An unopened container should last for 1-3 months at 40°F or less in the refrigerator, but some companies guarantee their product for up to 6 months. In general, all foods last only as long as the quickest expiring ingredient that they are mixed with. With proper storage, buttermilk may last up to 1 – 2 weeks after the date. Check for discolouration and sour smell or taste (eating a small amount won’t hurt your health). Rosa graduated with a master degree in Food Safety from Wageningen University and Research, The Netherlands. Be sure the butter is very cold. Buttermilk is a dairy product made by fermenting milk with lactic acid bacteria. If you are not going to use the butter within a couple of weeks of purchasing, it should be stored in the freezer. Add the expired buttermilk to cooked recipes that call for buttermilk in the ingredient list. Some baked goods that typically use buttermilk include pancakes, pies and biscuits. Contrary to popular belief, food that has passed by the date might still be safe to consume.What makes you sick is spoiled food. Thaw and use for baking. However, the texture and color may change slightly. This habit can transfer bacteria from your mouth and will spoil the buttermilk in no time. Some benefits of proper food storage include eating healthier, cutting food costs and helping the environment by avoiding waste. As a product of the fermentation process, buttermilk is naturally sour, however, if the smell or taste is extremely sour, it is a telltale that buttermilk is bad and should not be consumed. Always keep the remaining product in the fridge until the next use. But to summarize, buttermilk can be enjoyed as a refreshing drink, as well as used for baking and cooking. Buttermilk will go bad quickly if not stored properly. So, how long does butter last? Just be cautious of the water bottles it may be siting in. But remember, many food products carry a "best by date" which is simply the last date the manufacturer will guaranty the quality, not the safety, of their product. In addition to its use as a cooking tool and being used as a tasty compliment to items such as bread or potatoes, butter does have some nutritional benefits which include a high dose of vitamin A. Give it a good stir to get the consistency back. Since your cookies will be baked, I would consider this a very low food safety risk. If you use ice cube trays, once buttermilk is frozen, transfer the cubes into a freezer bag. In other words: Melted butter will result in a flat, super chewy cookie, while softened butter makes for a fluffier, softer cookie. Please eat responsibly! Just make sure you defrost the butter overnight in the refrigerator before using it. Butter. In addition, we scoured the web for informative articles and reports related to food safety, food storage and the shelf life of Butter. Although salted varieties may last longer, we do recommend that you follow the same storage methods discussed above. Most butter has an expiry date on it. In addition to its use as a cooking tool and being used as a tasty compliment to items such as bread or potatoes , butter does have some nutritional benefits which include a high dose of vitamin A. All rights reserved. Powdered butter is a light powder that can be used to replace butter in a 1-1 substitution in most baking recipes. In determining how long Butter lasts, our content incorporates research from multiple resources, including the United States Department of Agriculture and the United States Food & Drug Administration. You probably didn’t finish the bottle and kept the remaining in the back of the fridge.