Traditionally, buttermilk (chaas) is the residual liquid obtained after churning cream to make butter. Despite its name, this delightful dairy product is low in fat and serves as a valuable source of protein, offering approximately 8 grams per cup (250 mL). Characterized by its distinct tangy flavor and thicker consistency compared to regular milk, buttermilk is rich in lactic acid, making it an excellent ingredient for baking. It is extensively used in the preparation of various baked goods, including breads, pancakes, and other quick breads. In addition to its baking applications, buttermilk is enjoyed as a refreshing beverage, transformed into cheese, or blended into sauces and dips to enhance flavor and achieve a creamier texture. Nonetheless, due to its unique tanginess, many individuals find it challenging to determine when buttermilk has spoiled and is no longer safe for consumption.

This article provides comprehensive insights into buttermilk, including its shelf life and storage tips.

Understanding Cultured and Traditional Buttermilk

The buttermilk you find at your local supermarket, often referred to as cultured buttermilk, typically differs significantly from the traditional buttermilk that was originally crafted on farms. Cultured buttermilk is produced using a method similar to that of yogurt. It involves adding bacterial cultures (Lactococcus lactis ssp. lactis), salt, and citric acid to skim milk, which then ferments for approximately 14 to 16 hours. This fermentation process converts the sugars present in milk into lactic acid, imparting a distinctively tangy flavor. On the other hand, traditional buttermilk is a byproduct of the butter-making process itself. It is the liquid that remains after the fat has been separated from cultured butter. When compared to its cultured counterpart, traditional buttermilk tends to be less tangy and sour, offering a creamier texture.

In the United States, buttermilk must undergo pasteurization, which involves heating it to 161°F (71.7°C) for a minimum of 15 seconds. This essential process not only extends the shelf life of buttermilk but also eliminates harmful bacteria, ensuring safety for consumers. While most of the buttermilk available in grocery stores is cultured, many chefs and culinary professionals prefer traditional buttermilk due to its superior flavor and texture. This preference highlights the diversity within the buttermilk family and showcases the unique qualities of both types.

In summary, cultured buttermilk is derived from skim milk with the addition of bacterial cultures, salt, and citric acid, while traditional buttermilk is simply the liquid left over from the butter-making process.

Shelf Life of Buttermilk

Understanding the shelf life of buttermilk is crucial to ensure that you are enjoying the best quality and safest product available. Buttermilk is rich in lactic acid and a compound called diacetyl, which contribute to its characteristic tangy and buttery taste. With time, it tends to sour further, and the bacteria responsible for the diacetyl production diminish, leading to a decline in flavor. If you find yourself with buttermilk that you cannot use before it reaches its expiration, freezing might be a viable option. However, keep in mind that freezing can change the texture and taste of buttermilk, making it more suitable for baking than for direct consumption.

It is advisable to avoid purchasing unpasteurized buttermilk, as this can heighten your risk of foodborne illnesses. Making sure to consume buttermilk within its suggested time frame guarantees not only great taste but also safety. Refer to the chart below for guidance:

If you decide to freeze your buttermilk, you can do so in its original container, provided there is enough room for expansion. This prevents the container from bursting in the freezer. Alternatively, you may transfer the buttermilk into a sealed, airtight container before freezing. However, be aware that buttermilk can spoil before its expiration date due to improper handling, temperature fluctuations, or other factors. Thus, it is important to look for indicators that your buttermilk may have gone bad, which will be discussed later. Buttermilk can remain fresh for up to 14 days in the refrigerator after being opened, and it may last even longer if left unopened. Nevertheless, it is always recommended to consume it as soon as possible for the best experience.

How to Determine if Buttermilk Has Spoiled

Aside from checking its expiration date, there are several other indicators that can signal your buttermilk has spoiled. These include:

• unusual thickening or the presence of chunks
• visible mold growth
• a strong, unpleasant odor
• any discoloration

In general, if your buttermilk appears different from how it looked when you bought it, this is a significant warning sign. While these are common indicators, if you suspect that your buttermilk has spoiled, it is advisable to discard it to avoid any potential health risks. If you notice any changes in smell, texture, color, or the appearance of mold, it's best to dispose of the buttermilk immediately.

Extending the Shelf Life of Buttermilk

To maximize the freshness and longevity of your buttermilk, it's essential to maintain proper hygiene during its handling. Always ensure your hands are thoroughly washed, avoid touching the rim of the bottle directly, and refrain from drinking straight from it. As with most dairy products, buttermilk must be kept refrigerated at a temperature below 40°F (4.4°C) to inhibit the rapid growth of harmful bacteria. It's advisable not to store it in the fridge door, where temperature variations are more common.

Leaving buttermilk out at room temperature can significantly shorten its shelf life. Always return it to the fridge immediately after use to keep it out of the danger zone, which is between 40–140°F (4.4–60°C) where bacteria proliferate swiftly. For those mindful of food waste, consider buying buttermilk in the smallest available size and ensure you consume it within its suggested shelf life.

In summary, to prevent buttermilk from spoiling prematurely, prioritize cleanliness and store it in the coldest section of your refrigerator, consistently keeping it below 40°F (4.4°C).

The Bottom Line

Buttermilk, a delightful and tangy beverage, is not only enjoyable on its own but also serves as an excellent ingredient in various cooking and baking endeavors. Commonly found in stores, cultured buttermilk is produced through a distinct fermentation process, differing from the traditional method. Regardless of the type, both varieties have limited shelf lives and should be kept refrigerated at temperatures below 40°F (4.4°C). Once opened, buttermilk can remain fresh in the refrigerator for approximately 14 days, while unopened containers may last slightly longer beyond their expiration date. For extended storage, buttermilk can be frozen, whether opened or unopened, in an airtight container for up to 3 months. It's crucial to inspect buttermilk for any changes in odor or appearance; if you observe any abnormalities, it is advisable to discard it to prevent any health risks.