How to Make Whey for Fermentation: A Simple Guide

Did you know that whey is a nutrient-rich byproduct of cheesemaking that contains beneficial bacteria, making it an excellent natural starter for fermentation? Discover how to make whey for fermentation at home with these simple, effective methods using common dairy products.

Quick Summary

Homemade whey is a versatile starter for lacto-fermenting vegetables, fruits, or dairy. Separated from yogurt or clabbered raw milk, this clear, liquid gold provides beneficial bacteria and nutrients to extend the shelf life of many fermented foods.

Key Points

• Method Selection: Choose between the simple yogurt straining method or the traditional raw milk clabbering to produce acid whey for fermentation.

• Essential Equipment: You only need a few simple tools, including a strainer, bowl, and fine cheesecloth or a clean flour sack towel.

• Optimal Results: For the best, most potent whey, strain yogurt or clabbered milk in the refrigerator for 8-24 hours until the liquid is clear and pale yellow.

• Versatile Uses: Homemade acid whey can be used as a starter culture for lacto-fermenting vegetables, fermenting dairy, or added to baked goods.

• Storage: Clear, tangy whey stores well in a sealed jar in the refrigerator for several months, while freezing can extend its life, though it may weaken the active cultures.

• Best Practices: Ensure cleanliness, use a salt brine alongside whey for vegetables, and discard any whey that develops a foul odor or mold.

What is Whey for Fermentation?

Whey is the nutrient-dense liquid that separates from milk solids (curds) during the cheesemaking process. For fermentation purposes, particularly lacto-fermentation, a specific type of whey is needed: acid whey. This is the byproduct from dairy that has been soured with a live culture, like yogurt, kefir, or clabbered raw milk. The live lactic acid bacteria present in this whey are what you need to kickstart your fermentation projects. They consume the lactose (milk sugar) and produce lactic acid, which both preserves the food and creates that signature tangy flavor.

It's important to distinguish acid whey from sweet whey. Sweet whey is produced using a rennet coagulant, typically for harder cheeses, and does not contain the necessary active cultures for lacto-fermentation. It has a milder taste and is generally used for baking or nutritional supplements. For home fermentation, acid whey is the liquid gold you are after.

Method 1: Making Whey from Yogurt

This is the simplest and most accessible method for home cooks, as it requires only plain yogurt with live cultures. Straining yogurt concentrates the milk solids into a thicker consistency (like Greek yogurt) and leaves you with the liquid whey.

Equipment Needed

• 1 large glass bowl or measuring cup
• 1 colander or large strainer
• 1 piece of fine cheesecloth, a clean thin flour sack towel, or nut milk bag
• 1 container for storing the finished whey

Step-by-Step Process

1. Prepare the Setup: Set the colander or strainer over your large bowl, leaving enough room for the liquid to collect without the strainer touching it. Line the strainer with a multi-layered cheesecloth, or a clean, tightly woven towel.
2. Add the Yogurt: Gently pour or spoon the plain, live-cultured yogurt into the cloth-lined strainer.
3. Strain: Cover the setup with a lid or plastic wrap to prevent anything from falling into it and place it in the refrigerator. Allowing it to strain in the fridge is ideal for a clearer whey.
4. Wait: The straining process typically takes 8 to 24 hours. The longer you let it strain, the thicker your resulting yogurt cheese will be, and the more whey you will collect. For a Greek-style yogurt, a few hours may suffice; for a thick, cream-cheese-like consistency, let it go overnight or longer.
5. Collect and Store: Once you have your desired amount of clear, pale yellow whey, pour it from the bowl into a clean glass jar with a tight-fitting lid. Refrigerate the whey, where it can last for several months. The leftover yogurt cheese can be stored separately.

Method 2: Making Whey from Raw Milk

This traditional method involves allowing raw, unpasteurized milk to 'clabber' naturally at room temperature. The natural bacteria in the milk will cause it to separate into curds and whey on its own.

