Soak Almonds 3-4 hrs before making Thandai and then peel.
Or you can soak almonds in warm water or microwave, this softens the peel and it comes out easily.
Soak cashews, poppy seeds, green cardamom seeds, melon seeds in water 2-3 hrs before making Thandai.
Drain water from the spices .
Transfer all the ingredients to a grinder. Add about ½ Cup water.
Grind to a fine paste.
In a pan add water and jaggery and keep it for boiling. Once the water starts boiling, add paste. Mix well and cook the mixture on low heat.
Cook till the mixture starts getting thick. If you want to store thandai for about a month, cook it till one thread consistency.
Also, add a pinch of citric acid/sodium benzoate for longer shelf life.
Once done, cool completely , transfer in glass bottle, close the cap tightly and refrigerate.
I like to store the concentrate without sieving. You can filter Thandai concentrate using a muslin cloth and strainer.