Canning 101: Is It Safe to Can Products That Contain Some Oil?

November 2, 2011(updated on October 1, 2018)

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Earlier this week, someone asked a question on the Food in Jars Facebook page about canning giardiniera. It’s a spicy mixed pickled that frequently includes a bit of olive oil. I directed that person to a recipe from a trusted source and she wrote back, questioning the safety of the recipe because of the inclusion of oil.

It was a good question. Lots of people have been told that canning with oil is dangerous and in a sense, it is true. Canning a product that is packed only in oil in a boiling water bath canner is a definite no-no. However, if you’re making a pickle from a tested, trusted recipe that has plenty of acid and it includes a small amount of oil, it is okay.

While I’ve not made the giardiniera that I linked to (though it looks quite good!), I have made a batch of roasted and marinated peppers, following a recipe similar to the ones that Kaela, Shae and Julia posted (they are the jars pictured on the right of the image up top). They turned out just fine. Truly, the only thing you have to worry about when working with recipes that contain small amounts of oil is doing a good job of wiping the jar rims, so that no oil residue is left behind. A small dab of white vinegar on your cloth helps.

One more canning fear put to rest!

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100 thoughts on "Canning 101: Is It Safe to Can Products That Contain Some Oil?"

  • The Blonde Italian makes a pesto for bruschetta and past that has a lot of olive oil in it and it’s canned so something must be okay with it.I read that the oil can cover bacteria molecules and not allow them to get hot enough to kill them .

  • I have made tomatoes with A measure of clarified butter and Olive oil in the batch mix can I candies tomato safely and if not why not

    1. This post details why it isn’t advised to can things containing oil. I don’t know how else to explain it.

  • I read the link on Canning Green Bell Peppers. Thank you for that. It was very informative.
    I forgot to mention that the peppers in oil are hot peppers (not sure if that makes a difference). I see that the recipe for green peppers calls for lemon juice which is an alternative to citric acid in other recipes. I will note this adjustment in my future canings with oil. Thank You

    1. Hot peppers and sweet peppers are both low acid vegetables, so it doesn’t matter which kind you use. Good luck and be safe!

  • Wow, I have been canning peppers in oil -just oil no vinager- for decades. Thankfully I’m still here. Now that I’m concerned if I was to add acid to the bottom of the jar as I do with my tomatoes sauce would that remove any concerns and not compromise the taste. Thanks

  • Hello, I fire roasted a few pints of tomatoes the other day with a lite coating of olive oil, salt and pepper. Then canned them in a hot water bath for 85 minutes. I did use a tablespoon of lemon juice during the canning process. They sealed just fine. Then I read that you should never can products with oil. What is your opinion on this? Do you think they will be fine or should I store them in the refrigerator and use them soon? Thank you, Stacy

    1. It sounds like you only used a little bit of oil, so they should be fine. The warning is more for things packed in oil.

  • I made vegetable recipe For water bath canning that included a half Tb. Of olive oil on top of each quart jar. The jars were processed for 15 minutes and I noticed oil in the canning water.All the jars have sealed successfully but I wondered how that is possible if oil seeped out?

  • Thank you for this info! I have a question, new pressure canner here. What if the recipe called for a small amount of Olive Oil, rims were wiped and all requirements followed, but had some siphoning. I made Frend Onion soup according to the Ball recipe. My jars all sealed, but each jar had a small bit of siphoning. Does the oil cause any concern as far as a true quality seal? Should I be concerned about long term pantry storage safety in this instance? Thank you!

    1. Siphoning is entirely normal and is often hard to avoid. As long as the jars are sealed, they are fine.

  • I I’m thinking about making some home canned soups. I make a chili which is very good but we add olives to it. I’m obviously using olives out of a jar when I add it to it. Is that safe? It has a nice flavor to the chili, but I don’t want this to become a nightmare. Thoughts?

  • I am new to canning. I roasted cherry tomatoes in olive oil then put into sterilized jars (Oil juices and all )and water bathed for 40 min. I was a little bit short on headspace and added some olive oil to fill up. Probably about a tablespoon or more. I also added 1 tsp. salt and 1 tsp. Lemon juice in a 400ml ball jar. THEN while it was processing I read about the oil issue. Is my jar of tomatoes safe processed this way ?

