Keeping extra sauerkraut brine

This year was exceptionally wet and the water content of my cabbage was very high. I had so much brine from my sauerkraut that I’ve been storing the excess in a jar in the fridge and using it as a starter for other fermentation projects. My question is how long will this brine stay viable like this? Should I feed it like one does with a sourdough starter? Thanks much.

I have some from last years (2018) batch of kraut.  I'm still drinking it.

Well Anne, the simple answer is yes.  Here's two links for more specific instructions.  Good luck.  https://www.culturedfoodlife.com/can-you-reuse-the-brine-for-cultured-vegetables/    and    https://www.wellpreserved.ca/fundamentals-fermentation-can-re-use-brine/

Thank you, that is helpful!