Ditto to what Pablo said. I use all but a little bit of a batch of pepper mash, and will then add fresh peppers to the mix, with the proper amount of salt, etc. Mix in the bit of older mash at the bottom, and fermentation begins again. Same concept as when people use the same sourdough starter for bread, for example.
Rocketman, I noticed that you recommended putting the mash in the fridge for long term aging. My last batch of pepper mash was about a year old before I used it in my most recent batch of hot sauce. It had been stored that entire time at room temperature in my cupboard. I assume that the combination of low ph, salt, and the fact that the lactobacillus (I assume that lacto is what is doing the fermenting) has reached a point where it has taken over the mash makes it so that no spoiling or harmful bacteria could survive. I may be wrong, but my year old pepper mash tasted great after over a year storage at room temp.
I usually don't age for this long to begin with, but would like to know if there is a reason why this should not be done. Thanks!