Save the brine?

I've kept a rotating batch of refrigerator pickles for a little over a year now. As I pull pickles for snacking I've adding new vegetables to the brine as we've had excess in the garden. We've been getting much better about eating everything that comes from the garden, and after more than a year I've just emptied my gallon jar for the first time. All that's left is the brine with some dill sprigs. I'm inclined to just keep the whole thing in the fridge till we start having excess again so that I can keep using the same brine.

I think the various vegetables have helped the brine develop a unique flavor. I've had visiting children who wouldn't eat pickles before asking me if I've starting any pickles this year. I just don't see a new batch of vinegar, salt and water being the same. Am I causing any safety hazard if I follow through on this plan?

As you add more vegetables, and then take them out, you are reducing the concentration of salt in the brine. Salt helps to reduce the growth rate of some micro-organisms. I certainly can't address the issue of bio-safety, but you might consider adding a Tablespoon of salt for each 1.6 pounds of vegetables that you add while restarting the fermentation...

Thank you for the reminder. I tend to add the salt to taste, which in my family actually means that I started with a higher than usual salt concentration in my brine, and I try to keep it close to that.

Actually, as I think on it, I may try an additional experiment. If I pull half the brine to a separate container packed full of herbs (many of mine are due a trimming) I think it would create a great marinade, maybe even a salad dressing base or seasoning in it's own right.

I'm picky about the fermentations I like but I'd really like to find more that appeal to me. I feel the weight of missed opportunities in not exploring my options here.

Fermentation with brine is a step by step process.
The salt serves 2 purposes. 1 is to pull water from the contents and to provide a starter environment for the lacto bacteria to thrive in before the bad bacteria can take a hold and thrive thus ruining your ferment.
As the ferment progresses, the ph lowers and that also aids the preservation process.
If you use the old brine with a PH of say 3.4 then you are stopping the flavoring strains that would have thrived from neutral ph until the 3.4. The result would be a different flavor. Kraut can be in the low 3 ph range.
If you had achieved a very low ph, you are basically doing the same as making vinager pickles I would think. Adding the salt is a good idea for preservation and safety though. 5% vinager can be around 2.4 ph