This just came into the Guild mailbox:
“I make yogurt in a licensed creamery and we’ve been seeing huge (infinite?) shelf lives for our yogurt, upwards of four weeks in the fridge, with a tangier taste but nothing evil going on. We’re currently putting a 2-week expiration date on our yogurt that we sell in stores, but we are tempted to make this date longer or to change wording so that retailers feel comfortable letting stock hang around. I’m curious to see if anyone in the cheese guild has had any experience with this issue, as there apparently aren’t any state guidelines to which we can refer, and the MMDC doesn’t bring up shelf life, either.
Thanks very much for any help you can offer.”
I make the White Gold version of local yogurt sold in Belfast, and I’m pretty sure the dairy reg.’s mention 3 weeks (though it may be vague) as the shelf-life of yogurt in the stores. That’s what I’ve used for many years and the inspectors have seconded that decision. However, as you’ve point out, if it is *not opened* yogurt can last much longer. I have a farmer’s market customer who “discovered” a jar of my yogurt after six months in their summer home fridge (I take it the fridge was on the whole time). She was curious, opened the jar, and ate the yogurt and said it tasted fine. As it’s an acidic cultured product that should be a monoculture of yogurt cultures after fermentation if not contaminated by other bacteria before hand it could last for a long time at refrigerated temps. But that last bit is the key — a contamination may not surface after three weeks, but will surface the longer it sits. There are bacteria that grow well at refrigerator temps (such as those that spoil milk in the fridge), they just grow slowly. So even though some samples have gone much longer than two or three weeks, that doesn’t mean that EVERY sample will. Where as if the yogurt is made properly, and is kept properly refrigerated, EVERY jar should easily last three weeks on the store shelf, and another fourth week in the customer’s refrigerator as they consume it in the worst case.
Therefore, as a producer, I would not want to change the three week sell-by date, even if the store doesn’t mind and the inspector doesn’t notice. Plus, as a producer, I’m not sure I’d want “old yogurt” to represent my brand, especially if it’s always next to “new yogurt” on the shelf. If you don’t have enough markets to sell out your yogurt batches within three weeks, you’re better off making cheese, especially aged cheese, with that extra milk because it will definitely keep longer, plus appeal to a different market. If it’s only a few bottles from every batch, feed it to livestock, or make lots of yogurt cheese for your in-house consumption…
I hope that helps,