Buttermilk: A Complete Guide to Buying, Storing, and Eating

Category: Dairy & Eggs

buttermilk

🤔 What Is Buttermilk?

Modern buttermilk is a fermented dairy product made by adding a culture of lactic acid bacteria to low-fat milk, which thickens it and gives it a distinctively tangy flavor. It is prized in baking for its ability to create exceptionally tender cakes and scones, and is also used as a marinade to tenderize chicken.

Quick Reference Card

Condition Ideal Storage Duration
Unopened Buttermilk Refrigerator: 0-4°C (32-39°F) Until ‘Best By’ date
Opened Buttermilk Refrigerator: 0-4°C (32-39°F) 5-7 days
Frozen Freezer: -18°C (0°F or below) Up to 3 months
Signs It’s Spoiled: A very sour or foul smell, significant thickening or large clumps, or any visible mold.

The Triple-S Method

Master the three essential steps for food success:

🛒 SHOP SMART: Selection Guide

⚡ Shopping Fast Facts:

  • Always check the “Best By” or “Use By” date.
  • Ensure the carton or bottle is sealed and has no leaks.
  • Choose full-fat or low-fat based on your recipe’s requirements.

Appearance

Buttermilk should be a uniform off-white color and thicker than regular milk, but still pourable. Small flecks are normal, as they are bits of butterfat.

Smell

It should have a clean, tangy, and pleasantly sour smell, similar to plain yogurt. Any foul or overly sour odors indicate spoilage.

Texture

Cultured buttermilk is smooth and slightly thick. Some separation is normal; just shake the container well before use.

Common Varieties / Types

The primary types are based on the production method.

  • Cultured Buttermilk: The most common type available in stores. It is made by adding live cultures to milk, similar to how yogurt is made.
  • Traditional Buttermilk: The original form, which is the slightly sour liquid left over after churning butter from cream. It is much thinner and is rarely sold commercially.

📅 Seasonal Buying Guide

Buttermilk is a dairy product that is available with consistent quality year-round.

❄ STORE FRESH: Storage Guide

⚡ Storage Fast Facts:

  • Primary Method: Refrigerator, tightly sealed.
  • Unopened: Until the “Best By” date.
  • Opened: For 5-7 days.

Storage Method Details

Refrigerator: Buttermilk must always be stored in the refrigerator with the cap tightly sealed to prevent it from absorbing other odors. An unopened container will last until the date on the carton.

Opened Buttermilk: According to the USDA, once opened, buttermilk is susceptible to spoilage bacteria. It should be consumed within 5-7 days for the best quality and safety. Always check for a foul smell or mold before using.

🔬 Why These Timeframes Work:

While the live cultures and acidity in buttermilk provide some natural preservation, it is still a fresh dairy product with high moisture content. The cold temperature of the refrigerator is essential to slow the growth of unwanted spoilage bacteria and mold after the container’s seal is broken.

⚠ STAY SAFE: Food Safety Tips

⚡ Safety Fast Facts:

  • Max Time at Room Temp: 2 Hours

Understanding Food Safety Rules

Never leave buttermilk out of the refrigerator for more than two hours. According to the FDA, this is the maximum time a perishable dairy product can be in the temperature danger zone (4°C-60°C / 40°F-140°F) before harmful bacteria can multiply to unsafe levels.

Reheating Methods

Buttermilk is not typically reheated on its own as it will curdle. It is used as an ingredient in dishes that are then cooked or baked.

Date Labels Explained

The “Best By” or “Use By” date on a carton of buttermilk is an important quality and safety guide. Due to its nature, it is not recommended to consume buttermilk far beyond this date, even if unopened.

Allergen Information

⚠ Allergen Alert:

  • Contains: Milk.

Allergen Handling & Prevention

Buttermilk is a dairy product and will cause a reaction in individuals with a milk allergy. It contains lactose and may cause issues for those with lactose intolerance.

⚠ Special Safety Considerations

Do not consume buttermilk if it has a foul odor, has thickened considerably, or shows any sign of mold. While it is naturally sour, a spoiled product will smell distinctly “off” and unpleasant.

Pasteurization Info

Virtually all commercially available buttermilk is made from pasteurized milk. As the FDA explains, this process kills harmful bacteria like Listeria, making the product safe for consumption.

🧊 Freezing & Thawing Guide

Freezing Effects & Preparation

Buttermilk can be frozen, but the process will cause it to separate and become grainy upon thawing. It is no longer suitable for drinking but remains perfectly effective for use in baked goods.

