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Sep 3, 2009 11:16 AM

What is the acid or pH level of hot peppers?

I'm (again) considering canning or somehow preserving the hot pepper bounty I have.

It appears that low-acid foods are prone to botulism; peppers (ie jalapenos and habaneros) have more vitamin C than citrus fruits (, and citrus fruits aren't, as far as I understand it, considered low-acid.

If anyone can lead me to a source which actually has the acid or pH level of hot peppers (we're currently growing jalapenos, habaneros, and black pearls), I would really appreciate it.


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  1. Peppers are low-acid foods, so in order to can them, you will have to acidify them -- add an acid in some form: lemon juice, vinegar, etc.

    The canning and food preservation websites have lots of available info.

    Here's a scientific article related to your question -- it also recommends acidifying your

    You may also consider another "preservation" system -- freezing, drying, smoking, etc.

    Or, for example, you may prepare the peppers for use in a dish -- making a puree, a salsa -- and then preserving *that.* Good luck.

    11 Replies
    1. re: maria lorraine

      I'm stopping at the pharmacy to pick up some litmus paper tonight and will report back.

      1. re: Caralien

        habanero seeds: 6.0 (acid)
        habanero skin+olive oil: closer to 6.5 in color (slightly acid)
        olive oil: 7 (neutral)

        this is with a soil test kit.

        will try the jalapenos next

        (I was told I couldn't find litmus paper unless I went to the hospital pharmacy, so this is what I'm testing with)

        1. re: Caralien

          Use pH strips. Just a caution that those chile pepper pH readings indicate very low-acid foods. You will need to add a powerful acid to create an canning environment in which botulinum and bacteria cannot grow.

          Also, chiles are usually pressure-canned to be safe. Check the current chile canning guidelines with the USDA or with a University Extension. Sorry to stress this, but canning chiles is not a food you should even think about preserving improperly. This is nothing to fool around with.

          By the way, this current thread from Melanie Wong is very informative about pH testing strips for canning. You may wish to post there as well.

          pH test strips to measure range of pH 3 to 6?

          1. re: maria lorraine

            I still plan to stop at the hospital's pharmacy sometime soon to check the ph (for curiousity sake). What I'd like is to find the perfect recipe for adding enough acid without having the flavour of vinagre or lemon juice overpower the flavour of the peppers, particularly now that our pepper plants are seriously exploding with ripe fruit!

          2. re: Caralien

            You do understand that while 6.0 is below neutral and therefore acid, that isn't acidic enough for safe canning, right?

            Tomatoes are fairly acidic and only need a little extra acid (if at all) to make them safe, but peppers aren't even close. To make peppers acidic enough to can, you would definitely taste it. Frankly, you'd be better off freezing your peppers, for purest taste. (And it's easier!)

            1. re: Karen_Schaffer

              I do get that it's not safe to simply put them in oil (even though we haven't died from last year's version which was sliced, shaked in sea salt, and covered in olive oil)

              What is the minimum ratio of vinagre or lemon or lime juice to add per x amount of peppers? Freezing is okay for some peppers, but with the pint I've just harvested, I'd like to find the best method possible to keep the integrity of the flavour. It's likely I'll save the seeds to stuff into soil to test whether they can grow (our last experiments are now sprouting under the basil plants).

              1. re: Caralien

                I want to reinforce everyone's cautions to you, Caralien.

                Please check with the canning resources about this. I'm gathering you have not done so. This is important.

                If your peppers are a 6.5 pH, to be safe means you need to increase the acidity to about a 4 pH, or best of all 3.4. Since the pH scale operates exponentially, in powers of 10, just like the Richter scale, pH 5.5 is 10 times more acidic than 6.5, ph 4.5 is 100 times more acidic.

                That means packing the peppers in a vinegar, and pressure canning. If you do not have a pressure canner, you will need to buy one -- there is no alternative here -- or preserve your peppers using another method, like freezing.

                Colorado State University has a good Extension program that gives instructions for canning chile peppers. Go here for more info, and remember
                to be safe:

                And please read this about Botulism, also from the Colorado State Extension:

                1. re: maria lorraine

                  I am not a fan of vinagre, so will do what i can to avoid having the flavour of the peppers ruined with vinagre.

                  I have read links previous posts the risks involved with botulism. Thanks for the additional reminder. What it appears you are saying is that all non-pressure canning methods (ie traditional canning) are not safe? Also, link 1 demands that I use "tested recipes", which means just about anything (tested by whom?). From link 2, there are pickling recipes, which are fine if I wanted gardinera, which I don't. Link 3: I read botulism articles about once a month (as with articles regarding other food borne illnesses and sanitizing everything and not eating street food because it too will make me sick and/or kill me; the writer of Continental Drifter had horrible foodborne illnesses in nearly every chapter).

                  What I would really love to get is a ratio of pepper to acid to make it safe so I don't kill anyone, self included. I really have no desire to get a pressure canner. Does anyone have a ratio for dummies or lazy cooks? I would really like to know the minimum possible because I am not a huge fan of vinagre (unless to marinade pork) or sour, and know without question that fresh citrus juice molds, and cooked becomes both bland and bitter. Is there a calculator somewhere with the amount of citric acid (lemon salt) for peppers to get the right ph?

