April 3, 2012
There have been a lot of questions about yogurt (yoghurt) lately, mostly about eating it even after the eat by date, questions about how long yogurt (yoghurt) really and truly lasts. Yes, most yogurts can be eaten for slightly longer than the eat by date chart. But, yes there is a but, … the product may not be the same after the eat by date even though it may look the same so it is important to realize why you are eating the yogurt and what is really going on with live yogurt cultures.
It’s the active bacteria cultures in yogurt (yoghurt) that boost digestive health. Micro-organisms, or bacteria cultures, are introduced into milk in order to thicken it and turn it into yogurt (yoghurt). The resulting product then has yogurt cultures. This happens because the bacteria eat the lactose in the milk, converting the sugars into lactic acid which provides the tangy taste in yogurt (yoghurt). These yogurt cultures are considered “good bacteria” and when they reach our digestive tracts they overtake the “bad bacteria” in our systems and restore a normal balance, both boosting our digestive health and supporting our immune system.
Since 70% of the our immune system is located in the digestive tract, it’s the best place to receive a boost. Bad bacteria can multiply with surgery, antibiotics, bad diet, traveling, stress, certain medications, alcohol, smoking and aging. A cup of yogurt a day (containing yogurt cultures) is supposed to replenish the microorganisms that live naturally in the digestive tract and may have been killed off by one of the above mentioned factors.
So, the problem is that once the bacteria in your yogurt have eaten all of the lactose within the container, then they die. That means that older yogurt may not contain living bacteria yogurt cultures anymore, thus eliminating it’s health benefit. This is also true for yogurt that has not been refrigerated properly, since bacteria grows much more rapidly in a warm environment the yogurt cultures will eat more rapidly and thus the yogurt will spoil sooner. I’ve eaten yogurt for 2-3 months beyond its use by date, and also past it’s eat by date, but I eat it mostly for the food value not the health value of the yogurt cultures. Be sure to check the EatByDate yogurt (yoghurt) page on how to tell if yogurt is going bad or has totally gone bad before eating. If you are eating yogurt for the health benefits, you want to make sure that the probiotics are alive and well!
Remember, yogurt cultures must be alive to do their job.