A few months ago, I opened a can of anchovies, and to avoid wasting the leftovers, I pureed it into a paste and saved in a container in the fridge, in olive oil.

The anchovies are very salty and the pH is somewhere between 5 and 6, based on a litmus test strip. It's been kept in the fridge the whole time. They also smell fine, no hint of spoilage.

But: could this be a botulism risk? The original product was commercially canned, so it was probably safe (and eating it then was fine). My understanding is that these conditions ought to prevent botulism growth, if there was even any to begin with. But since the consequences are so serious, I'd like to be sure.

1 Answer 1


First a little perspective. Botulism is very rare. According to the CDC in the US:

From 1996 to 2014, there were 210 outbreaks of foodborne botulism reported to CDC. Of the 145 outbreaks that were caused by home-prepared foods, 43 outbreaks, or 30%, were from home-canned vegetables.

So this is not a common occurrence. It doesn't mean we should not pay attention to potential risks, but I don't think canned anchovies are much of a concern. Add to that, the acidic environment that you report, plus the salt content, plus the fact that commercially canned anchovies are processed at a high temperature (and anchovies are not known as a source of botulism), I would say from a botulism standpoint you are safe. I can't, of course, speak to how you handled the anchovies during your processing, but if you were relatively clean, you should not have a problem. I would make sure they are not in the can, and submerged in oil.

Finally, please understand that smell is never a reliable indicator of spoilage. Many things can go wrong with food before you can smell it.

  • My processing was really just a whiz in the food processor in my kitchen. It was clean but not sterile, but definitely aerobic. Then it sat in a plastic container. I actually did cover with oil, but it seems to have been mostly absorbed by the mixture. But wouldn't covering in oil reduce the oxygen, and be more conducive to botulism? Apr 4, 2020 at 15:16
  • @JoshuaFrank botulism spores have to be present and viable for them to produce the toxin. Given the original processing, it would be hard to imagine any botulism spores being present. Covering in oil, in this case, is simply to maintain the freshness of the anchovy.
    – moscafj
    Apr 4, 2020 at 20:05
  • I felt reassured enough by this information that I tried the anchovies and I seem to be fine, so I guess that's the ultimate answer. Apr 6, 2020 at 13:43

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