Put sugar in a vessel and mix it in the third part of water ( 1 kg sugar in the 300 gm water means half cup water). Put this mixture on the fire and boil it. After a boil, keep it boiling for 5-6 minutes. Take a pinch of this mixture on your hand and rub it on your thumb. If it is sticky then the sugar mixture is prepared. Put off the fire and keep this mixture for cooling.
Wash lemons and squeeze them. Wash mint leaves with water for two times. Peel ginger and wash it.
Make a paste of mint leaves and ginger in the mixer. Use sugar mixture instead of normal water in the grinding. Mix this paste in the sugar mixture, put black salt in it and sieve it. Your lemon and mint concentrate is ready. You can keep it in any plastic bottle and can place it in your fridge. You can use it for a month.