                  1/4C pureed hot pepper+___ (measurement) citric acid/other acid = safe ph

                  Has anyone successfully made a botulism free non-pickled pepper preserve? I'm nearly at the point of slicing it all up, freezing on a pan, and putting the slivers into a jar to be picked out with knife/fork/tweezers at needed.

                  Apparently the recipes I read for our basil (washed, dried, pureed with olive oil and sea salt, frozen in ice cube trays) were safe and tested by many. I had hoped it might be the same for the peppers.

                  1. re: Caralien

                    I bought the Balls Blue Book of Canning a few months ago and its a great source of information. I fire roasted my homegrown peppers (hot banana & poblano) and added jalepenos and some even hotter peppers (long red things) purchased at the farmers market. After fire roasting them I peeled the skins off and used a recipe out of the above mentioned book that basically consisted of a water/vinegar/salt mixture and put them in Balls jars. I used the boiling water canning method which according to the book is safe as I introduced an outside source of acid 'cos peppers are low acid. I also processed them for about 30-40 minutes. They are still doing fine months later and I'm about to enter them into the county fair next week. When I plan to use this winter I will rinse off the vinegar solution or if in something like salsa or soup I won't worry as the vinegar solution can't be tasted. The moral of the story is that it is not a pure vinegar solution but mixed with water so you don't have that horrible vinegar taste going on.

                    1. re: MRich33392

                      that's good to know regarding the rinsing!

                      On this site ( it appears that per the Blue Book, hot peppers (particularly thin skinned ones) should be dried or frozen although some people believe that freezing turns it to mush. I'm not sure if roasting would work either, as my skin usually starts becoming flush while I'm chopping some up to add to my lunch (1 whole one, way too much; 1cm stub, very hot in cooked food, with face getting flush on and off for remainder of day); in essence, dry roasting these would require a spot far from the house because they really are that hot (a tiny sliver is all my husband can take), so roasting them in the oven indoors would smoke us out of the house, and the grill is on the porch where we spend most nights right now, so it too is off limits for the smoke.

                      But then there was the idea of preserving the peppers in vodka, which may be the method I use.

                  2. re: maria lorraine

                    I sliced up the peppers, shook them in sea salt, then doused them with the juice of 1 lime (ph 2.0). Then covered that with olive oil.

        2. One word for your peppers: Giardinera. No cook canning. Basically vinegar, salt, and oil. You can turn them into an all purpose type condiment that will last for a long time - at least until next year's crop is ready. I make this every year.

          3 Replies
            1. re: Caralien

              Here's a recipe I started with, but I only use recipes for starting points. I never use bell pepper or onion in mine. Use what YOU would like, not me or anyone else. I also don't use a lot of celery, and I like to spend a little on good black olives for mine. I also use jarred chopped garlic ( and lots of it) it also goes into the mixture to soak overnight. Use a food processor to chop these things up, or it gets tiring. Chop them up separately since they wiil be uniform that way. Since carrots are harder than peppers, if you chop them in the processor at the same time, your carrot will be in bigger chunks than the peppers. I use EVOO only in mine. I would let it sit in the fridge for at LEAST two weeks before trying it. The flavors really start coming together then. Should easily last for a year in the fridge, and still be good&crunchy. Oh yeah, I use dried basil in mine too.

              1 red bell peppers, diced
              8 fresh jalapeno peppers, sliced
              12 fresh seranno peppers, sliced
              (use whatever peppers you have, this is just a guideline. I regularly use habaneros, serranos, birds eyes - whatever I've grown in the garden, and can get from my csa guy - he's actully growing me some bhut jolokias this year!)
              3 celery stalk, diced
              1 medium carrot, diced
              1 small onion, chopped
              1/2 head fresh cauliflower florets, chopped small
              1 cup salt
              water to cover

              3 cloves garlic, finely chopped
              2 tablespoon dried oregano
              2 teaspoon red pepper flakes
              1 teaspoon black pepper
              1 (5 ounce) jar pimento-stuffed green olives, chopped
              1 1/2 cup white vinegar
              1 1/2 cup olive oil

              Place into a bowl the green and red peppers, jalapenos, celery, carrots, onion, and cauliflower. Stir in salt, and fill with enough cold water to cover. Place plastic wrap over the bowl, and refrigerate overnight.

              The next day, drain salty water, and rinse vegetables. In a bowl, mix together garlic, oregano, red pepper flakes, black pepper, and olives. Pour in vinegar and olive oil, and mix well. Combine with vegetable mixture, cover, and refrigerate for 2 days before using.
              Makes approx 3 qts

              1. re: gordeaux

                thank you very very much!