    1. Your jars are quite unsafe. You don’t have enough lemon juice for safety, and the oil is quite problematic. If the jars have been processed for more than 24 hours, I would discard them.

    1. That recipe has a ton of acid and a relatively limited amount of oil. As long as the jars sealed, the finished product should be safe.

  • I have a recipe for marinated mushrooms that contain some oil. Could I substitute carrots for the mushrooms?

  • I have a question which I hope you can answer;

    I was canning tomatoes and did not have enough left for canning a full jar so I put them (uncooked) into a clean empty pasta sauce jar, screwed on the lid and put them in the refrigerator. That was Oct 8th. Are they still good ? Can I cook with them ? I had read somewhere they are only good for 7 days but I also read that if you cook them for 30 to 40 minutes (high simmer) it will kill anything bad. What are your thoughts ?

  • While the water bath preserving method would not be advised, Why couldn’t this be pressure canned?
    I’ve seen a similar product for sale that was made in Europe and was available at the grocery..

  • I’m relatively new to canning, but i was introduced to the process years ago in the university by my roommate who used to bring several jars of stew with her in her box. Stew here is made by pureeing tomatoes, peppers and onions, reducing the mix in a pot, then adding lots of oil and stir frying until dry. she would use this for the four months of the semester, and it was always completely fresh.

    so i dont know why suddenly it is dangerous to can oil, because im not talking about a few table spoons. no. you keep pouring the oil into the puree till it just covers it, then you stir fry.

    however, she always heated the stew in a pot before eating. maybe this killed off any bacteria, but it was definitely not intentional. its just customary to eat food piping hot.

  • My pickled peppers were disqualified from the State Fair as I was told the added oil would disintegrate the rubber seals. Lo and behold, it does! Maybe plastic lids?

  • I have dehydrated tomatoes until they are quite leathery, then massaged and soaked them in vinegar, then put them in canning jars and filled to the top with olive oil, removing as much air as possible.
    Please let me know if this sounds safe to you
    Thanks

  • I just put up some heirloom tomato sauce from this recipe here: http://www.mountainmamacooks.com/2014/09/heirloom-tomato-sauce-canning/

    It has a LOT of onions, garlic and olive oil for a boiling water bath recipe, but also has a ton of white wine and some lemon juice added in at the end. I’m looking at my jars and wondering if perhaps I should toss them in the freezer? They sealed beautifully but there is no such thing as too safe, I suppose…

  • i pickle eggplant……peel and slice into matchsticks, cover with salt for a few hours, rinse and strain, soak in vinegar overnite. Squeeze out the vinegar. Mix eggplant with olive oil and herbs. Pack in jars. I refrigerate instead of processing. Does this sound safe?? My mom did this for,years and years. Never a problem!

      1. If it’s been processed in a water bath canner for 45 minutes already….should I just refrigerate for safety? I already processed the eggplant oil recipe. Ugh. So hard to find the right answer.

  • Marisa, I have a question about an onion jam recipe that I got from a friend who lives in England. I mention where she lives because she states that normally they don’t water bath nor pressure can and store there canned products in the pantry and they are fine with their cooler temps. I might also mention that she is a chef of many years. The recipe is absolutely delish and wonderful, but it contains 6 tablespoons of olive oil. It also contains red wine vinegar, some brown sugar, grenadine, raisins that release their sugar in cooking, of coarse the onions (3 types), garlic, walnuts, and a few spices. My question is “is this considered a small amount of oil” and “would it be safe to water bath or pressure can”? I love this jam as does anyone who has eaten it as a gift. But now I am scared of it’s safety to give as gifts and keep in my pantry over the year. Please help as I am ready to make a batch for this next Christmas season’s gifts and myself (have already bought my onions so need to get it make pretty quick. Thank you so much in advance for any help you can give me.

