Probably, but it would need to be pretty cold. If you decide that you want to freeze them, you might need dry ice, but then again I haven’t tried freezing that stuff but when I have handled it it seemed pretty thick.

This FAQ from a miso maker says that it can be frozen.

Can’t be any different than freezing tomato paste. You may want to take the time to divide some of it up into individual servings. That way, you can thaw only what you need. I’ve heard of freezing pesto in an ice cube tray. That might work for miso as well. Worth a go anyway.

Basic Asian seconds the idea that you can freeze miso paste”

“Light shiro-miso paste is mild while the aged, dark aka-miso paste has a… are often available fresh (which you can freeze for later).”

I realise this question was asked an age ago BUT no one has mentioned that miso actually keeps for a very long time, a very very long time, like years, years and years and years, if it is refrigerated. I have a large container of miso in my refrigerator which has honestly been there for a least 12 years and is perfectly OK, truly. Trust me.