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I grow basil and I have enough that I would like to can some pesto sauce.

I have tried to find a way to can it but I keep hitting a wall.

I would like to give a few cans of pesto to people for Christmas.

Can anyone help me?

10 Answers 10

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I've never seen canned pesto, nor do I know if there is a way to do it safely. I will propose an alternate solution. Have you thought about freezing it? I've had pesto given to me as a gift before, but it was made as normal then frozen in a canning jar. It worked great.

Did some more digging and eventually came across this, from the National Center for Home Food Preservation. In summary, the oil and herb mixture is too low of an acid to prevent development of nasty bacteria.

See similar questions regarding storing/canning stuff in oil for more about why it might be dangerous: - Garlic Infused Oil - Peppers and Oil

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    Canned pesto does exist, that is how it is normally sold in shops, at least in Europe.
    – nico
    Sep 11, 2012 at 5:33
  • A frozen Christmas gift? Now that is a new one on me! Pack it in snow for the ultimate White Christmas :-)
    – TFD
    Sep 11, 2012 at 6:29
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    Definitely freeze it, and consider giving basil infused oil or vinegar (or something else) as a gift instead.
    – lemontwist
    Sep 11, 2012 at 13:18
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    @badp Bottling and canning are basically the same thing - you make sure it's sterile and seal the environment. And canning at home refers to glass jars, not metal cans.
    – Cascabel
    Sep 11, 2012 at 17:43
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    @Aaronut Correct canning = bottling + canning in North America. How many people own and use a home canning machine though? Last time I checked you couldn't can without one? Only place you can get them here is in a Museum! Bottling can be done with recycled jars and lids over and over again. Yes the cooking part and result is the same, but that's like saying riding a bike and driving a motorcycle is the same :-)
    – TFD
    Sep 12, 2012 at 2:06
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I've never canned pesto, but I always make a big batch and freeze it when the threat of the first frost comes:

  1. Make pesto, but leave out any cheese
  2. Freeze ice cube trays or other small containers**, with a sheet of waxed paper pressed on top (to prevent signficant oxidation)
  3. After 2-3 days, release from the container, and put into a zip-top bag, squeeze out the air, and keep in your freezer.

When it comes time to use, take a portion out, and either defrost in the microwave, or toss it in the hot pan after draining the pasta, then stir in the hot pasta to melt it (turn heat to low if you've still got major frozen bits), and stir in your cheese.

** Beware of plastic ice cube trays, as you can easily stain them and leave a lingering garlic flavor. I keep two trays that I use for freezing pesto & stocks, but when I do large batches at the end of the season, I use muffin pans.

As an alternative ... you might be able to can basil oil, where you blanch the basil, then simmer it in olive oil, and strain it before putting up. (I keep mine in the fridge; I've never tried canning it). You can then use it in various dishes, including pesto (using flt leaf parsley for the green, which you can get more easily in the winter). Don't try to make a garlic-basil oil, or you'll have those same botulism risks.

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I think it is mainly the bacteria Clostridium botulinum that you need to watch out for, since it can come from many vegetables and can develop toxins in an anaerobic environment (e.g. in olive oil). It is also not visible and does not alter the taste of the food, and the toxin is one of the most potent natural toxins, so not a bacteria to do any trial and error with. Look for ways of inactivating the spores or lowering pH or adding salt to hinder the growth. I guess that's what the food industry does with their canned pesto. UHT treatment or anything like that.

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I can see several ways to can pesto depending on your comfort level.

1) Can it in balsamic vinegar in a water bath as a thick paste pesto base (there are tiny 1/4 pint jars or use 1/2 pints). Then attach a small bottle of gourmet olive oil and a wedge of parmesan with instructions to mix their own.

2) I personally think that parmesan is dry enough to be pressure canned along with the basil mix because I've done it in homemade pasta sauce, but canning dairy is not recommended by the "experts." Then your gift would be shelf stable.

3) I would also trust adding the parmesan to the vinegar mix with the basil in a water bath because botulism can't survive pure vinegar. Then attach that to the oil bottle (maybe put some in a shot bottle with a fancy label, tie it up with ribbon & instructions).

4) Pre-made pesto -- Some preppers have successfully canned oils and butter (again against advice) and managed it, so a full pre-made pesto is conceivably possible. (Search the Prepper websites)

...BUT in my experience anything I've canned that has a high fat or oil content, like meats, has a certain percentage of seal-integrity risk if the oil was to get under the seal and loosen it. Because that type of seal breach would not be caused by microbial growth inside the product, I do it anyways, but keep the product upstairs to supervise so if a seal loosens I can use it - not tried and true like you'd want to give guests.

