Bulk Chai Concentrate Recipe

Trying to find the best bulk recipe for a chai concentrate and it appears as though buying bulk spices and tea and making your own blend is the best bet but I’m having trouble finding recipes that are for more than 6cups of concentrate. And I’m not sure if the amount of spices/tea scales linearly with the amount of water used. Anyone have a tried and true bulk (>5gal) masala chai concentrate recipe?