On One Hand: Sealed ContainersThe Natural Center for Food Preservation warns that any canned food item, bought or homemade, is at risk for Clostridium botulinum bacteria, which causes food poisoning. Apple butter has enough acidity from the apples in it to prevent the growth of Clostridium botulinum and requires no refrigeration for sealed containers.
On the Other: Unsealed ContainersOnce the seal is broken on a jar of apple butter, it should be refrigerated to prevent food poisoning and spoilage. The Natural Center for Food Preservation recommends not leaving apple butter out and unrefrigerated for more than two consecutive hours to reduce the risk of food poisoning and contamination. Refrigeration slows the growth of any harmful bacteria and increases the safety of eating apple butter.
Bottom LineAlways refrigerate apple butter that has a broken seal or has been opened. If you are unsure if the apple butter is safe to eat, discard it. It will not hurt apple butter to refrigerate sealed and unopened containers.
Source:Natural Center for Food Preservation: Ensuring Safe Canned Goods
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