The genesis of yogurt was likely accidental: Historians envision a serendipitous union of raw goat’s, sheep’s, or cow’s milk and wild bacteria, left by happenstance to sour in the hot sun. The tart and creamy living food tasted great, kept longer without refrigeration than fresh milk, and could be consumed in many ways.
That yogurt was a far cry from today’s commercial offerings. If you want full control over the finished product—pure, undoctored cultured dairy of the highest quality (no stabilizers, sweeteners, or additives)—as well as the ability to control the fat content, sourness level, and consistency, consider making yogurt at home.
Our streamlined process demands little effort, just time, and our ingredient recommendations and oven incubation setup (as well as our sous vide variation) guarantee a milky, silky delight. Along the way, you’ll be rewarded with the satisfaction (and fun!) of witnessing natural fermentation.
What You’ll Need
Ultra-pasteurized milk leads to yogurt with a thick, uniform texture; it also saves time and effort. To understand, look at the usual first step in yogurt making: heating milk to 160 degrees or above. Along with killing unwanted microbes, this changes the milk’s protein structure and gives the yogurt body. The scalding temperature affects the consistency of the final product. Lower temperatures produce a runnier gel, while higher ones make a thicker gel but can lead to separate curds and lots of whey if some of the proteins overcook. The ideal creamy, homogeneous texture is achieved when the milk is given only a very short, uniform exposure to high heat—which, as it happens, is how ultra-pasteurized milk is treated: It’s heated to 275 degrees for less than 5 seconds and then rapidly chilled.
Store-bought Plain Yogurt
Use any commercial yogurt made with live, active cultures to initiate fermentation. Streptococcus thermophilus and Lactobacillus delbrueckii subspecies bulgaricus are the two (symbiotic) species of lactic acid bacteria mandated by the U.S. Food and Drug Administration because they “characterize yogurt”; almost all yogurts also contain other species and strains.
You’ll need two 1-quart glass Mason jars with metal lids to contain the yogurt while it incubates in hot water; one large saucepan; and two large pots (one with a lid) that will fit in your oven at the same time. A funnel is helpful for transferring the yogurt to the jars.
How to Customize
Making yogurt that you’ll love begins with choosing a starter yogurt that you enjoy. Any variety (whole milk, Greek, Icelandic, etc.) will do the job, but keep in mind that different brands use different combinations of bacteria, and this accounts for variability in flavors ranging from buttery to cheesy to tangy to mild; textures can be firm, thin, gelatinous, ropy, or custardy. These qualities will transfer to your finished yogurt.
Then there’s the milk. Any type (whole, low-fat, or skim) will work, but the more fat your milk contains, the richer your yogurt will be and the more structure it will have.
And yet, the starter and milk are only the beginning. Here are more ways to create a truly artisanal yogurt to suit your personal tastes.
Tweak the Consistency
Control Sourness and Thickness
Adjust the incubation time to produce the effect you desire: The longer yogurt ferments, the more lactic acid is produced, and the more sour and thick it becomes. Chilling stops fermentation and allows the gel to set fully (it will loosen when stirred or served).