    1. Kathy, onions are really low in acid, so I’m more concerned about the acid content rather than the presence of the oil. Unfortunately, there’s no way for me to judge the safety of a recipe like this from a list of ingredients.

      1. Thank you Marisa. I guess I’m just concerned if the amount of acid with the vinegar added and the sugars might raise the acid content enough to outweigh the low acid onions and small amount of oil. Guess I need to buy one of the gadgets to test the ph-which since I love gadgets will be fun to get. One last question, does adding brandy to a recipe help with the ph level? Sorry if my questions sound silly or dumb but I am fairly new to canning some of these things. I love your site and so glad I found it. Thanks for what you do for everyone.

        1. Kathy, sugar doesn’t raise the acid content. Only vinegar does. Brandy will help a small amount, but will only be significant if you use a very large amount.

  • Are there any specific quantities available for what is a “safe” amount of olive oil in a canned recipe? As previously mentioned there is a recipe in the BBB for pasta sauce called “seasoned tomato sauce” that calls for olive oil. I assume this is a safe amount.
    It calls for 1/2 cup oil in 45 lbs of fresh tomatoes. I often make batches with only about 15-20 lbs and use 1/4 cup. Is this too much? Is there a ratio of sauce to oil that can give people a better idea what is safe?

  • Hi! I need help. I have some
    Cured ground Spanish chorizo pork in the freezer I want to bottle:
    1. I want to cook and fry and bottle by pressure canning with olive oil so I’m guessing this bad? My pork has Prague powder. Does this make it safe to can on oil?
    2. Do you suggest I just can in water? Or is it ok to pressure can in vinegar?
    3. I am using a pressure cooker, I read that in should add weight to te jiggler? What should be the
    Weight? How long should it be in the pressure cooker? Or how do I tell if the pressure is good.

  • Question – so I have a water-bath canned artichoke recipe from what look like a reliable source (Eugenia Bone’s book) that calls for 3 cups acid (vinegar + lemon) and 1 cup olive oil. I want to omit the oil entirely – would the proper thing to do be to replace that liquid with more acid? Or is water an OK substitute? And a more general question – based on what you’re saying here, that 1 cup olive oil seems like A LOT – the recipe is only for 4 pints, so I’m sure it’ll float in a layer above the vegetables – so how is this not a botulism risk?

    Thank you for any input … love your blog, it is such a valuable resource.

    1. To answer your second question first, the presence of all the acid makes the oil okay. Oil is more of a rancidity risk than a botulism one. If you’re omitting the oil, I’d use more vinegar in its place. However, knowing Eugenia’s work, I am more than certain that the recipe is safe as written. She’s meticulous.

  • Ok…so my question/comment, since we are speaking of oil. I buy my coconut oil, from TT on the internet in 5 gallon buckets. I then melt the oil over low eat in my stainless steel BAP. While the oil is melting I place 1/2 gallon jars in the oven and heat to 250 degrees. Oil is ready – jars are ready – I fill jars and cap with lids and band. When the jar cools the lid seals and the jars are ready for long term storage….this is not really “canning” I am just trying to get a good seal on the jar…and it does work. Any chance of botulism in the coconut oil that I store like this?

  • Hi, I made a wonderful hot(whole) jalapeno pickle recipe last year that called for 2 tbsp of olive oil, along with 3 cups of cider vinegar, garlic and spices. I just finished making a new batch for this coming year. Over time, the liquid has disappeared at the top of the still well sealed jars. I wouldn’t worry if they didn’t contain oil, but now after reading everything about botulism, I am concerned. Some of the peppers are poking up into the ‘air space’ through the little layer of oil. As I said, they are still tightly sealed. Are they safe to eat? Not wanting to kill off my family and friends!!!!

    1. I forgot to say that the two remaining jars from last year are the ones I am asking about. These pickles are processed in a boiling water bath for 10 minutes and haven’t lost liquid in the process…it’s just over the year (I suspect the peppers may have absorbed the liquid)

      1. If the jalapenos were canned whole, then I’m certain that the liquid loss is because the peppers have been absorbing the brine. I’m sure they’re fine.

