Cooking a chicken and vegetable curry using a curry paste

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.

You should definitely have a go at it, but I am afraid your time and effort would be better spent on finding a quality source of pre-made paste. This applies to most Asian cooking pastes and sauces.

In most non-Asian countries you cannot get the fresh ingredients required to make them. If they are available, they generally are not the same variety and quality to make a suitable analogue of the Asian masterpieces.

I live in a country with a sub-tropical climate; we have soil that can grow anything, including really good Ceylon tea leaves, and even Chinese Gooseberries (Kiwi Fruit). 10% of the population is Asian. However, for that recipe, alone, I would be faced with these problems:

• Cilantro (coriander) roots - most growers trim the roots for presentation and because they tend to rot quickly. You can get bottled roots but they are't very nice
• Chillies - There is a reasonable range of chillies available, but which one. Asian chillies have totally diffident taste profiles than our local ones for some reason
• Galangal - you can substitute local ginger which is excellent, but not the same as Galangal. I can get seeds to grow my own but that is even more work, and may still not taste right
• Garlic - local stuff is English style, imported Asian Garlic has been fumigated and stored for too long to be any good. It loses its pungency very fast!
• Lemon Grass - the local stuff is VERY expensive and not quite as pungent as Asian grown variety.
• Shrimp paste - imported from Thailand anyway, hmmmm.
• Kaffir Lime - you can get the leaves, but the fruit doesn't really grow here.

The difference if flavours from herbs and spices growing in Asia and growing in your own local climate is similar to why same varieties of wines taste different too. The soil and weather "makes" the flavours

In general I have found pastes vacuum packed in plastic pouches to be of better quality and freshness than the large jar varieties.

Good luck