Homemade yoghurt is a delightful and rewarding culinary adventure. Not only does it taste far superior to most store-bought varieties, but you also have complete control over the ingredients, ensuring a healthy and delicious treat. And what better vessel to use than a classic Kilner jar? These iconic jars are perfect for fermentation, offering a safe and aesthetically pleasing environment for your yoghurt to culture. In this comprehensive guide, we’ll walk you through the entire process, from choosing the right ingredients to troubleshooting common issues, so you can create creamy, tangy yoghurt right in your own kitchen.
Why Make Yoghurt at Home?
Making yoghurt at home offers a plethora of benefits that extend beyond just taste. You get to choose the quality of milk used. Organic, grass-fed, or even raw milk can elevate the flavour and nutritional profile of your yoghurt.
You can also control the sugar content. Commercial yoghurts often contain added sugars and artificial sweeteners. Homemade yoghurt allows you to naturally sweeten it, or leave it unsweetened altogether.
Home-made yoghurt also eliminates artificial additives. By making your own, you avoid the preservatives, stabilizers, and artificial colours often found in store-bought options. This is particularly important for those with sensitivities or allergies.
Plus, it’s a cost-effective alternative. Once you have the initial equipment, making yoghurt at home is significantly cheaper than consistently buying it from the store.
Finally, it is extremely satisfying. There’s a certain satisfaction that comes from creating something from scratch, and homemade yoghurt is no exception.
Gathering Your Supplies and Ingredients
Before you embark on your yoghurt-making journey, it’s essential to have all the necessary supplies and ingredients readily available. This will streamline the process and ensure a successful outcome.
Essential Ingredients
The two key ingredients for making yoghurt are milk and a yoghurt starter. The type of milk you choose will significantly impact the final product’s flavour and texture.
Choosing the right milk: Whole milk produces the creamiest yoghurt due to its higher fat content. However, you can also use 2% or skim milk for a lower-fat option. Consider organic milk for a purer flavour, and avoid ultra-pasteurized (UHT) milk, as it may not culture as effectively.
Selecting a Yoghurt Starter: A yoghurt starter contains live and active cultures that ferment the milk and transform it into yoghurt. You can use store-bought plain yoghurt with live cultures or purchase a dedicated yoghurt starter culture. Ensure the yoghurt you use as a starter contains the specific cultures you desire, such as Lactobacillus bulgaricus and Streptococcus thermophilus.
Necessary Equipment
Alongside the ingredients, certain equipment is necessary for a successful yoghurt-making process.
The Kilner Jar: A Kilner jar is ideal for fermenting yoghurt. Its airtight seal helps maintain a stable environment for the cultures to thrive. Choose a size that suits your needs, considering how much yoghurt you want to make at a time.
A Thermometer: A reliable thermometer is crucial for accurately monitoring the milk’s temperature during heating and cooling. A digital thermometer is recommended for its precision.
A Large Pot: A large, heavy-bottomed pot is needed for heating the milk. This type of pot helps distribute heat evenly and prevent scorching.
A Whisk or Spoon: A whisk or spoon is used for stirring the milk and incorporating the starter.
A Heating Pad or Alternative Incubation Method: Yoghurt cultures require a warm environment to thrive. A heating pad, a yoghurt maker, an oven with a proofing setting, or even a well-insulated cooler can be used to maintain the optimal temperature.
The Step-by-Step Yoghurt-Making Process in a Kilner Jar
Now that you have your ingredients and equipment ready, it’s time to dive into the yoghurt-making process. Follow these steps carefully for optimal results.
Step 1: Preparing the Kilner Jar
Sterilizing the jar: Proper sterilization is crucial to prevent unwanted bacteria from interfering with the fermentation process. Wash the Kilner jar and its lid thoroughly with hot, soapy water. Then, sterilize the jar by boiling it in water for 10-15 minutes or by placing it in a preheated oven at 250°F (120°C) for 20 minutes. Allow the jar to cool completely before use.
Step 2: Heating the Milk
Heating and Holding: Pour the milk into the large pot and heat it over medium heat, stirring frequently to prevent scorching. Heat the milk to 180°F (82°C). This step is crucial because it denatures the milk proteins, resulting in a thicker, creamier yoghurt. Hold the milk at this temperature for 10-30 minutes. This prolonged heating further enhances the yoghurt’s texture and helps eliminate any competing bacteria.
Step 3: Cooling the Milk
Cooling Down: After holding the milk at 180°F (82°C), remove it from the heat and allow it to cool down to 110-115°F (43-46°C). This is the optimal temperature for the yoghurt cultures to thrive. You can speed up the cooling process by placing the pot in an ice bath, ensuring the water level is below the milk level to prevent contamination.
