Cilantro Pesto - Canning Question

[FarmFresh]

Hello all! Long time lurker, first time poster here!

I am in need of advice/input on canning a Cilantro Pesto recipe I developed. The recipe is a basic pesto recipe (including olive oil and garlic), subbing cilantro in place of basil. The problem is the acid level is too low to safely can. My first inclination was too add lemon juice, but with inconsistent acid levels in lemons, that idea was nixed.


I have Citric Acid (powder form), but now I am just down to figuring out how much to use. If i know the pH of Citric Acid, can I just do the math on my batch size to calculate the amount to use or am I overlooking something???


Any one have any ideas or suggestions??


Thanks in advance for your help!!!

[CWS4322]

I freeze my pesto with a layer of olive oil on top. Works for me.

[FarmFresh]

Yes, that works well, I often freeze it in ice cube trays, then pop them out and store in a large ziploc in the freezer so I can grab what I need for pasta, etc. The reason i am looking for a method to make it shelf stable is that I make 500-600 jars of jams, jellies, sauces, pickles, beans, etc. each year and would like to add this to my line-up, just trying to find a safe way!

Thanks for your quick response!

[GLC]

"How do I can oil with herbs? Can I can pesto?
Herbs and oils are both low-acid and together could support the growth of the disease-causing Clostridium botulinum bacteria. Oils may be flavored with herbs if they are made up for fresh use, stored in the refrigerator and used within 2 to 3 days. There are no canning recommendations. Fresh herbs must be washed well and dried completely before storing in the oil. The very best sanitation and personal hygiene practices must be used. Pesto is an uncooked seasoning mixture of herbs, usually including fresh basil, and some oil. It may be frozen for long term storage; there are no home canning recommendations."
National Center for Home Food Preservation | Canning FAQs

Extension agents seem unanimous that there is no safe home canning method. I know it's done commercially, but even then, they seem to use extra salt to cover themselves. I see that Classico, in addition to salt (580g in 62g of pesto), uses citric and lactic acids. And commercial canning can use higher temperatures and can be made to operate in a sterile environment that would be impossible to duplicate at home.

Apparently one of the concerns is that it is so thick that it would be difficult to heat throughout.

[jennyema]

The garlic is also a botulism risk

[GLC]

Lots of warnings, but considering the amount of garlic used, there should be a goodly number of cases of botulism associated with it. Let's look.

Garlic-in-oil associated botulism: episode leads to product modification.
Morse DL, Pickard LK, Guzewich JJ, Devine BD, Shayegani M.
Source
Bureau of Communicable Disease Control, New York State Department of Health and State University, Albany.
Abstract
In February 1989, three cases of botulism occurred in persons who consumed garlic bread made from a garlic-in-oil product. Testing of leftover garlic-in-oil showed it to have a pH of 5.7 and to contain high concentrations of Clostridium botulinum organisms and toxin. This was the second episode of botulism associated with a low acid garlic-in-oil product which needs constant refrigeration. In response, the Food and Drug Administration has taken steps to prevent a recurrence by requiring that microbial inhibitors or acidifying agents be added to such products.

Yeah. Garlic shouldn't be kept in oil without constant refrigeration.

[Botulism an a 38-year-old man after ingestion of garlic in chilli oil].
[Article in Danish]
Lohse N, Kraghede PG, Mølbak K.
Source
Skejby Sygehus, Infektionsmedicinsk Afdeling Q, Laegevagten i Arhus.
Abstract
Botulism is a rare but potentially fatal disease caused by toxins produced by Clostridium botulinum. We report a case of botulism in a 38-year-old man after eating canned "garlic in chilli-oil". The patient was treated with antiserum. The diagnosis was confirmed by detection of botulinum B toxin by a bio-assay and growth of Clostridium botulinum from the food left-overs.

There's that garlic in oil again.

Bottled Garlic
Bottled, chopped garlic-in-oil mix was responsible for three cases of botulism in Kingston, N.Y. Two men and a woman were hospitalized with botulism after consuming a chopped garlic-in-oil mix that had been used in a spread for garlic bread. The bottled chopped garlic relied solely on refrigeration to ensure safety and did not contain any additional antibotulinal additives or barriers.

Definitely a regular theme. Plenty of other reports about garlic in oil. Makes sense. Botulism wants an low-acid anaerobic environment to thrive. So anything in oil that doesn't feature high acidity is in play. It's not the garlic itself at all. I find no reports of botulism traced to plain fresh garlic.

But it got me thinking about how I handle garlic, which is most often to smash the pods under the blade of a knife to pop the skin off. That's the only thing I treat like that. I don't wash them, so whatever is on the skin is nicely distributed into the mashed garlic, and botulism is found in soil. Not a botulism thing, unless it's going into a preserved preparation, but a thing nevertheless.

[Dawgluver]

Hoo boy. Just freeze the pesto with the layer of oil on top.

[FarmFresh]

Hmmm.....so that gets me thinking of flavored olive oils sold on shelves. In fact, I have them in my pantry now with basil, garlic, and cilantro. Never any issues, of course, but that does not necessarily make them safe I guess.

I am still curious to know if anyone has canned anything using the powdered Citric Acid.......anyone????

[jennyema]

Originally Posted by FarmFresh

Hmmm.....so that gets me thinking of flavored olive oils sold on shelves. In fact, I have them in my pantry now with basil, garlic, and cilantro. Never any issues, of course, but that does not necessarily make them safe I guess.

I am still curious to know if anyone has canned anything using the powdered Citric Acid.......anyone????

Botulism spores come from the ground,so anything grown in or near the ground can carry them. Botulism thrives in an anaerobic environment like oil. Commercially prepared flavored pils generally have been processed at high heat or acidified (with citric acid!) to kill the bad stuff.

Homemade oils ate another story. They need to be kept in the fridge and then only for 10 days or so.

Botulism can kill you or leave you on a respirator or dialysis. It's nothing to take lightly.

I have no experience using citric acid in canning but if the government suggests that there's no safe way to can, then maybe freezing is a better idea.

[GLC]

Thinking about what else is often packed in oil, I thought of sun-dried tomatoes. But apparently the fact that they are dried (no water - botulism organisms need water) and that processing frequently includes a bath in boiling vinegar before going into the oil has prevented problems. And I would assume the fact that they are not grown actually in the soil is a big factor. A major botulism outbreak was traced to onions left for a time in cooking oil, so there's a root foot sitting in oil again. But commercial herb flavored oils likely use completely dried herbs, depriving the bacteria of water. And, of course, not a root plant, and herbs can be effectively washed first.

Now, while peanut butter, being essentially an oily produce pack, might be suspect, there are far fewer reports of botulism associated with it. There are, though, a number where contaminated open jars were to blame, presumably unrefrigerated. But it may be that, because the peanuts are roasted before processing, there's not enough water to support much microbe activity. And heating to roasting temperature destroys the bacteria and the already produced toxin, although NOT the spores. But the disease is caused by ingesting the bacteria. The human immune system takes out the spores before they can reform as bacteria.

(Infants have immature immune systems, hence the caution about honey, although most infant cases result from inhalation of spores, something that isn't a problem for health adults. Honey is a poor environment for bacteria, though.)

So whatever retards the growth of bacteria is a big help, which means refrigerated storage. And most botulism cases are still traced to home-canning. I suspect the sterile conditions possible in commercial plants but impossible at home means a lot in terms of stray botulism spores floating around the environment looking for a place to grow.