Homemade Yogurt Recipe
I am often asked to share my yogurt recipe, so it’s high time that it end up on the website! Making yogurt at home is far more economical, and I am convinced more beneficial health-wise, than buying it by the quart. For example, a decent brand of natural (not necessarily organic) yogurt at the store will cost at least 3 or 4 dollars. Organics/grassfed can be even more. But if you’re using top quality raw milk purchased for as much as $10/gallon, one quart of homemade yogurt will still only cost you $2.50 plus time, a little electricity, and a one-time purchase of a good starter. If you follow these tips, you can keep your homemade yogurt going indefinitely. Have fun!
My method has been developed for whole raw milk. Use pasteurized milk at your own risk. I don’t know how it would do, but I imagine it would be fine if you include the scald step. I also don’t know how skim milk would turn out, but I suppose if it is fresh, it should work fine.
Basic Yogurt Method
I have never had “raw” yogurt turn out well. It’s runny, stringy, tastes weird, or molds early. So I scald my milk prior to inoculation.
1. Scald milk to 180F.
Place milk in heavy-bottomed pan, cover, and heat until it reaches 180F. This temperature disables the live strains of bacteria present in the milk so you can get a reliable result. If you want to stir it constantly, you can heat it faster over high heat. If you wish to do a more hands-off (aka lazy) approach like me, use medium-low and use a clean probe thermometer with an alarm to notify you when the milk reaches temperature. Just don’t forget about it and go on a shopping trip.
As soon as the milk hits 180, turn it off and cover it tightly to keep air contaminants out.
2. Cool milk to below 115, but not below 105.
I’m lazy and just leave the pot sitting (COVERED) until it gets to a cool enough temperature not to kill my starter. If you wish to speed this process, you can place the pot in the sink in a cold water or ice bath. If you accidentally cool it below 105, heat it back up, taking care to use clean utensils so you don’t contaminate the scalded milk.
The milk will likely have a yellow skin across the top. I suspect it is there because of evaporation during the heating process. I don’t worry about this at all. We’ll deal with it later. Just ignore it and proceed as usual.
3. Inoculate (aka add starter).
In a medium bowl, whisk together a portion of hot milk that is about equal to the amount of starter you are using. Mix until smooth, then stir into the larger container of cooled, scalded milk.
DO NOT use the starter to cool the scalded milk. You must keep the live bacteria alive in order for the starter to do its job. The milk MUST be within the temperature range of 105-115 to ferment properly. If it is too hot, you will kill your starter. If it is too cool, the milk will stay milk or possibly grow an unfavorable strain (more akin to buttermilk) and turn out thin and non-yogurt-like. Heat it back up if necessary, but if you’ve already added the starter, take care not to overheat it. Keep in mind the TOP of the milk will be cooler than the BOTTOM of the milk in the pot. If you stir adequately, the temps will be closer to the same and give you a more adequate temperature reading.
Move the inoculated milk to chosen lidded containers and place in insulated area for up to 30 hours (we like 24 hours).
The idea here is to keep the inoculated milk within the ideal temperature range for 6-30 hours and to eliminate exposure to contaminants during this time. The longer the ferment, the more lactose will be consumed and the more beneficial bacteria and byproducts present in the final product. There are lots of ways to do this.
Containers: You can use the pot you scalded the milk in or transfer it to VERY CLEAN containers such as a glass crock, plastic tubs, glass jars, etc.
Insulation: Slightly warm oven, plastic cooler with hot water bath, or electric dehydrator set to 110F (this is certainly the easiest). Whatever you use, remember that you’re going for very hot shower temperature, and it needs to stay there for the duration of fermentation, so feel free to periodically turn the oven on again or add more hot water to the cooler.
You may find that after 24 hours of sitting, the milk will developed a slight cream layer. We like this mixed back into the entire batch of yogurt. The easiest way to accomplish this with a very large batch of yogurt is to use an immersion blender. Or use a whisk and stir vigorously to break up the cream chunks and mix them into the body of the ferment. This is not a required step, but it does make a more pleasant and evenly distributed final texture. I do not find that the yogurt separates again after it is cooled.
If you wish to save your own starter, do that at this stage.
My favorite storage container is a large glass crock or large glass jar. Plastic tubs work well, too, but not for long-term storage, as plastic is porous and tends to hang on to mold spores, causing mold contamination. I find that a good clean glass container keeps the yogurt fresh for 6 weeks in a cold fridge.
Saving your own yogurt starter is very simple, but it must be done before the live bacteria get old and tired. I learned this the hard way after having multiple batches fail because I was using 6-week-old yogurt to try to inoculate my new batch.
To save starter successfully, separate the portion you wish to keep as starter and freeze it immediately after fermentation. Freezing in plastic works fine for me and eliminates the possibility of glass jar breakage. You could also freeze starter in ice cube trays and then pop them into a larger freezer container. This is ideal for those making smaller batches of yogurt.
When you’re ready to make your next batch of yogurt, simply thaw the amount of starter needed.
It’s not a bad idea to always keep extra starter from a successful batch of yogurt just in case you mess up your current batch. Never save starter from a batch that is below par. It will only turn out worse.
Where to buy your first starter
At your local health food store! I like the White Mountain Bulgarian style yogurt the best, but have had success with Dannon Plain and other live yogurts. Do not use flavored yogurt or any plain variety that has thickeners added. The label should say something about live bacteria or L. Bacillus etc.
Strategy in summary:
- Scald milk at 180F.
- Cool to range 115F-105F.
- Add starter. Use about 1 cup starter per gallon of milk.
- Fermented in temp range of 105F-115F for 6-30 hours, preferably at least 24.
- (Optional) Mix cream layer back into yogurt.
- Save starter right away by freezing. Glass containers provide the longest storage of to-eat yogurt. Plastic containers are fine for freezing starter.