Step 4: Adding the Yoghurt Starter
Inoculation: Once the milk has cooled to the correct temperature, gently whisk in the yoghurt starter. Use approximately 2-4 tablespoons of starter for every quart (liter) of milk. Ensure the starter is thoroughly incorporated into the milk.
Step 5: Transferring to the Kilner Jar
Pouring and Sealing: Carefully pour the inoculated milk into the sterilized Kilner jar. Seal the jar tightly with its lid.
Step 6: Incubation
Creating the Right Environment: The incubation process is where the magic happens. The yoghurt cultures need a warm and stable environment to ferment the milk.
Using a Heating Pad: Wrap the Kilner jar in a towel and place it on a heating pad set to low.
Using an Oven: Preheat the oven to the lowest possible setting for a few minutes, then turn it off. Place the Kilner jar inside the oven. You may need to repeat this process periodically to maintain a consistent temperature.
Using a Yoghurt Maker: If you have a yoghurt maker, follow the manufacturer’s instructions for incubation.
Using an Insulated Cooler: Line a cooler with towels and place the Kilner jar inside. Pour warm water (around 110°F/43°C) into the cooler, ensuring the water level is below the jar’s lid. Close the cooler and monitor the water temperature, replenishing it as needed to maintain a consistent warmth.
Step 7: Fermentation Time
The Waiting Game: Allow the yoghurt to ferment for 6-12 hours, or even longer, depending on your desired tartness. The longer the fermentation, the tangier the yoghurt will become. Start checking the yoghurt after 6 hours to assess its consistency and flavour.
Step 8: Refrigeration
Stopping the Process: Once the yoghurt has reached your desired consistency and tartness, transfer the Kilner jar to the refrigerator. Refrigeration will slow down the fermentation process and allow the yoghurt to thicken further. Allow the yoghurt to chill for at least 2-4 hours before consuming.
Tips for Success
Making yoghurt at home is relatively straightforward, but a few tips can help ensure consistent and delicious results.
Maintain a Clean Environment: Sterilize all equipment thoroughly to prevent contamination.
Use a Reliable Thermometer: Accurate temperature control is crucial for both heating and cooling the milk.
Avoid Overheating the Milk: Overheating can scorch the milk and affect the flavour of the yoghurt.
Maintain a Stable Incubation Temperature: Fluctuations in temperature can hinder the fermentation process.
Be Patient: The fermentation process takes time. Avoid disturbing the yoghurt during incubation.
Troubleshooting Common Yoghurt-Making Issues
Even with careful attention to detail, occasional issues may arise. Here’s how to troubleshoot some common problems.
Thin or Runny Yoghurt: This can be caused by using skim milk, insufficient heating, or an inactive starter. Try using whole milk, holding the milk at 180°F (82°C) for a longer period, or using a fresh starter.
Grainy Yoghurt: This can be caused by overheating the milk or using a UHT milk. Ensure you are not overheating the milk and avoid using UHT milk.
Bitter or Sour Yoghurt: This can be caused by over-fermentation. Reduce the fermentation time in the future.
Mold Growth: This indicates contamination. Discard the yoghurt and thoroughly sterilize all equipment before trying again.
Variations and Additions
Once you’ve mastered the basic yoghurt-making process, you can experiment with various flavours and additions.
Sweetening Options: Add honey, maple syrup, or fruit preserves to sweeten your yoghurt.
Flavour Extracts: Incorporate vanilla extract, almond extract, or other flavourings.
Fruit and Granola: Top your yoghurt with fresh fruit, granola, or nuts for added texture and flavour.
Yoghurt Cheese: Strain your yoghurt through cheesecloth to create a thick, creamy yoghurt cheese.
Storing Your Homemade Yoghurt
Homemade yoghurt can be stored in the Kilner jar in the refrigerator for up to two weeks. Ensure the lid is tightly sealed to prevent contamination.
It is also essential to note that the yoghurt will continue to ferment slowly in the refrigerator, becoming slightly tangier over time.
In Conclusion
Making homemade yoghurt in a Kilner jar is a rewarding experience that allows you to create a healthy, delicious, and customizable treat. By following these steps and tips, you can enjoy creamy, tangy yoghurt made with your preferred ingredients, free from artificial additives and excessive sugars. So, gather your supplies, embrace the process, and embark on your homemade yoghurt adventure today!
What type of milk works best for homemade yoghurt in a Kilner jar?
Full-fat milk generally produces the thickest and creamiest yoghurt. However, you can use semi-skimmed or even skimmed milk for a lighter version. The fat content directly impacts the richness and texture, so consider your preference when choosing. UHT milk is convenient because it’s already sterilized, simplifying the process, but pasteurized milk also works well; just ensure it’s heated to a sufficient temperature during preparation.
