I keep a a half gallon jar full of salty brine for those times when I need it, whether it is for brining fish or meat, or for fermenting vegetables.
Also, if you prepare the brine you can make sure to have it at a consistent level of salinity. For brining, you want to have a 6% solution.
Here’s how to make a gallon of 6% salty brine. Any salt that’s not iodized will work. Kosher salt is preferred by professional cooks and it doesn’t need any additives to keep it from clumping. However, only Diamond kosher salt has no additives and is the best choice for that reason. Grey sea salt has additional trace minerals, which can be beneficial.
1/2 cup hot water in a measuring cup Salt 8 cups cold water
Add salt to the hot water in the measuring cup until the measure reaches three-quarters of a cup. Done this way, it will not matter what salt you are using, even a kosher salt that is light and flaky. When completed, add the salty water to the 8 cups of cold water and mix.