Equipment Needed

• 1 quart of raw, grass-fed milk
• 1 large glass bowl
• 1 clean cloth (thin dishtowel or fine cheesecloth)
• 1 rubber band
• 1 large wooden spoon for hanging (optional)
• 1 container for storing the finished whey

Step-by-Step Process

1. Clabber the Milk: Pour the raw milk into a clean glass jar or bowl and cover it loosely to protect it from dust. Let it sit on the counter at room temperature for 1 to 3 days. The time depends on the ambient temperature; a warmer room will speed up the process. The milk is ready when it has visibly separated into solid white curds and a clear, yellow liquid whey.
2. Strain the Curds and Whey: Set up your straining station as in the yogurt method, with the cloth-lined strainer over a large bowl.
3. Separate: Gently pour the clabbered milk into the cloth. Gather the ends of the cloth and secure it with a rubber band.
4. Drip: For maximum whey extraction, tie the bundle to a cabinet knob with a rubber band or string and let it hang over the bowl. The whey will drip for an hour or two. Alternatively, just let it sit in the strainer overnight in the refrigerator.
5. Store: Pour the collected whey into a glass jar and refrigerate. The resulting curds can be used to make a fresh cheese or spread.

Acid Whey vs. Sweet Whey for Fermentation: A Comparison

To highlight the difference between the two types of whey and their uses, here is a helpful comparison table. For most home fermentation projects, acid whey is the preferred choice due to its living bacterial cultures and suitable pH.

Feature	Acid Whey	Sweet Whey
Source	Strained yogurt, kefir, clabbered milk	Byproduct of rennet-based cheesemaking
pH Level	Below 5.0, acidic	6.0 to 7.0, neutral to slightly acidic
Taste	Tangy and sour	Milder and sweeter
Active Cultures	Contains a high concentration of live lactic acid bacteria	Does not contain a high concentration of live bacteria after processing
Best for Fermentation	Yes, excellent starter for lacto-fermenting vegetables and dairy	No, lacks the necessary bacteria for lacto-fermentation
Other Uses	Substitute for buttermilk, acidulant in cooking	Baking, smoothies, supplements

Tips for Successful Whey Fermentation

• Cleanliness is Key: Always use clean and sanitized equipment to prevent the growth of unwanted bacteria that could ruin your ferment. Wash all bowls, strainers, and jars thoroughly.
• Use Clear Whey: The clearest, palest yellow whey is the most potent and best for fermentation. If your whey is cloudy or milky, it contains milk solids and is less ideal as a starter.
• Use a Salt Brine: When fermenting vegetables, using whey as a starter still requires a salt brine. The salt helps control the fermentation process and keeps vegetables crunchy.
• Start with Less: For liquid ferments, you can begin with a small amount, such as 1-2 tablespoons of whey per quart of liquid, and adjust as needed for taste.
• Know When to Discard: If your whey develops a foul odor, fuzzy mold, or other signs of spoilage, discard it immediately. Good whey should smell pleasantly tangy.

Using Your Homemade Whey

Once you've collected your liquid gold, the world of fermentation opens up. You can use this potent starter to create a wide variety of delicious and gut-healthy foods.

• Lacto-Ferment Vegetables: Add a tablespoon or two of whey to your brine when making sauerkraut, kimchi, or pickled vegetables. The whey can help kickstart fermentation and add flavor.
• Make Dairy Ferments: Use a splash of whey to inoculate another batch of homemade yogurt, kefir, or buttermilk. This is an excellent way to keep your culture alive without using a portion of the previous batch.
• Create Fermented Drinks: Use whey to make naturally carbonated, probiotic-rich beverages like ginger ale or fermented lemonade. Combine whey with juice and water, and let it sit for a few days until fizzy.
• Baking: Replace water or milk with whey in bread recipes for a softer, more flavorful dough with a slight sourdough tang. It can also be used in pancakes, waffles, and cakes.
• Add to Smoothies: Boost the protein and probiotic content of your morning smoothie by adding a couple of tablespoons of whey.

