A yogurt starter culture is a balanced blend of lactose consuming bacteria that is ready to start converting the lactose in milk into lactic acid. The lactic acid is what gives yogurt its tangy deliciousness.
The lactic acid also lowers the pH of the milk, serving both to preserve it and changing its protein structure to change the texture of the milk into yogurt. Different yogurt starters have different blends of bacteria that activate at different temperatures and grow differently, creating a variety of flavors and textures in the finished yogurt.
There is no “best yogurt starter”, but the best culture for your uses will depend on your own needs and preferences. Even within categories of yogurt, different cultures are sweeter or thicker or more reliable. Let’s take a look at some of the common differences you’ll notice between different yogurt cultures.
One way we separate yogurt starters is by the temperature that they multiply at. Thermophilic cultures love heat. These yogurt cultures are added to heated milk and culture for hours at a higher temperature. They require a constant heat source and are usually made in some sort of yogurt maker.
Mesophilic starters, on the other hand, propagate well at room temperature, around 70-77 degrees fahrenheit. With no need to preheat the milk and no special heat source needed, mesophilic yogurt starters are easy to culture, but tend to produce thinner yogurt while thermophilic starters tend to create a thicker yogurt.
Direct set yogurt starters are single use starters. They’re added to milk to create a single batch of yogurt. With some care, directe set cultures can sometimes be recultured 2 or 3 times before they lose their effectiveness and a new powdered starter must be used.
Heirloom yogurt cultures, on the other hand, can be propagated indefinitely. Just save a little of the yogurt from the last batch to add to the next batch and they’ll reliably make yogurt over and over. You just have to make sure to keep making new batches of yogurt, usually at least once a week, to keep the starter healthy.
Well, the best thing to use as a yogurt starter is a good yogurt starter culture! Some kinds of commercially available yogurts have live bacteria and can be recultured by adding a spoonful of store bought yogurt to milk. However for that to work, you’ll have to make sure to get a yogurt with a live yogurt culture, then culture it correctly for that particular strain of yogurt, and most commercially available yogurts will end up operating like direct set cultures where you can reculture them a couple of times with some success before you’ll need to buy more yogurt. As a result, we find that more people have a better experience culturing yogurt from a real yogurt starter.
If you’re culturing an heirloom yogurt, a spoonful of that yogurt makes a great yogurt starter. You can even give friends a cup of yogurt to start their own cultures. You can also carefully dehydrate heirloom yogurts at low temperatures and usually successfully wake them back up with milk.
There is no “best yogurt starter”, but there are some common ones people love. Our Bulgarian yogurt starter is a common thermophilic heirloom yogurt culture that produces yogurt very similar to common store bought yogurts. And our heirloom yogurt starter cultures bundle is a great collection of several varieties of mesophilic heirloom yogurt starters. These yogurts all culture at room temperature and this bundle gives you several varieties to try out!
There are several ways to attempt to culture yogurt without a starter culture. In fact, yogurt likely originated from some ancient person’s milk spoiling in a way that they liked. However, give the pitfalls inherent to letting milk spoil, we’d highly recommend starting with a reliable starter culture.