  • Just got some chopped garlic in to make about 100 jars of garlic dills. The garlic is stored in oil! Can I still use it? My guess is yes as the amount of garlic will be minimal and the jars will be water bathed. What do you think? Many thanks.

  • I have a barbeque sauce recipe that has butter in it. Since it also has vinegar it I assumed it would be safe for canning. Agree?

    1. Terri, it depends on how much butter is in your recipe. If it’s just a pat, it should be okay, but if it’s a significant amount, probably not. Butter is different from oil because it contains milk solids. So it becomes something that can lower acidity and render a product unsafe.

    2. No, not at all ! It is unsafe unless it was safety tested in a lab by a reputable University or Ball.
      The butter can allow botulism to survive. You should toss the jars, do not open or you risk getting potential botulism from just opening them.

  • If you Google what makes oil and fat go rancid you will find out that heat is a large factor in breaking fats down as is light and most importantly oxygen in both air form and water form( the molecule water can be broken into oxygen and hydrogen). In stability, the following fats are as follows: polyunsaturated fats are the worst in terms of stability of molecule then monounsaturated and finally saturated being the longest shelf life. Fats should always be stored in chilled conditions to make them last the longest. Rancid fat is not good for you but is not going to kill you tomorrow if you eat some. Accumulatively it is bad for you and it can deplete your system of fat soluble vitamins and is hard on your body for a number of reasons as many unhealthy chemicals are created in the break down (degrading) of fats. You CAN can meats with pressure cooking which of course will have ( some) fat in the flesh. They just recommend you use lean cuts to can to cut down on the amount of fat that can become rancid and be ingested. If you have to sauté something use saturated fat at a low temp like not over 350 degrees F in coconut oil butter or lard before canning. Which will not break down as easily with the heat of canning and frying and remove as much of the oil before canning as you can and then store the product in cool or cold storage in the dark. Also don’t store them for 2 years. make sure you use it up quickly. Remember that canned products are an anaerobic environment. Adding oil or fat is not going to make it more anaerobic. Canning is the process of driving the ” mechanical” air out of the jar with heat and “pressure canning” does an even better job of it with more heat and more pressure. The idea is that the heat kills both bacterium and fungus spores( mold and botulimun clostridium” in pressure canning. However oils and fats are fatty acid-hydrocarbon chains (lipids) and UV light and oxygen can cause the molecules to break apart. Also the air you drove out in processing is not the only oxygen present. Meat has the ability to store some oxygen in its tisue and water in the liquid in the container is a second source of oxygen that can be stolen from to break down fats and cause rancidity. Water is pretty stable as molecular bonds go but an unstable fat molecule can steel from it especially if exposed to heat or UV radiation. So, the more stable fat you use, and the cooler and darker the environment, the better for shelf stability. Happy canning. Less fat, is better than more, in canning. You can always add fresh oil when you get ready to eat your canned product. By the way, even cake mix and flour can become rancid. Buy flour in small amounts and check the packaging date to get as fresh as you can. Grain has fat in the Germ and the healthiness plummets when that goes rancid. http://www.naturalproductsinsider.com/articles/2009/08/understanding-rancidity-of-nutritional-lipids.aspx
    has a good easy to understand page that explains fat breakdown. Hope this helps to stop the panic on this page :).
    I love science.

    1. Thanks so much for clearing up the confusion. I’ve been canning for six months now and I NEVER can a dish without consulting an online (up-to-date) USDA Canning Guide. It’s saved me numerous times! I recently saw a gentleman called “The Bayou Gardener” on Facebook can mustard greens with a chunk of raw pork at the bottom of each jar. And if that wasn’t enough, I don’t know that it’s really a crime, but he lifted two cooled pressure-canned jars and rotated/shook them up! You love science, and I love reading!

      Thanks again for the invaluable information re fats & canning.

      Lisa

      1. I don’t believe there is anything wrong with pressure canning greens with a bit of meat in them. The canning times are the same for both: 70 minutes for pints and 90 minutes for quarts.

        I DO agree that he shouldn’t be shaking the jars right after taking out of the pressure canner.