... A late reply to the question, but worth exploring. Good luck all! :)

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I use walnuts in my pesto, usually in combination with some pine nuts or cashews, mainly because of the cost of pine nuts ($20 per pound in my neck of the woods) b but I do like the rich taste of the walnuts and cashews combined. Having said this, I have successful canned pesto in a pressure canner with no ill effects -- except garlic breath. This could possibly be due to the acidity of the walnuts. Whenever I'm in doubt when canning, I add about a 1/4 tsp of lemon juice per pint of what ever I'm putting up at the time i.e. applesauce, pesto, bean soup, etc. Works for me. :0)

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  • Are you canning it with oil, or without, as franko mentioned?
    – Joe
    Oct 5, 2015 at 16:59
  • I think "no ill effects" is a very unreliable measure of safety, unless you've done it thousands of times.
    – bdsl
    Sep 3, 2016 at 0:55
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I've long wondered this, too, and your question prompted me to do some digging. This article at eHow seems to indicate that you CAN indeed pressure-can pesto if you leave out the olive oil in the recipe, and then add the oil in when you cook with it:

http://www.ehow.com/how_8323914_can-pesto-sauce.html

I also ran across a random comment in another thread by someone who claims to have been using a regular pressure-canning process for his pesto (including the olive oil) "for years" now with no issues. I think the eHow article and process is interesting. I'm not sure why leaving out the olive oil would be critical, but it's an interesting note.

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  • Leaving out the oil is critical because a large percentage of oil means the pH is high.
    – lemontwist
    Sep 11, 2012 at 14:17
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    @lemontwist the rest of the ingredients in pesto are not necessarily more acidic than the oil. They certainly are not acidic enough to create a botulism-safe environment. The point of leaving the oil out can better be explained with the air which will be left mixed with the pesto, as botulism bacteria are anaerobic. I still don't know if this is enough to reduce the risk of botulism to officially approved levels, and of course a single person can can using unsafe practice for years without experiencing a problem, but you never know you won't be the one to be bitten by bad practice.
    – rumtscho
    Sep 11, 2012 at 15:28
  • @rumtscho, I agree. What I meant to get across was that with the oil in there as the primary liquid the pH definitely won't be low enough, vs. if you used vinegar as the primary liquid it wouldn't be as much of a problem.
    – lemontwist
    Sep 11, 2012 at 20:34
  • Alas the ehow article does not seem to include anything about canning anymore :'(
    – Selah
    Nov 23, 2021 at 0:55
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I would also like to can some pesto - thinking maybe blend basil with a little water, then pressure can and add oil, cheese, and nuts when you open the jar?

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    Hi, Theresa! Welcome to Season Advice! Your answer looks more like a "me-too" instead of an answer that abides to our guidelines. If you have the same problem you can help by researching potential answers and posting the results of your research, or setting a bounty for the question so more people will fill inclined to help! The full guidelines are posted here Sep 24, 2019 at 8:44
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I think that commercial producers must dehydrate the basil first. By eliminating the water before you mix it with oil you would eliminate the risk of mold growth. Then they can use the oil as a preservative. No oxygen permeates the oil to reach the basil after pressure canning it. Once you open it of course you would expose it to air and it would have to be refrigerated. I make herbal infused oil and this it the rule of thumb I follow: dry herbs for oils, fresh for alcohol. There is no spoilage ever. I think I will freeze some and dehydrate the rest to make it the same way I would make an infusion.. with garlic, pine nuts, and Parmesan!

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    the main risk with pesto is that botulism, and botulism prefers a low or no-oxygen environment.
    – SAJ14SAJ
    Jul 23, 2013 at 22:47
  • How does botulism like a low water activity environment, though? Apr 19, 2017 at 14:17
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I’ve found this bit of info on Barilla’s site: “BARILLA SAUCES AND PESTO: MADE ACCORDING TO TRADITION

And when we talk about our sauces and pesto, (…) We use state-of-the-art conservation techniques that make our sauces 100% safe. For example, they are heated to a temperature of from 92 to 95 degrees Celsius and poured into jars, which are specially treated before filling.”

Temperature range is then known.

The interval I’m not sure of. I’m going to do, say 20 minutes in the oven (small jars) to make sure the pesto is evenly heated through.

Seal it immediately and (as my grandma jars jams) tuck the filled jars in a thick blanket to let them cool together slowly (for a 12-24 hours). You might as well add a layer of cellophane (made for jarring) under the lid for extra safety to keep air out.

As for “specially treated jars”, pour boiling water in the jars and over the lids in the sink, leave them for 5 minutes and then you may add whatever. This kills anything in the jar.

Temp range source: https://www.barillagroup.com/en/stories/stories-list/barilla-sauces-when-tradition-and-innovation-meet/

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  • Your proposed process is not safe.
    – Sneftel
    Jun 8, 2022 at 6:15
  • Please let me know the unsafe parts and I shall edit it. I don’t want to spread harm. The temperature is sourced, the jar sterilisation is the way my family does this for generations for jams. I have jars of jams dated 2019 or older being perfectly fine. But again, let me know and let us work this out because I want to jar some pesto and I’m going to start today if no one stops me. Jun 8, 2022 at 7:08
  • Your jam has a low enough water action to prevent botulinum growth. This does not. I can’t believe I have to say this, but: random marketing statements on the internet are not a reliable guide to preventing microbial growth when preserving food.
    – Sneftel
    Jun 8, 2022 at 7:22
  • Ok, you have a point. Still trying to work out a solution. Adding some water perhaps? Jun 8, 2022 at 11:42
  • That would not help. See the other answers. If you want to safely store pesto, use your freezer.
    – Sneftel
    Jun 8, 2022 at 11:55
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Less chance of bacteria forming if the pesto is canned in a regular (not pressure) canner, if you leave out the nuts and cheese and add those ingredients when serving the pesto.

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