I have about three gallons of clam juice, after steaming about 400 clams. How can I safely keep, can, or store this much juice for further use?
I would suggest to reduce the juice as much es possible (to safe space later on in the freezer or shelf) and either
- freeze it or
- can it (see here and here for canning with a pressure cooker and here for canning with an oven)
Just putting the juice into the fridge is not sufficient. Neither just boiling the juice and filling it into a jar is sufficient because then you are not sterilizing the juice but only pasteurizing.
I'm not much for bivalves, so I can't say that I've specifically dealt with clam juice before. I would personally consider treating it like shrimp or crab stock ... which is basically the same as I would do for chicken stock:
- Reduce it in a wide pot, to intensify the flavors and reduce the total volume to store.
- Freeze it in assorted containers, based on how I'm likely to use it.
My understanding of clam juice is that it's generally has a more 'fresh' flavor to it, so it's possible that reducing it might be a problem. If that's the case, freeze what you can fit in your freezer, then use the rest of it to make a soup, risotto, paella, or similar.
Canning might be possible, but being a meat both, it likely requires pressure canning, which most people don't have the equipment on hand for.