Conclusion

Making your own whey for fermentation is a straightforward process that allows you to control the quality of your starter culture while eliminating food waste. Whether you choose the quick yogurt straining method or the traditional raw milk clabbering, the resulting clear, probiotic-rich liquid is a valuable tool for creating a wide array of fermented foods. By following a few simple steps, you can harness the power of beneficial bacteria to enhance the flavor, nutrition, and longevity of your homemade ferments. For more information on fermentation techniques, consult resources like Cultures For Health for guidance on salt-based and starter-based ferments.

Frequently Asked Questions

1. Can I use whey from store-bought yogurt? Yes, as long as it's plain, unflavored yogurt and the label clearly states that it contains live and active cultures. Flavored or sweetened yogurts contain sugars that can interfere with fermentation.

2. Is it safe to strain yogurt at room temperature? Yes, straining yogurt for a few hours at room temperature is generally safe, especially in a cooler environment. However, for a longer strain (overnight or longer), it is best to place the setup in the refrigerator to prevent over-fermentation and reduce the risk of spoilage.

3. How do I know if my clabbered raw milk is ready to be strained? It is ready when the curds and whey have completely separated into two distinct layers. The whey should look pale yellow and translucent, and the curds should be a solid, cottage cheese-like mass.

4. How long does homemade whey last in the refrigerator? Clear, acid whey can be stored in a sealed glass jar in the refrigerator for several months. It should maintain a pleasant, tangy smell. If it smells off, or you see mold, discard it.

5. Can I freeze whey for future use? Yes, you can freeze whey. However, freezing will weaken the active cultures, so it may not be as effective as a starter for future ferments. Use frozen whey within 1-2 months for best results.

6. What are the benefits of fermenting with whey? Whey provides beneficial lactic acid bacteria, which can enhance the probiotic content of foods, improve digestion, and act as a natural preservative. It also adds a pleasant, tangy flavor.

7. Can I use whey in place of a salt brine for vegetables? No, whey should not replace the salt brine entirely. Salt plays a crucial role in preventing spoilage and maintaining the crisp texture of vegetables. Use a tablespoon or two of whey in addition to your standard salt brine.

8. What should I do if my yogurt whey is milky? Milky or cloudy whey means some milk solids passed through the straining cloth. This whey is not ideal for long-term storage or fermentation, as it can spoil more quickly. It is best to use milky whey within a week in baked goods or other recipes where the cultures will be killed by heat.

9. Is it possible to reuse whey as a starter indefinitely? No. The starter culture in whey can weaken over time, leading to less consistent or failed batches. For best results, use fresh yogurt or a powdered culture to start a new batch after 2-3 generations.

Frequently Asked Questions

Can I use whey from any yogurt?

Yes, as long as it's plain, unflavored yogurt and the label clearly states that it contains live and active cultures. Flavored or sweetened yogurts contain sugars that can interfere with fermentation.

How do I know if my whey is ready for fermentation?

Clear, pale yellow whey is ideal for fermentation. If your whey is cloudy or milky, it contains milk solids and is less potent as a starter, spoiling more quickly.

How long does homemade whey last?

Clear, acid whey can be stored in a sealed glass jar in the refrigerator for several months. You can also freeze it, though freezing can weaken the active cultures.

Can I use pasteurized milk to make whey?

For the traditional clabbering method, raw milk is necessary. However, you can achieve a similar result by adding a live culture like yogurt or kefir to pasteurized milk and straining it.

How much whey do I need for fermenting vegetables?

A good rule of thumb is to add 1 to 2 tablespoons of whey per quart of your brine and vegetable mixture. Remember to also use salt, as whey is not a complete substitute for the salt brine.

Can I reuse whey indefinitely as a starter?

No. The potency of the starter cultures in the whey can decline over time and with successive uses, which can lead to less consistent batches. It is recommended to start a new batch with a fresh culture after 2-3 generations.

What are some signs that my whey has gone bad?

Spoiled whey will have a foul or overly sharp odor, show signs of mold growth, or have an unpleasant taste. Properly stored whey should have a clean, mildly tangy smell.

How can I improve my whey's effectiveness if I froze it?

If you use frozen whey as a starter and the fermentation is slow, you can refresh the culture. Simply add a small amount of new, live-cultured yogurt or a powdered starter culture to your batch.