Avoid using raw milk directly unless you are experienced in safely pasteurizing it yourself. Ultra-pasteurized milk can sometimes result in yoghurt that doesn’t thicken as well, due to the higher heat treatment affecting the proteins. Experiment to find which milk type consistently delivers your desired yoghurt consistency and flavour profile.
How important is the temperature when incubating the yoghurt?
Maintaining the correct temperature during incubation is absolutely crucial for successful yoghurt making. The ideal temperature range is typically between 108°F (42°C) and 115°F (46°C). This range allows the yoghurt cultures to thrive and effectively convert lactose into lactic acid, thickening the milk and giving it the characteristic tangy flavour.
If the temperature is too low, the cultures will be sluggish, and the yoghurt may take significantly longer to set, or it may not set at all. Conversely, if the temperature is too high, it can kill the cultures, preventing fermentation. A reliable thermometer is your best friend in ensuring consistent results, and using an insulated container or yoghurt maker helps maintain a stable temperature throughout the incubation period.
What kind of yoghurt starter should I use?
You can use commercially available yoghurt starter cultures, or even plain, unflavored yoghurt with live and active cultures from the store. When choosing a starter, ensure it contains viable bacteria like Lactobacillus bulgaricus and Streptococcus thermophilus, as these are the primary bacteria responsible for yoghurt fermentation. Check the expiry date on the starter to ensure its potency.
If using store-bought yoghurt as a starter, opt for plain, unflavored varieties without added sugars or preservatives. Using a high-quality starter culture or yoghurt will result in a more consistent and flavourful homemade yoghurt. You can even use a batch of your homemade yoghurt to start the next one, but after several generations, the culture may weaken, so periodically revert to a fresh starter.
How long should I incubate the yoghurt in the Kilner jar?
The incubation time varies depending on the temperature, the type of starter culture used, and your desired level of tartness. Typically, yoghurt needs to incubate for 6 to 12 hours. Start checking the yoghurt after 6 hours; it should be starting to thicken and have a subtle tangy aroma. The longer it incubates, the thicker and tangier it will become.
It’s important to monitor the progress regularly. Gently tilt the Kilner jar to check the consistency; it should be semi-solid and wobble slightly. Over-incubating can result in overly tart yoghurt with a whey layer on top. Once it reaches your desired consistency and tartness, stop the incubation process and refrigerate immediately to halt further fermentation.
How do I prevent the yoghurt from becoming too sour?
Controlling the incubation time is the primary method to manage the sourness of your homemade yoghurt. As the yoghurt cultures ferment, they produce lactic acid, which contributes to the tangy flavour. Incubating for longer periods results in more lactic acid production and a tangier taste. Regularly checking the yoghurt during incubation will allow you to stop the process when it reaches your preferred tartness level.
Another factor is the temperature; higher incubation temperatures can speed up the fermentation process and increase the sourness. Additionally, the type of starter culture can influence the final flavour profile. If you consistently find your yoghurt too sour, consider using a different starter culture or reducing the incubation time. Immediately refrigerating the yoghurt when it reaches the desired tartness will also help to slow down further fermentation.
How do I store the finished yoghurt?
Once the yoghurt has reached your desired consistency and tartness, immediately transfer the Kilner jar to the refrigerator. Cooling it down rapidly will halt the fermentation process and prevent it from becoming overly sour. Ensure the lid is tightly sealed to prevent the yoghurt from absorbing odours from the fridge.
Homemade yoghurt, when stored properly in the refrigerator, typically lasts for up to two weeks. Check for any signs of spoilage, such as mould growth or an off-putting odour, before consuming. It’s also a good practice to reserve a small amount of the finished yoghurt to use as a starter for your next batch, ensuring you have a consistent culture to work with.
Why is my homemade yoghurt runny and not thickening properly?
Several factors can contribute to runny yoghurt. One common reason is an insufficient incubation temperature. If the temperature is too low, the yoghurt cultures won’t be as active, and the milk won’t thicken effectively. Another cause could be using milk that is not fresh or has been previously opened for an extended period. The quality of the milk plays a significant role in the final texture.
Also, ensure your starter culture is potent and viable. An expired or weakened starter may not contain enough active bacteria to ferment the milk properly. If you are using store-bought yoghurt as a starter, ensure it has live and active cultures and hasn’t been overly processed. Try increasing the incubation time or using a different batch of starter culture to see if this improves the thickening process. If problems persist, consider using a different milk type, ideally full-fat and very fresh.