To freeze, shake the buttermilk well and pour it into ice cube trays for convenient, pre-measured portions. Once solid, transfer the cubes to a freezer bag.

Recommended Thawing Methods

Thaw buttermilk cubes in the refrigerator overnight. The thawed liquid will be separated; whisk it vigorously or blend it briefly to re-emulsify it as much as possible before adding it to your batter.

Not Recommended

Do not thaw buttermilk at room temperature due to food safety risks.

📊 Nutritional Information

Average values per 100g (approx. 3.5 oz) portion

⚡ Nutrition Highlights:

  • High in: Calcium, Vitamin B12
  • Good source of: Protein, Riboflavin, Probiotics

Buttermilk (Low-Fat)

  • Calories: 40 kcal
  • Protein: 3.3g
  • Fat: 0.9g
  • Carbohydrates: 4.8g
  • Fiber: 0g

Key Nutrients & Their Benefits

  • Probiotics: As a fermented food, cultured buttermilk contains live beneficial bacteria that can help support a healthy gut microbiome.
  • Calcium: An essential mineral for building and maintaining strong bones and teeth.
  • Protein: Provides high-quality protein that is important for muscle maintenance and overall body function.

Nutritional data is an estimate. Consult with a nutritionist for personalized advice.

🌎 Sustainability & Sourcing

The environmental impact of buttermilk is similar to that of other dairy products, which is tied to the resource intensity of dairy farming. Traditional buttermilk is a sustainable byproduct of butter making.

Choosing buttermilk from local or organic dairies that prioritize sustainable farming practices is a more environmentally conscious option.

🔄 Substitutions & Alternatives

The most common and effective substitute is to make your own “sour milk.” For every 250ml (1 cup) of buttermilk needed, add one tablespoon of lemon juice or white vinegar to regular milk and let it sit for 5-10 minutes until it curdles slightly.

Plain yogurt or kefir, thinned with a little milk, can also be used as a substitute in many recipes.

💡 Pro Tips

♻ Waste Reduction

Because recipes often call for small amounts of buttermilk, freezing the leftovers is the best way to prevent waste. An ice cube tray typically holds about 2 tablespoons per cube, making it easy to thaw exactly what you need for your next batch of pancakes or scones.

❓ FAQ

Q: Why is buttermilk so good for baking?
A: The acidity of buttermilk reacts with alkaline leavening agents like baking soda, creating carbon dioxide bubbles that make baked goods exceptionally light and tender. It also helps to break down gluten, resulting in a softer crumb.
Q: Is buttermilk high in fat?
A: Despite its name, modern cultured buttermilk is typically low in fat. It is made from low-fat or skim milk, not butter.
Q: My buttermilk looks clumpy. Has it gone bad?
A: Some separation and small clumps are normal for buttermilk. As long as it smells fresh and tangy and is within its use-by date, simply shake the carton vigorously to recombine it.
Q: Can I make my own buttermilk?
A: Yes, the easiest way is to add one tablespoon of an acid like lemon juice or white vinegar to one cup of regular milk. Let it stand for about 10 minutes until it thickens slightly.
Q: What is the difference between buttermilk and kefir?
A: Both are fermented milk drinks, but they use different cultures. Kefir is fermented with both bacteria and yeast (“kefir grains”) and is typically thicker and has a more pronounced effervescence and tangy flavor.
Q: Can I drink buttermilk straight?
A: Yes, many people enjoy drinking cold buttermilk. It has a tangy, refreshing taste similar to a drinkable yogurt.
Q: Is buttermilk good for marinating chicken?
A: Yes, it is excellent. The mild acidity and enzymes in buttermilk help to tenderize the chicken without making it tough, resulting in a very moist and flavorful final product.
Q: Can I use buttermilk past the expiration date?
A: It is not recommended. While it is a cultured product, it can still grow harmful molds or bacteria once it has passed its prime. Discard it if it smells overly sour or has any signs of spoilage.
Q: Is buttermilk the same as the liquid from making butter?
A: Traditionally, yes. However, the buttermilk you buy in the store today is “cultured buttermilk,” which is milk that has been intentionally fermented with a bacterial culture.
Q: What is powdered buttermilk?
A: Powdered buttermilk is a shelf-stable dehydrated version. It can be reconstituted with water or added directly to the dry ingredients in a baking recipe, making it a very convenient pantry staple.

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