Do Greek yogurts come from Greece?
By: Howard Bonnemann, SDSU Extension, Lecturer & Dairy Plant Manager
According to the Code of Federal Regulations (CFR), Title 21 subsection 131.200; Yogurt is defined as a cultured, fermented dairy product that contains at least two specific species of microorganisms, Streptococcus thermophilus and Lactobacillus delbrueckii ssp. bulgaricus.
Yogurt may be manufactured in four categories based on levels of milk fat: a full-fat product containing at least 3.25% milk fat, a reduced fat product with 2% milk fat, a low fat product with 1% milk fat or a nonfat product containing less than 0.5% milk fat. The cultured, fermented dairy product may contain added vitamins, flavorings and sweeteners. The initial dairy blend must be pasteurized prior to the addition of the microbial cultures to ensure safety and successful fermentation. Nowhere within the definition is there an allowance for addition of fat or protein from other than mammalian sources.
Typically, a plain, unsweetened, yogurt manufactured to the standards set forth in the CFR will contain approximately 3.1% protein in the initial milk, without fortification, which results in about 6 to 8 grams of protein per 6 ounce serving depending upon the initial level of milk fat. The amount of protein per serving will increase in lowered fat yogurts as the initial level of protein in the milk will increase slightly due to a concentration of the milk-solids-not-fat when separating out the milk fat as cream. The total solids level in a plain, unsweetened yogurt will be between 9 and about 12% depending upon the amount of milk fat included. Therefore, lower fat yogurts will contain more grams of protein per serving than their higher fat counterparts.
A Greek-style yogurt does not have to be manufactured in the country of Greece. The term Greek when attached to a yogurt implies that the original fermented product has been strained to remove a portion of the moisture (as acid whey) which results in a more concentrated product, higher in total solids with an increased level of protein in each serving. There is no standardized method for this straining or concentrating step in the overall process which lends itself to a degree of variability in the levels of protein available per serving dependent on the manufacturer. There is not a standard of identity for a Greek-style yogurt outlined in the CFR beyond the basic requirement of the two specific microbial strains that must be utilized for the initial fermentation. Many companies target an increase in grams of protein per serving approximately double that contained in a plain yogurt.
The process of straining the yogurt removes not only water but also some of the residual lactose remaining after the fermentation along with a small portion of serum proteins that did not participate in the formation of the gel-like structure. Some of the milk minerals, which are primarily water soluble, also are removed during the straining process. Therefore a careful reading of the nutritional label is essential to understanding what is actually present in a Greek-style yogurt dependent upon company and location of manufacture. A Greek-style yogurt appears to taste more acidic because of changes in the buffering capacity of the overall system related to the increase in protein content.