Heat 1 litre water in a large & wide sauce pan. Once it reaches a boil, add 4 teaspoons of Kashmiri chai leaves. Make sure to use a medium - large saucepan.
Turn the heat to medium, and let the mixture boil for 10-15 minutes till it reduces to about half the initial amount. This usually takes 10 minutes if you are boiling one litre of water but can take longer if making a larger quantity. The initial mark at the edge of the pan can be used as an indicator.
Turn heat to low and add baking soda. The soda will bubble up and there will be a hint of pink around the edges. This is what contributes to the pink hue in Kashmiri Pink Chai. Too much baking soda can result in a bitter after taste so be careful when adding.
Cook this mixture on medium heat for 2 - 3 minutes and it will turn into a dark brown shade with hints of red. Turn off the heat, and strain the Kashmiri Chai leaves.
At this stage, cold water is added to the tea mixture while the tea mixture is aerated. This step is known as ‘phaita lagana’ in Urdu, and is similar to how Malaysia teh terik is made. It means to pour and re-pour the tea from a height. It can be done with a ladle, a mug or by using two pots. This will aerate the tea creating a frothy layer on the chai. As you keep aerating the tea, you will notice the color of the chai mixture changing to a dark-reddish brown. The traditional method of doing this aeration can take 10 - 15 minutes easily, but my quick and easy method cuts this time to less than a minute!
Quick and easy method: Use a commonly found kitchen appliance to mechanically do the tea aeration instead of doing it by hand. Such as an electric hand whisk (my preferred method), a hand held milk frother, or an immersion blender. Strain out the tea leaves. Add ice cold water 1 – 2 cups at a time and turn the appliance on for a few seconds. Repeat till the tea concentrate changes into a dark-reddish brown color and there’s a frothy layer on top. It's also possible to use a regular wire whisk - still requires muscle but easier than using a ladle.
Traditional method: Take a large spoon or soup ladle and stir the tea mixture by pouring and re-pouring it from a height. Pour and re-pour using one hand and add ice-cold water slowly from the other hand. Continue doing this for at least 10 - 15 minutes as a light layer of froth forms on the chai, while the concentrate changes to a reddish brown colour.
At this stage, the kahwa for the Kashmiri Chai is ready and can be poured in a jug or a glass bottle and kept in the fridge for upto 2 weeks. Based on the quantity in the recipe you should have around 1 litre of kahwa.
Whether you use the traditional method or the quick and easy method, make sure you use a big saucepan. The aeration technique will cause a bit of splatter.