What is yogurt?
Yogurt is made using two main ingredients: milk and lactic acid bacteria. These bacteria are essential to convert milk into yogurt. Yogurt manufacturers also add condensed milk or powdered milk to achieve a firmer yogurt. Stabilizers such as gelatin, starch, pectin and other gelling agents (guar gum or locust bean gum) are added to ensure the whey does not separate from the yogurt and form a yellowish layer of liquid on the surface. The list of ingredients more or less stops there for plain yogurt. Sugar and fruit are added to flavoured yogurt, as well as fruit essences and food colouring.
Good bacteria
There’s been a lot of talk lately about “probiotic” bacteria that are beneficial to intestinal tract health. The types of probiotic that provide the most benefits are Bifidobacterium (or bifidus), Lactobacillus acidophilus and Lactobacillus casei. Look for “contains live and active cultures” on the yogurt label. In order to be effective, this type of yogurt must be eaten regularly and not cooked as heat destroys the bacteria.
Cooking with yogurt
Yogurt can replace milk, buttermilk, sour cream and even cream cheese in many of your recipes.
Yogurt can replace milk in muffins, cakes and scones
Plain yogurt can replace buttermilk, volume for volume, without any other specific changes. It can also replace milk, volume for volume, but since yogurt is thicker, dilute it with a bit of water or milk before measuring.
Yogurt can replace cream cheese
Yogurt can be used instead of cream cheese in dip, spread and cheesecake recipes. However, you have to strain it first to convert the yogurt into “yogurt cheese.” (The how-to technique is listed below.) The resulting cheese looks like cream cheese, but contains a lot less fat. Substitute it volume for volume in recipes that call for cream cheese.
Yogurt in sauces and hot dishes
Yogurt can replace crème fraîche, cream or sour cream in sauces or dishes such as Beef Stroganoff, but you have to add a bit of cornstarch to stabilize it first. There is one hurdle to overcome: yogurt forms small, annoying lumps when it is cooked and this makes sauce look curdled. Proteins are already fragile due to the presence of lactic acid in the yogurt. They begin to clump together and form lumps when exposed to heat. This phenomenon does not affect cream or sour cream because, unlike yogurt, they contain very little protein and a lot more fat. Fat helps keep proteins separated from one another and prevents them from clumping together to form lumps. Cornstarch contains large, bulky molecules which are great for blocking interaction between yogurt proteins.
Techniques
Here are three techniques to stabilize yogurt in sauce.
- You can thicken the recipe by adding cornstarch (or flour) before adding yogurt.
- You can mix cornstarch with yogurt before adding it to the recipe. Dissolve 10 ml (2 tsp.) of cornstarch in 75 ml (1/3 cup) of water and bring it to a boil in the microwave or while stirring on the stovetop. The mixture, or paste, will be very thick... this is normal. Make sure to mix the heated paste thoroughly with the yogurt before adding it to your recipe. This amount of paste is sufficient to stabilize 180 to 250 ml (3/4 to 1 cup) of yogurt.
- You can also add yogurt directly to a recipe such as the sauce for Beef Stroganoff, for example. It is important to warm the yogurt slowly by adding a bit of the heated sauce and then stirring in the rest of the sauce.