  • I have been canning eggplant caponata (diced eggplant, chopped yellow bell pepper, garlic, onion, white raisins roast in oven till tender, salt), a delicious antepasto. I fill the jars with a mixture of canola or corn oil and vinegar. It lasts for at least 6 months in the pantry. After opening it, or if you decide not to can it, it keeps in the fridge for 3 to 4 months, if always covered with oil.

  • “roasted tomato garlic jam that contains olive oil”…”essentially a pickle (lemon juice and/or vinegar) but it has quite a bit of oil in it”… “It never occurred to me that canning with oil might be dangerous!”… “onion jam”…”canned tomato sauce with olive oil…hot packed peppers fried in oil…”…”Great info!!!! I’m Italian, so oil is in everything!!! Thanks!”
    #6-Ryan: NO! you’re creating the perfect home for Botulism! Freeze those things!
    Onion jam should be refrigerated or frozen. It’s suitability for any type of canning is in question not because of acidity or fat, but because of density.

    Marisa, I hope you come back and revisit this post! Obviously you need to define “a small amount of oil” in measurement terms. The above comments are a canning instructor’s nightmare and an accident waiting to happen.

    1. Rebecca, I’m definitely planning on returning to this topic. Just haven’t had the time in the last week. Thanks for the reminder!

  • This summer I pressure canned a tomato soup recipe that contains butter. A few weeks later, I read that canning with butter is dangerous, so I stashed all 10 quarts in the freezer. I’m still too nervous to open them, but reluctant to throw out all the work and time I put into them. Considering that they were pressure canned, then frozen a couple weeks later, I want to think they are ok, but remain wary.

    1. That tomato soup and many of the other posters recipes are really risky. They need to be thrown out. Do not open sealed jars of things as you risk getting botulism from just opening them.
      Pressure canning will not make things with oil safe ! It still is an anerobic condition , which is how botulism grows.
      Please, get yourself some current safe books like the Ball Blue Book and So Easy to Preserve. If you even trust any of the Better Homes, etc. they often have very dangerous recipes.
      I teach food preservation and food safety as a profession. I work at a local University Extension Office.

      1. The Ball Canning book includes a spaghetti sauce that has olive oil in it that requires a water bath of 35 minutes. I would think that it would be safe. There is the addition of bottled lemon juice to each jar to increase the acidity. Hope this helps answer the oil question.

      2. Canning itself _of any kind_ creates an anaerobic condition. The oil does nothing to add to that. That being said, anything that isn’t super pickled _acid_ that has oil in it needs to be pressure canned.

  • Found you through Twitter (thank you, Twitter!) and it seems like perfect timing.
    What a fantastic looking cookbook! Must get a hold of a copy and make this pork.
    Thanks for the introduction to Virgina Willis.

  • I have a great Tex-Mex chili gravy recipe I’d love to can. It stays thick and doesn’t separate, but could it be canned? I will share the recipe if you need me to.

  • Thank you, I had wondered about that too. I have canned tomato sauce with olive oil. Everything bubbled over and leaked out but still sealed! I have six kids…I can’t always make it to the stove in time!

    I also hot packed peppers fried in oil to which I also added a salt/vinegar brine. There seemed to be no problem, but, I always wondered if there was a danger.

    AND I also did this in reused Smuckers natural peanut butter jars with the original lids. My mother was horrified, but when I demonstrated that the only one in the house who could open the jar was my super-fingers-plumber husband, she just grunted.

    1. Marie, I looked at that same onion jam recipe! I was worried too – the recipe has butter and oil. I think I’ll just pressure can it to be safe.

      Jessica, a tight seal isn’t necessarily an indicator of safety. Reusing peanut butter jars for water-bath canning is incredibly unsafe, you should throw that food away. It’s not worth the risk.

    2. Jessica, I had the same question. I have canned tomato sauce with olive oil for the last five years never realizing the possible danger. Marisa, I would like to ask the same question if it is safe? I make very large batches of sauce in 20 qt pots or larger with approx. 1/2 cup of extra virgin olive oil. Thank you!

