only takes 2-3 minutes to mix up your milks, push the yogurt incubation setting, and walk away. Most find that they don't need to strain, which saves 4-8 hours.

Is it safe to make yogurt with this method?

Yes. I have tested the temperatures of the milk in my testing and found that the Instant Pot yogurt setting warms up the milk to 107°F within 30 minutes, well within food safety guidelines. The Unsafe Food Zone temperature range is 40°F-140°F as determined by the USDA.

The Unsafe Food Zone
The unsafe food zone is any food that is left out in the temp range of 40°F-140°F for 2 hours or more. It is perfectly fine for any milk to be in the unsafe food zone as long as the yogurt starter is actively working in the milk. Once the yogurt starter is active (in the 100°-110° range), it begins to produce acidic whey, which continues to ferment and preserve your milk in this temp range. Milk without an active yogurt bacteria present should not be left out at room temperature for 2 hours or more.

UP/UHT (ultra pasteurized/ultra high temp) milk already has 99.9% of the bacteria killed during processing, meaning there is little risk, if any, of any pathogenic (bad) bacteria multiplying during the warming up to the incubation zone, as long as it is less than 2 hours. Once you open UP/UHT (ultra pasteurized/ultra high temp) milks, it needs to be treated like dairy milk. Even though UP/UHT milks are shelf stable in their sterile packaging for 6+ months, once opened, their fridge shelf life is 1-2 weeks and should not be left open at room temperature for more than 2 hours.

You should not try the Cold Start™ method with raw or regular pasteurized milk. See below.

*If you are undecided about the safety of using the Cold Start™ method, you can always warm up your yogurt to 100°-110°F, add your starter and incubate from there.

Can I use the Cold Start™ method with regular pasteurized milk?
I do not recommend using the Cold Start™ method with regular pasteurized milk. Even though the milk is heated to 160°F for pasteurization, there are still natural bacteria present in the milk. This bacteria can grow/multiply during the 30-40 minutes of warming up to incubation temp & compete with the natural bacteria in the yogurt starter. This competition of bacterial strains may result in either a thin, runny yogurt, lumpy, bitter, stringy or ropey yogurt. You can see the results of what happened with raw milk:
Raw milk used with the Cold Start™ method
For raw, pasteurized & filtered milks,  you can find this simple method here for thick, Greek style yogurt.

How do I sweeten or flavor the yogurt and when do I add it?
If you want a vanilla yogurt, you can add your vanilla extract when your yogurt has chilled and strained. It is theorized that the alcohol from the extract can interfere with the culturing process, but you can add vanilla bean paste or scrape a 2"vanilla bean into your milk before starting. If you are straining your yogurt, any flavor or sweetener can go out with the whey.

Sweetener, Added AFTER CHILLING:
You can use any sweetener of your choice after your yogurt has chilled and strained. Granulated sugar, powder sugar, maple syrup, or any alternative sweetener can be used. Honey mixes in better if it is warmed first.  If you add sugars to your milk prior to heating, it can inhibit, or slow down the culturing process, adding time to your yogurt to properly set. I prefer to add sweetener after my yogurt has finished. You can add a small box of instant pudding, coffee, drink mix, or get some inspiration from this topic in my Instant Pot Yogurt Guide for Newbies.

Sweetened Condensed Milk, Protein Drinks, Creamers, Added to the milk BEFORE incubating:
You can add a up to small can of sweetened condensed milk to your Fairlife milk prior to heating. Make sure it is mixed in well and plan to add time if necessary to allow your yogurt to gel, or set. This makes a creamy, slightly sweet vanilla yogurt.

Can I mix the milk & starter together and pour them into individual jars first?
If you are not straining your yogurt and like the consistency, you can try it. Fairlife and other filtered milks will make a yogurt that has the thickness between Greek and traditional yogurts. You can use canning jars or Oui yogurt jars.

