Fermentation Support Forum

Hi,
I was just making sauerkraut with ton of spices the way I like, and decided spontaneously to add a bit of high quality olive oil to it.

So I searched google about oil in ferments, and reached this article about the dangers of Botulism.
I got scared and think I will trash this batch and just make a new one
http://www.intentionallydomestic.com/is-topping-a-ferment-with-oil-an-acceptable-replacmeent-for-an-anaerobic-environment/

I know that some people top their ferments with oil but I don't do it.

It makes me wonder, because I wanted to try adding other oil-based stuff like Tahini, Peanut Butter and other Nut butters to experiment together with the vegetables, but now I think it might be a problem, as the oil content might change the pH to give life to the bad bacteria.

what do you think?

Thank you ♡

Tom

Good question and I certainly do not have the answer. But, I add oil after fermenting to my giardiniera and keep refrigerated which has never had an issue.

I'd like to know this too. It seems like the botulism caused by oil in ferments warnings started up about two years ago (or maybe that's just when I clued into them). I'd never done anything with oil, so it didn't affect me. But last year, I followed instructions for fermenting chiles in oil and now I'm afraid to try it. :-)

I hope we all could learn the answer as it opens up many flavor possibilities

I also continued this thread with more questions
viewtopic.php?f=7&t=3654

Just my two cents and I am not an expert. The problem I see with the article in the op (If I read it correctly) is that the author assumes that the oil provides a good place for botulism to grow away from the acidic ferment . According to the CDC,a favorable PH range is not enough to grow botulism. In fact there is a list of requirements:

Low-oxygen or no oxygen (anaerobic) environment
Low acid
Low sugar
Low salt
A certain temperature range
A certain amount of water

(https://www.cdc.gov/botulism/general.html)

While the oil would provide a low acidic, low sugar, low salt, and low oxygen environment, it does not provide the needed water, and the only water in contact with the oil in this scenario is either acidic and probably salty (under the oil) or in the presence of oxygen (above the oil) both of which cause problems for botulism. The only possible problem I can see is if water gets mixed into the oil before use (like maybe through infusing the oil?) and if it somehow doesn't separating from the oil. I'm not sure if this is possible without emulsifiers. Solid fats might be problematic though, as they can trap water.

It is true that it is no longer recommended to use oil as a preservation method because is does not prevent botulism, but in the use described here, the oil is not the preservation method. It simply allows the preservation method to take place.

If you can guarantee that the EVOO you are using hasn't been adulterated then I don't see there being a problem. An article I read some years ago suggested that 75% of EVOO sold in the US has been adulterated.

I understand the Romans use to top their casks of kraut with olive oil to prevent spoilage. It does provide a good air tight seal. I've tried it with no ill effects, that was using locally produced EVOO in Australia.