  • It had never occurred to me that this would be bad. I’ve always eaten canned tonnato that was in olive oil and herbs! Good to know I should watch out!

  • Ah, thanks for this! I was a little concerned about an onion jam I made this summer, even though the recipe came from a Better Homes publication.
    It was so good, it didn’t hang around long enough for me to worry much….

  • It never occurred to me that canning with oil might be dangerous! I’d never heard such a thing. Two years ago I canned some gardiniere veggies, but the recipe didn’t call for oil. However, that same year I canned some antipasto. The recipe was beautiful, and just what my husband would love for evening snacks. The ingredients were canned wholly in olive oil. The recipe called for an extended water bath period. Two years later, the antipasto is still quite tasty!

    1. This is my third year canning Italian Style Green Tomatoes in Olive Oil. The tomatoes “dry” with kosher salt overnight, squeezed dry, then they sit in a white vinegar bath for several hours (overnight), drained. Packed in jars with a good olive oil, then a hot water bath for about 15 minutes. I’ve never had any problem with them. Everyone loves them – no one gets sick. (Perhaps tomatoes are acid, then the salt, and then the vinegar – so perhaps it’s weighed out by all those acids)

      My Grandmother had been doing this since she was a young girl in Italy at the turn of the century (1900). Jars of green tomatoes in olive oil were stored in her basement for months. They probably could have been there longer, only everyone wanted to eat them.

      My pickled Jalapeno recipe calls for some olive oil too. They turn out terrific – the olive oil makes such a difference in the pickling process, adds a great flavor.

      So this is the first I have heard of this! So for over 100 years my family has been doing this – Now I’m a bit nervous! Who knew?!?!

      1. Valarie, the hard truth of it is that we know a lot more about food safety now than we did 100 years ago, so practices that were once common are no longer advisable. The process you describe for your tomatoes is most certainly not recommended by the USDA. However, it’s still a technique that’s used in Italy. It’s a choice that is up to you.

      2. My great nana made sweet hot pepper relish like this – she too was from Italy. She soaked them overnight in salt and cider vinegar, then the next day mixed them with olive oil and other ingredients. I have followed her recipe and now do the hot water bath for 15-20 minutes to shelf can them, but still worry about the oil causing people to get sick. This year I have stored them in the refrigerator rather than on a shelf as that is how Nana stored her peppers – seemed she always had a jar in the frig to pour over our sandwiches and meatball subs. I never asked her how she “canned” or preserved them. Now that I bathed them, is storing them in the frig the right thing to do??? I am trying to find a variety of other methods so no one gets sick that eats them. The oil definitely makes a difference in the flavor so I don’t want to do without it – the only other way I can think of is to can them as relish and then serve them with oil? Interested in others thought about this and canning/storing in frig.

        1. Wish there was a response to this question….as I’m wondering the same….to store in frig after water bath canning or not.

          1. Essentially, there are risks to canning products with oil. If you want to be absolutely, positively safe, you don’t do it. Keeping an oil packed product in the fridge will help with safety, but even that’s no guarantee.

        2. Nobody seems to want to touch this because of the anaerobic environment BUT if you cook above 242f, salt or lemon acidify, bring the oil up to temp,WHY NOT??? If nobody died for hundreds of years and we know so much now then lets publish some STATISTICS ON WHY YOU CAN’T!!!

  • My experience with canning Giardinera with a small amount of oil was that some oil seeped out along with air bubbles during the boiling water bath and the jars ended up with an oily coat the required lots of wiping oi get off. Probably didn’t allow quite enough headspace.

  • Mary: When I first started reading this blog, Marisa had a giveaway for So Easy to Preserve. She went on and on about what a great resource it is. Well, I had the awesome thrill of winning the book and I have to say she was absolutely correct.
    I’m thinking the reason it doesn’t show on the Amazon book sidebar is that the book isn’t available new through Amazon–rather you must go to the Extension’s website to order it. I do see that Amazon lists two sellers of used copies, but maybe it’s too variable for inclusion…

  • I would like to suggest that you include reference to university Extension resources with USDA-tested recipes. Interestingly, when you use Eugenia Bone as your “trusted source for safe recipes” it was Colorado State University Extension that helped guide her in the first place. A very good link for “trusted recipes” is the University of Georgia’s National Center for Home Food Preservation site at http://www.uga.edu/nchfp because in addition to USDA-tested recipes, it has altitude adjustment processing times which is very important for those not living at sea level. Also, for this reason, please add to your cookbook list So Easy to Preserve, produced by Univ of Georgia Extension. Thank you.