                (I too am not very good at following recipes, but will do my best)

          1. My company manufactures and sells pH papers so I thought I'd jump into this thread. We do sell to individuals but our single boxes are too large for the casual user. We sell to some homebrew shops who repackage our papers into smaller packets. That's probably a good choice for someone who needs only a few strips. Also, those stores tend to carry the pH ranges you are looking for.

            As for using them to determine the pH of your peppers, I asked around the office some and this is the consensus we came up with. You can try one of 2 methods to test the pepper. Either cut the pepper open and lay it on the pH strip or puree the pepper and dip the strip into the puree. Using a puree will give you a more homogeneous reading and, to my way of thinking, greater consistency.

            None of us know for sure if the pepper puree will be a buffered or unbuffered solution. Pretty much every pH paper strip on the US market is intended for testing buffered solutions. If, when you test, the colors on your strip run you have an unbuffered solution. Your reading then will not be completely accurate. It may, however, be close enough for you to work with.

            I don't really recommend, as someone on another thread suggested, using a pH meter. The cheap pH pens are notoriously inaccurate and the moderately priced meters require maintainance in the way of buffer solutions, calibration, and meticulous cleaning of electrodes. Far too much effort and too much room for error, as far as I'm concerned.

            Please remember, I know pH - I don't know a thing about canning. I don't want to be responsible for anyone getting botulism! But I'd be happy to answer any question about pH testing or pH strips, if I can.

            2 Replies
            1. re: rockycat

              I would be curious to find out any of your results if you or your colleagues happened to test some peppers! Please share if you do! (even if off the cuff with a recommendation regarding personal testing not to be accepted as possibly accurate for the home market)

              1. re: Caralien

                We've been growing jalapenos and assorted Thai and Vietnamese peppers this season. I'll try to remember to bring some paper home tonight (Spouse is a homebrewer so we can always use it) and see what I come up with.

            2. I've had to order ph strips from Edmond's, as no one in town carries them. We decided to go overboard an order 5 packs of 100, $16 including shipping. Will report back with pureed or smooshed habaneros

              (one pharmacy told me it would be $50 per pack of 100; the others sent me to the hospital; the hospital let me know that they didn't carry it, and the pharmacies should have called before sending me over!)

              2 Replies
              1. re: Caralien

                pH strips are fun, but you do realize that there's not much point in continuing to check the pH of the peppers by themselves, don't you? They are NOT acidic enough to can by themselves. Period. None of them will be. Check if it amuses you, but I guarantee you'll never get a reading in the safe range below 4. It's just not the nature of peppers.

                Please, go back and read Maria Lorraine's posts and links. She knows what she's talking about. Messing around with potential botulism breeding grounds isn't smart.

                1. re: Karen_Schaffer

                  Please--I've read and re-read all of the posts and links! Thanks for asking me to, again, but I've done so, again and again.

                  I have not found a single site ANYWHERE that lists the ph of hot peppers which have been used to preserve foods for milennia. Have you? Has Maria? NO. All of the sites that list peppers list thick skinned mild peppers.

                  Hot peppers have more vitamin c than citrus fruits--that is a fact. If citrus fruits don't harbour botulism, it is natural to believe that a hot berry--ie hot peppers--wouldn't either. I am trying to find out what is real and not--I have not read a single piece that said specifically that habaneros have a ph above (or below) 4. Or that jalapenos have a ph above 4. If you think ALL of the hundreds (at least) varieties of peppers are exactly the same, well that's like saying that all citrus fruits and all berries (ie tomatoes, peppers, and blueberries) are identical too, even if they don't look, taste, grow, or smell like one another. You don't know this factually (although you guarantee it), and neither do I--that is what I would like to find out since it appears no one else has.

                  Food is dirty, and no matter what you do, you will get sick even in the best of circumstances (I've gotten sick from hospital food as well as from fine dining--it happens). Teetotlers and worrywarts also have a greater tendency towards ulcers and heart-attacks than heavy drinkers and potsmokers, btw.

                  If I really wanted to grow botulism, I would get some raw meat and put it in a jar on top of the stove, or leave it behind the refrigerator; as we were taught that in biology.

                  As I said, I'll publish what I find. Thanks for your support!

              2. Preliminary litmus test:
                Tongue: 7
                Habanero: 3-4 (sliced with litmus paper put into pepper to absorb juices; 5 slices tested)
                Vinagre in pickles: 2-3
                EO Citronella: 5
                Bison Blood: 2-3 (may be wrong due to colour of blood)
                Armpits: 9-10
                White mushroom: 6
                Garlic: 12
                Lime: 2
                Rainwater: 6
                Victory Festbier: 4
                Ricard+ water: 5
                Raw potato: 7

                This is by no means a "real" test by experts, but what I found once the litmus papers arrived. Take it as you will.

                The pesto was thrown out because I can't determine whether it was the bright green from the basil or the colour of the paper

                All vegetables & berries were tested by making a slice with a clean knife and having the litmus paper absorb juices from the slice

                I should add that I waited 30 minutes after getting home to test the peppers. Maybe I'm totally off base. If so, let the litmus paper test me. I promised to publish my findings, and this is what I got. If anyone else gets other findings, please post.