Keep yogurt in the refrigerator. Cover tightly to keep it from drying out, spoiling, or taking on the flavors of other foods in the refrigerator.
If stored well (refrigerated and covered), yogurt is safe to eat after the ‘use by’ date but the flavor may be more tart and the liquid may have separated out. (It will need to be stirred.) Discard the entire container if any mold has appeared.
Freezing yogurt is safe but the texture will not be the same after thawing