I make green curry paste with green peppers as main ingredient. I put all ingredients in the processor, and keep the paste in a closed jar in the fridge. It stills smells fresh after 10 weeks. Can it be kept for that long? Why (not)?
I would suggest 4-6 weeks. I buy all natural, preservative free green curry paste all the time. The packaging suggests refrigeration once opened up to one month. Most foods without the help of preservatives don't last much longer than a month under refrigeration. The curry paste may not spoil per se, but the quality does degrade significantly. Green curry paste is naturally very strong in the odor department, so it can smell fresh long after it is. I'd bet that if you compared it to a freshly made batch you'd tell the difference.