Hi Merlin,
As you have described it (i.e. simply blended chillies with garlic), I'd also say they would probably "stay fresh" for a few days (maybe a week or so) in the fridge.
Alternatively, you can puree the chillies in white wine vinegar, put the puree into in a sterilised jar, cover it with extra vinegar (to stop the surface going mouldy), and put it into the fridge (I put mine in the fridge, but I'm not sure that this is strictly necessary). It will be preserved indefinitely. I did this, with a kilo of scotch bonnets (that were wrongly underpriced

), and they were still perfectly fine (well, they LOOKED and TASTED perfectly fine!

) well over a year later. Great on cheese on toast too!

......
....and I'm still alive

Alternatively, you can puree the chillies in a little water, freeze them in an ice cube tray (of 1 tsp and/or 1 tbsp sized chunks), remove them and keep them frozen in sealable sandwich/freezer bags (or similar). I also do this with garlic, ginger, coriander (but I don't puree this), etc, etc. It works pretty well I find