  • You can also choose a variation of Giardiniera that doesn’t include oil. Here is mine: http://theprudenthomemaker.com/giardiniera

    I’ve really wanted to do sun-dried tomatoes in oil, but everything I’ve read so far says to just dry them, and then pack them in olive oil in the fridge a day or two before using them. Of course, even just storing the dried tomatoes that long is a bit impossible to me; they’re like candy and I just end up eating them!

  • Could you still preserve certain foods in olive oil, without going through the canning process, and still be safe? Would it need to be stored only in the fridge? I’ve thought about preserving my own roasted red peppers, sun-dried tomatoes and duck confit like that, but now I’m not so sure.

  • I actually had the same concern with a roasted red pepper recipe that I’ve used two years running now (probably the same one above except I grabbed it from Rurally Screwed). The recipe is essentially a pickle (lemon juice and/or vinegar) but it has quite a bit of oil in it so they feel more liked they’re canned in a vinaigrette. I’ve had no problems thus far with the actual canning process or spoilage. However, I have noticed that they go rancid very easily (i.e. the oil gets that nasty off-flavor). I imagine the heating process of the BWB breaks-down the oil some to begin with and then my pantry tends to be warm, which doesn’t help. Last year, I ended-up tossing the last jar because of oil rancidity. This year’s batch is already starting down that road. I may ditch the oil next year altogether in favor of a longer shelf life.

    I also use a couple tablespoons of oil to saute the veggies for my marinara sauce (which I usually pressure-can) and I’ve had no problems whatsoever there. I think the quantity is small enough and with the pressure canning, I feel I have a little extra insurance.

    The only other experience I’ve had with fat is when pressure-canning chicken stock. Unless you have the time to let it sit overnight in the fridge to solidify, some chicken fat inevitably ends-up in the jar. After canning, the fat floats to the top and sits there and can also go rancid if the jar isn’t kept cool. Generally speaking, though, I’ve found the product to be fine when I opened it–even stock opened in late summer that was made from the Thanksgiving turkey.

  • The problem is, oil floats to the top, creating an anaerobic environment, exactly what botulism needs. Yes, if the food is properly acidified it is safe, but there is no way of accurately testing for acidity in a home kitchen. It’s always better across the board to avoid using fats in home canning OR to use a professionally tested recipe that’s been proven to be safe.

    1. Oil floating to the top does not cause an anaerobic environment!
      The process of canning (anything) creates a anaerobic environment.

      I can Bacon, the fattiest meat around.
      It’s not the fat that makes meats dangerous, it’s improper techniques such as time and temp and hygiene that creates the risk.

  • Thanks for this post. I’ve been wondering about that for a long time. Is a little butter in the recipe safe, too?

  • I didn’t know I needed to worry about oil, NOW I’m concerned – ha, ha. I make a roasted tomato garlic jam that contains olive oil. The tomatoes and garlic are slow roasted in the oven, drizzled with olive oil. When I put them in the pot on the stove, I do remove them from the oven dish with a slotted spoon to remove excess oil. From your description, it sounds like it is safe. The recipe makes 3 – 4 half pints, which I water bath. But we love it so much, it hasn’t stayed on the shelf longer than 60 days.

    1. I am looking for this very answer. I wonder if it takes longer than with just tomatoes for a water bath?
      Now I want to know what you eat tomato jam on? I roast them with basil and other seasonings and oil but put it on pasta or use Mexicsan seasonings and put it n Mexican dishes. Never heard of a basil/tomato jam!

      1. remember a water bath only reaches 212f. Botulism dies at 242f. If you salt tomatoes, they will not reach the 212f mark.