When 2 layers of jars are used, the bottom jars will set while the top layer is still liquid milk. It can take at least 10 hours to for the top layer to set. No trivet/metal rack or lids are necessary. You can add 1"-2" of water, which seem to help incubate the yogurt, but it is not required.

Does the texture change with this method?
No. If you use whole milk, it will taste creamier. You can use 2% or skim, and have it strained nice and thick, but the texture may not be as creamy. If you like the taste of the milk, you'll enjoy the yogurt made with it.

Why is my yogurt grainy or gritty?
 The yogurt stuck on the bottom of the pot does have a gritty or grainy texture. Take a look at the photo, below, taken right after incubation and before straining in the fridge. Avoid scraping this into your yogurt. This may be difficult to avoid if you chill your yogurt while in the pot prior to straining.

Try slowly pouring your yogurt immediately into another bowl or your lined strainer and chill in the fridge or use the Ice Cube tip in my traditional yogurt recipe, which keeps the milk from sticking to the bottom of the pot. If you still find your yogurt to have a grainy texture, try another brand of yogurt as your starter. Each brand of yogurt has a unique blend of bacterial strains that make up both the tang & texture of your yogurt.

The yogurt stuck to the bottom of the pot had a grainy, gritty texture. When using the ice cubes, this is how my pot looked after milk was heated.


  1. I made the cold start yogurt 3 times and it turned out great! Made it as your instructions, with the sweetened condensed milk. Didn't make it for months and now tried it 2 times and it never set. Used exactly the same ingredients and it did not set, don't know what I did wrong? Any suggestions?

    1. There are two possibilities. One, you may have had your yogurt on the Low/Less setting, or two, your starter was weak or inactive. If this happens again, check your settings and/or try adding a couple of extra hours for incubating. If that doesn't help, test the temp of your yogurt setting. This can be done by using 4 cups of water, select your yogurt incubation setting (Normal/Medium/Custom), wait 30 minutes and test the temp of the water. It should be in the 100°-110°F range. :-)

  2. Hope much does this recipe make?

    1. It depends on how much milk, the milk percentage, you use and if you strain it for a thicker yogurt. You can halve the recipe, or double it if you wish. You can find the complete recipe here. :-)

  3. I have a pretty new IP and have only made yogurt about 4 times. The first 2 times I used fat free Fairlife milk with yogurt I bought. The last time I used Fairlife fat free milk and used yogurt I had frozen from my previous batch as a starter and it came out fine. Today I used Simply Nature Organic ultr-pasturized fat free milk with 8g of protein with more of the frozen yogurt I had saved to use as a starter and after 8 hours I ended up with warm milk. Why would that happen and is there anything I can do to fix it or is it a loss? thank you

    1. Some ultra pasteurized milks can take up to 10 hours to culture, or set. If it doesn't set up or show any signs of thickening by the 10th hour, I'd toss it. If it shows some evidence of thickening, you can use the thin yogurt in smoothies or frozen yogurt pops. You can also check my troubleshooting section of my Yogurt Guide for additional information. :-)

  4. My FairLife whole milk bottle lists as an ingredient "lactase enzyme" even though the bottle is labeled "lactose free." And it does not mention "ultra pasteurized" even though you said they wrote to you saying that it is ultra pasteurized. I love their milk products but wonder about the integrity of their labeling.

    1. Hi David -
      All lactose free milk contains lactase. You can read in my article above how this works in milk to make it "lactose free." I, too, was confused about this. I do agree that there should be something on the label that states the milk is ultra pasteurized. That would be helpful, as folks get that confused with "ultra filtered," which is a totally different process. πŸ™‚

  5. Frieda: If I use a freeze dried starter to your cold start with one container of Fairlife (red) and a can of sweetened condensed milk as per your recipe would one packet be enough? Thank you in advance

    1. Check the directions on the box. The brand I'm familiar with uses one 5g packet with every liter or quart of milk.πŸ™‚

  6. I want to make the frozen yogurt. I read the Cherry Garcia recipe. The question I have is: do I need to strain the yogurt or can I use it the way it is after the 4-6 hours in the refrigerator. I am doing the cold start method with the condensed milk, 1% Fairlife, and 0% Fage for the starter.

