The best natural Greek yogurt is one that is thick, creamy and free of additives and preservatives. Authentic natural Greek yogurt does not contain any thickeners such as gelatin or cornstarch but is naturally thick due to the process of straining off the liquid whey. This concentrates and increases the protein in a carton of yogurt but slightly reduces the calcium. The best natural Greek yogurt may be more expensive than other types as it takes about three times as much milk to make.
Greek yogurt is rich in nutrients and friendly bacteria. Both regular and natural Greek yogurt are made by adding the live bacteria cultures, Streptococcus thermophilus and Lactobacillus bulgaricus, to milk in order to ferment it. The liquid whey is then removed from the Greek yogurt to thicken the consistency. A comparison of a carton of regular yogurt with a carton of natural Greek yogurt shows that there are more calories and significantly more protein in Greek yogurt but less calcium compared to regular yogurt.
Yogurts with a long list of ingredients are ones that have had fillers such as thickeners, sweeteners and artificial flavors and colors added to them. These ingredients reduce the goodness and increase the calorie count, so the best yogurt to buy is the one with the least ingredients. In the case of natural Greek yogurt, these should be milk cream, yogurt culture and cow's or sheep's milk. On the carton, there should be a label that indicates the yogurt culture is live and active.
Probiotics or live cultures are present in all natural Greek yogurts. They promote cellular immunity, better gut health and increase good cholesterol. While all yogurts are made using bacteria cultures, not all of them have the same amount. The "live culture" label on a carton means that the yogurt contains a significant amount of culture per gram of product. Some companies add extra probiotics and cultures in an effort to promote the yogurt as even more beneficial for immunity and digestive health. Some yogurts are heat-treated after fermentation and this will have killed off most of the beneficial bacteria.
A natural yogurt with no added ingredients which has not been heat treated and carries the "live culture" label will always be the healthiest option. Other than that, it is simply a case of taste. Some people who are used to sweetened products may find the taste of natural Greek yogurt a bit sharp or tart but the creaminess and texture are adequate compensation for most.