I am preparing to make my sourdough wth blue cheese and other ingredients. I have often wondered if blue cheese goes bad. I am certain it does. I keep a large amount in the fridge and I can sometimes tell that after a while it has a malty finish. Once it reaches that point I pitch it and replace. However, I have noticed when I use my vacuum sealer it tends to draw the moisture from the cheese. If I pour off that liquid the cheese seems to last longer. But it still leaves the question at what point does blue cheese go bad?