    1. With 1% milk, you will want to strain it for a creamier texture. If you don't strain, the texture will be more icy and closer to a popsicle. For best results with frozen yogurt, I recommend using a full fat yogurt.

  7. Can I freeze the yogurt I use as a starter instead of wasting the rest of the container?

    1. Absolutely. Freeze the tast of yout yogurt asap from opening in tablespoon portions. I like to use an ice cube tray. Transfer frozen starters to a freezer baggie and they will keep viable for up to six months.
      You can find many more answers to questions about yogurt in my Instant Pot Yogurt for Newbies Guide. πŸ™‚

  8. Can I use the non-stick pot instead of the stainless? Can I put the milk (for cold start) in a smaller pot inside the 8 quart pot so that it won't take up as much room in my fridge? Will that effect the timing?

  9. You can use your ceramic insert for making yogurt. You can use PIP (pot in pot)style by putting jars or food safe bowl inside your insert. You may want to add 1"-2" of water to the insert if you use PIP. You can slowly pour your warm yogurt into s strainer or smaller container that fits in your fridge. No scooping or stirring until your yogurt has fully chilled. πŸ™‚

    1. If I use the pot in pot method, do I place the pot on a trivet with the water underneath or just set the pot in the water?

  10. Thanks. I think I will try the PIP method. I haven't made yogurt before and I am afraid of breaking up the yogurt by transferring it before it chills. If it is very thick from the start, that is if it passes the spoon test, will it pour?

    1. Most spoon test pictures you see are after yogurt has chilled. Please watch my other video of making boil method yogurt and you can watch me pour my warm yogurt into a strainer. It will break up into large chunks, but that is ok. Stirring your warm yogurt is not ok. You'll do great!πŸ™‚

  11. After you strain the yogurt, if you transfer it to another container will it lose its consistency/thickness?

  12. I love your cold start yogurt recipe. Will never go back. Make it often. Yesterday I tried in small yogurt jars in my IP. Only the bottom ones set up. Today I did the top row for 4 more hours and they set up. Can I only do one layer at a time? Would appreciate your advice.

    1. Most folks incubate both layers of jars for a total of 10 hours, which gives additional time for the top layer to set.
      You can incubate one layer at a time, providing you are incubating as soon as you mix the milk & starter. πŸ™‚

  13. I use fairlife 1% and vanilla oui yogurt, but then need to strain it. Leaving me with a lot less yogurt. How much instant milk powder should I use to get it thicker? I sweeten after with mio drink flavors, and use some in place of sour cream.

    1. Low fat milks have a higher water content and Fairlife will still give you a thicker yogurt than its counterparts due to its high protein. Try adding 1/3-1/2 cup instant powdered milk mixed into your cold milk to start. πŸ™‚

  14. You don't mention using the Instant Pot glass lid. Is it ok to use it since I have one? Thanks!

    1. You most certainly can use the Instant Pot glass lid for making yogurt. Any lid from your pots,pans, dinner plate, pie plate or silicone suction lid will work as well.πŸ™‚

  15. Hi Frieda! I used the cold start Message with oat milk and oat yogurt. I let it sit in me instant pot for 12 hours and refrigerated it but it's still all liquid. Can I save this anyway?

    1. I'm sorry, but the only plant based milks you can use with my Cold Start yogurt recipe are soy or Ripple pea milks.
      All other plant based milks need a thickener (gelatin, tapioca, agar,etc) and the boil method to work. I'm not sure you can save this batch. Sorry!

  16. Can you just stir the whey back in or do you have to strain it out?

    1. Straining is optional and depends on how thick you like your yogurt. If you do strain,and it's too thick, you can whisk some whey back in to your desired consistency. πŸ™‚


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