Close cousins in the large, extended family of probiotics – curd and yoghurt are often mistaken for each other. However, while one adds that signature tart kick to a glass of lassi, the other brings a delightful, velvety creaminess to fruit parfaits. We’re taking a quick look at all the differences between curd and yoghurt.
With the growing popularity of all things fermented across the globe, the cold-storage aisles of grocery stores have been flooded with a flurry of colourful packages of probiotic goodness of late. Each come tall claims of healthy digestion and immune health, slapped with varying numbers of CFUs as well as calorie and protein percentages. And whether you’ve recently hopped on the health-food train or are looking to mix things up in your everyday probiotic ritual – it’s worth understanding just how that jar of curd – specifically Indian – can be wildly different from the eclectic set of yoghurts on display most everywhere.
What is curd?
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Broadly, curd refers to curdled milk. This occurs when rennet or an acid like lemon juice is added to the milk – causing it to go sour and form thickened, solid substances of protein that separate from the whey. This process is often the first step to making cheese, especially cottage cheese or “paneer.”
Alternatively, however, the term curd also points to a fermented milk product that’s made with the addition of the lactobacillus bacteria. The process relies on factors like temperature and humidity, with the milk first being boiled and then cooled down. This is called dahi across the Indian subcontinent. Interestingly, reports state that using pasteurised or homoogenised milk can lead to less-than-desirable results.
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It’s also important to note that there’s a third form of curd – fruit curd – that is a dessert spread typically made with citrus fruit, egg yolks, and sugar. This recipe originates from England and is used in several baking recipes. In this story, however, we’re spotlighting dahi.
How to make curd
To kick things off, you’d need to make a starter by dropping a few red chillies or their stems into warm, boiled and cooled milk for some hours. Once it transforms into a wobbly, pudding-like structure, you’ve got something to work with for your next few batches.
½ litre whole milk, starter culture, thick-bottomed pan, food thermometer (optional)
- In a clean pan, add the milk and begin to heat it on a low-medium heat.
- Stir occasionally to ensure the bottom doesn’t burn.
- Once the milk comes to a boil – you’ll notice froth and bubbles – switch off the heat. You could also check to ensure the temperature is between 185 and 204 degrees fahrenheit.
- Set the pan aside and wait until it’s lukewarm. A classic way is to dip a clean finger to check. It should be warm, not hot to touch. Alternatively, you could ensure the temperature is between 102 and 111 degrees fahrenheit.
- Take a few spoons of the starter you’d made earlier and add to the milk. In the winter 2 is recommended whereas the summer only needs about 1. This is because warm temperatures speed up the rate at which the bacteria work.
- Mix well and transfer to a clean bowl – terracotta, steels, clay, or glass.
- Cover with a lid and leave at room temperature for four to seven hours or overnight.
What is yoghurt?
This refers to a semifluid fermented milk product that’s smooth and mildly sour in flavour due to its lactic acid content. Like curd, it could be made using cow, buffalo, or goat milk. The process of making this fermented product is quite specific and requires a starter of lactobacillus bulgaricus and streptococcus thermophilus.
Other types of bacteria may be added, along with sweeteners and other additives. There’s several types of this, based on the process it’s made, the nutritional content, and other factors. Additionally, depending on the type used – these can be lactose free, full-fat, or low-fat. This includes
- Traditional: This is the classic version that’s got live and active cultures with a smooth, creamy texture. Not as thick as other types on this list, the classic rendition retains all the health benefits of milk. A cup has about 107 calories and 10 grams of protein.
- Greek: One of the most popular options, especially in fitness circles, Greek yoghurt is strained to separate the whey liquid from the protein – resulting in a thick, creamy, cheese-like consistency. It has a strong tangy flavour and offers about 13 grams of protein for 80 calories.
- Australian: Like the classic rendition, Australian yoghurt is unstrained. However, several recipes call for heating the milk to about 185 degree fahrenheit to create a better, creamier texture. A cup offers about 10 grams of protein at about 120 calories.
- French: Instead of being made in a large pot and then transferred to a container, French yoghurt is cultured straight in individual-sized containers that it will later be sold in. Unstrained, the texture is creamy and smooth while the flavour isn’t too sweet. A small (150 grams) serving will offer about eight grams of protein at 160 calories.
- Icelandic: This yoghurt is mildly tangy in flavour and more dense than Greek yoghurt in texture. The process that it’s made is much like that of cheese, however considering that it is consumed like yoghurt, it’s categorised as one as well. Interestingly, it takes nearly four cups of milk to make one cup of this yoghurt. Hence, it offers a whopping 17 grams of protein at just 100 calories.
Besides these, yoghurt can also be made with coconut, almond, cashew, or most plant-based milks. They can also be flavoured.
How to make yoghurt
2 litres of whole milk, the fresher the better; 3-4 tablespoons plain whole milk yoghurt or live and active cultures, heavy-bottomed pan, food thermometer
- Bring milk to a simmer in a pan until it starts bubbling around the edges (180-200 degrees fahrenheit)
- Stir occasionally to prevent burning
- Remove the pot from the heat and allow it to cool until lukewarm. You should be able to dip your pinky finger in for 10 seconds. (110-120 degrees fahrenheit)
- Transfer half a cup to a small bowl and whisk the yoghurt culture or yoghurt in.
- Stir this back into the other warm milk batch and combine well before wrapping the pot in a large towel or placing it on a heating pad. The idea is to keep it someplace warm – your oven with the light turned on works as well.
- Let this sit for 6-12 hours until it’s thick and tangy. The longer it sits, the more of these qualities it adopts. Transfer to the refrigerator and chill for at least four hours before digging in.
Key differences between yoghurt and curd
- Process of making: While both involve heating and cooling the milk before fermentation, yoghurt needs to be wrapped in a large towel and refrigerated before consuming. The milk is heated to a lower degree with yoghurt and the final product is often strained. In addition to this, yoghurt requires a specific starter culture while the culture for curd can be made at home from scratch.
- Types: While curd – or dahi – has only one type broadly, certain cultures strain it further or heat milk slightly longer to make mishti doi. Yoghurt, on the other hand, spans several types and often comes in varying flavours.
- Flavour: While curd is typically creamy, mellow, and mildly sour – depending on the fermentation time, yoghurt is acidic, creamy, and inherently sweet.
- Nutritional value: A cup of curd comes with 98 calories, 5 grams of protein, and three grams of fat. Curd helps aid digestion and offers small percentages of calcium and vitamin A and D. A cup of yoghurt, meanwhile, offers about 10 grams of protein at 107 calories.
- Place of origin: Different cultures have different renditions of yoghurt while curd is primarily a creation of the Indian subcontinent.
- Uses: Curd is used in a series of Indian delicacies like raita, kadhi, lassi, and pakoda. Yoghurt, meanwhile, is had as is or combined with granola or slathered on pancakes.
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