What temperature to set yogurt?
Once your milk and starter are combined, all that's left is to keep the yogurt at a steady temperature (110°F to 115°F), undisturbed, for 5 to 10 hours, which allows the good bacteria to flourish.
Therefore, to make nice thick yogurt you must incubate it, maintaining it in a temperature range between 110° and 115°F/43° and 46°C. Incubation strategies, the most challenging aspect of making yogurt (and some other ferments), are covered in chapter 3. To make yogurt, you need a starter culture.
- When yogurt is frozen then thawed, it can separate and become grainy and watery. The yogurt may also take on an acidic taste and some of the live bacterial cultures abundant in natural yogurt may be destroyed by the freezing process. However, thawed yogurt is still healthy to eat.
- The temperature needed for fermentation must be between 25°C and 50°C. If the temperature is too low, the yeast will be inactive. If it is too high, the enzymes in the yeast will be denatured and will stop working. Air must be excluded from the container where fermentation is being carried out.
- Other fluids which are good options during cold and flu infection include:
- Ginger ale;
- Herbal tea;
- Honey and lemon tea – mix lemon and honey with a cup of hot water;
- Ginger tea.
(Note: The yogurt bacteria can be killed if exposed to temperatures above 130 degrees F, so be careful not to add milk that is too hot!) Place the jars in a cooler and seal it. Quickly heat up about one gallon (3.8 liters) of water until it is at 122 degrees F (50 degrees C).
- When your milk has reached 115°F, place the plain yogurt (the starter) in a medium bowl or glass measuring cup, using 2 tablespoons yogurt for ½ gallon milk or ¼ cup yogurt for a gallon of milk. Ladle in roughly 1 cup of the warm milk and whisk to combine. (This is called tempering.)
- No, but it's complicated. While the heat from cooking and pasteurization can easily destroy enzymes and probiotics, there is evidence that heat-killed probiotics can produce similar results to live probiotics. In a study done in 2009, heat-killed bacteria was found to improve intestinal and organ inflammation.
- Sweeten it up!
- Add a spoonful of jam or fresh fruit to replicate popular commercial yogurts. Start with 1 tablespoon per cup and adjust to taste.
- Add Sugar, honey, maple syrup or any other sweetener to taste.
- Flavor extracts. Add 2-3 drops of extract per cup of yogurt and adjust to taste.
(You can learn more about How Long Cultures Last here.) Once you've activated the starter culture and started making yogurt, your homemade yogurt is generally good for eating for up to 2 weeks, when stored in the refrigerator. For re-culturing, we recommend using the yogurt within 7 days to make a new batch.
- Protect yogurt from other foods with strong odours by sealing it tightly. Spoon as much yogurt as you are going to eat into your bowl with a clean spoon. To avoid cross-contamination (which will speed up spoilage), do not return unused portions to the original container. Do not freeze yogurt.
- Baked goods will rise well when yogurt is used due its acidity. It can be used with excellent success in baked goods, using it as part of the liquid in cakes, waffles, pancakes and muffins. Yogurt is an excellent dish by itself, but can also be used in place of sour cream.
- Incubated at 115°F/46°C, yogurt will coagulate within about three hours, but if left too long it can easily curdle. I have heard of people fermenting yogurt for as long as 24 hours. At lower temperatures, coagulation will take longer, and the end result will probably not be quite as thick.
Updated: 16th October 2019