A common question we get asked about yogurt making is? “Why is my yogurt runny?” or the flipside “How can I thicken my yogurt?”. I’m going to make you sweat on the answer for just a second because I first want to reassure you that there is NOTHING wrong with eating runny yogurt. Yogurt can be anything from drinkable to thick and creamy and it is still a beneficial probiotic food source regardless of where it is on this spectrum.
Having said that, I do understand the visceral appeal of thick, voluptuous yogurt and if thickening it up still calls to you, then keep reading. We have four simple tips below. First though, I’ll run through some trouble shooting fundamentals to help with you yogurt making.
Temperature and time both play a huge part in the outcome of tub-set yogurt. Unless you live in India or other similarly warm climates you’ll have no chance of incubating milk into yogurt at a stable temperature for 24 hours. Bacteria remain dormant below 36 degrees Celsius and in Melbourne right now, it’s 14 degrees outside! While milk can be fermented into yogurt in just 6-8 hours, we favour 24 hours for a therapeutic grade, probiotic yogurt and that is hard to accommodate without the right gear.
There are lots of DIY ways to incubate milk (an oven, a slow cooker) but they are all flawed when it comes to keeping an even temperature for 24 hours. Too hot or too cool will negatively impact the bacteria in your yogurt starter culture. You really need a yogurt maker. A possible cause of runny yogurt is the bacteria fermentation slowing down, becoming dormant or being killed by an uneven heat source. Fermenting for longer always results in a thicker yogurt anyway.
Before you start making yogurt, consider the milk that you use. Dairy manufacturing methods effect the structure of milk and this changes the consistency of yogurt. We suggest you experiment with different brands to find the one that produces the consistency you like most. Milk with a high fat content will definitely give you a thicker, creamier yogurt.
Because we want you to benefit from the most therapeutic homemade yogurt, we recommend organic milk. Hormones and antibiotics found in conventional milk may interfere with fermentation. Any milk that has been altered beyond simple pasteurization and homogenization - such as skim, lite, lactose-free, lactose-reduced or milk with additives such as omegas - will not make good yogurt. Raw milk that has come straight from a cow and is free from processing (pasteurisation and homogenisation) will always result in a thinner finished yogurt.
Different yogurt starters result in different yogurt consistencies. We recommend you follow the handling and storage instructions unique to your culture (or probiotic) so that the strains stay fresh and active.
If you inoculate milk with a portion of homemade yogurt (as a starter to re-culture) make sure you do not continue this process indefinitely because the strains may be too few or too weak. If you are using store-bought yogurt as a starter, be sure not to choose a brand that contains thickening agents as they sometimes interfere with re-culturing.
Heating denatures the proteins in milk and encourages the proteins to coagulate and thicken. When preparing the milk, gently heat it to 160º-180°F, (71°-82°C) and maintain the temperature for 20 to 30 minutes. This can be a complicated and stressful task depending on your stove top. To ensure a continuous, pre-boil temperature, I use a wok ring to create a distance between the flame and pot. A double boiler pot will do the same thing.
Straining the yogurt removes some of the water content (whey), leaving the fats and proteins behind. The longer you drain away whey, the thicker your yogurt will become. Removing all the whey will result in a thick probiotic yogurt cream cheese.
It’s the fat in animal milk yogurt that helps to make yogurt thick and creamy. When making yogurt it is possible to substitute a portion of the milk with pure raw cream. Pure cream is an ideal thickening ingredient when making raw milk yogurt. The steps for making raw milk yogurt and cultured cream (sour cream, crème fraiche) are the same.
From a gut health perspective, we love the benefits of adding a premium powdered gelatin to homemade yogurt. Add 1 teaspoon of gelatin to every 4 cups of cold milk before heating and culturing. Gelatin must be heated to at least 95⁰F (35⁰C) to activate. It can be heated beyond this temperature, but it must never boil. Tip: Gelatin can be tricky to whisk into a large quantity of milk without clumps forming. To integrate more easily, expand the gelatin in a smaller quantity of milk first. Simply pour half a cup of milk into a small bowl, add the gelatin and mix thoroughly. Leave the gelatin mixture to sit for a few minutes to swell then transfer the swollen gelatin into the rest of your milk. As soon as the milk is heated, the clump of gelatin will quickly dissolve.
Coming soon: How to thicken non-dairy yogurt