Homemade Yogurt Part 1 (The Science)

*(Note that “frozen yogurt” deserves its own separate category and should not be associated with the health benefits listed above–the only requirements the FDA mandates is that it contain live bacterial cultures at the time of processing–there is not a requirement on the number although many won’t survive extended periods of time in the freezer anyway, and there is no limit to the unhealthy ingredients they add–next time you’re in the grocery store check out the ingredients list and compare it to ice cream. You’ll notice very little difference.)

So what is yogurt? It’s simply fermented milk which varies in taste, texture, and appearance depending on the specific bacterial culture used in fermenting. It is naturally sour. While today’s definition has extended “yogurt” to including non-dairy milks such as almond, soy, rice etc, traditionally yogurt is a cultured animal milk (cow or goat). Yogurt is healthier and more digestible than regular milk because:

• The beneficial bacteria break down much of the lactose–a milk sugar difficult for many people to digest
• The protein casein, also difficult to digest, is partially broken down
• The cultured product is fully of beneficial (probiotic) bacteria to help repopulate the gut (which is full of a combination of both beneficial and harmful bacteria at any given time) with “good guys”
• Certain vitamins are increased
• Additional benefits are extended shelf life (as the “putrefying” bacteria are destroyed) and improved texture and flavor

What does yogurt taste like? Real plain yogurt is generally sour, tangy, and creamy–all of which can be manipulated by the type of milk used, the bacterial strain added, the amount of time left to ferment, and straining or additional ingredients.

• Milk–Yogurt can be made with any animal milk (cow, goat, sheep, cats–a credible source cited you can milk anything with nipples).  Cows milk will generally yield a thicker milk than goat or sheep, though goat milk is often more easily tolerated in those with milk sensitivities. Additionally, yogurt can be made with any level of fat content–whole, 2%, 1% or skim. Whole milk will always yield a better overall taste (richer) and texture (thicker) than lower fat versions. The less processes a milk has undergone, the better the enzymes and the richer the nutrients. Raw milk will still contain live enzymes, but will yield a thinner consistency than pasteurized. Commercially pasteurized and homogenized milk (all that is sold in the store) has been heated to a temperature high enough to kill all the live enzymes (160 F) in the milk; however when cultured and fermented with live bacteria will still yield a nutritionally beneficial product. However, ultrapasturzied milk has been heated to such a high temp (280 F) that much in the milk has been destroyed. Take note of any milk that has a surprisingly extended shelf life–chances are it has been ultrapasturized and shouldn’t be used for making yogurt. I’ve also found the fresher the milk, the better the yogurt–I thought it might be the case that since it was souring anyway it would be fine to wait a week or so, but so–I’d recommend wait until the day you’re going to make yogurt to use get your milk.