In this post, I lay out a simple experiment to develop a variety of recipes for sodium-free canned pickles. By pickles, I mean sour dills. And by canned, I mean preserved so that they don’t have to be refrigerated.
This post is just the background on what I’m proposing to do, and why I’m proposing what I’m proposing. Just a way to get my thinking straight. I’ll actually be making the pickles tomorrow.
If you just want to know what the actual options are, skip to the end of the post, where I lay out tomorrow’s experiment.
Background
I do only the simplest form of home canning, processing acidified foods in a water-bath canner. Mostly, lacto-fermented cucumber pickles (Post G23) and purple cabbage sauerkraut (Post G29).
I take an occasional walk on the wild side. Of which, the tastiest and prettiest by far was fermented cherry tomatoes (via self-sufficient me). Green tomatoes and summer squash also turn out well.
But I never, ever deviate from the instructions given in the USDA Guide to Home Canning (available on-line at this link). This is purely from a desire not to die an untimely death from a potentially humorous cause. It’s also because some canning advice you see on the internet is … wait for it — wrong. No surprise there, I guess. And not just wrong, but occasionally dangerously wrong.
For example, I do my fermenting in half-gallon Ball jars, as shown above. But I can them by the quart or pint, in accordance with the USDA Guide. If the USDA says that half-gallons aren’t safe for canning, I don’t use them for that purpose.
But today I’m going to make one small exception to my usual practice of following the USDA Guide to the letter.
All the standard dill pickle recipes from USDA and other reputable sources have a ton of salt in them. Either fermented or “fresh pack” (i.e., vinegar) pickles. The standard recipes result in pickles with roughly the same amount of salt in the final product as commercially-prepared pickles. (See below for calculation).
I want some decent-tasting home canned sour dill pickles, without the salt. Can that be done?
I’m sure it’s technically feasible to make canned sour dill pickles with no salt, because I can see a commercial product that does just that. The question is whether I can preserve cucumbers out of my garden as canned no-salt sour dills. And still be willing to eat them afterwards.
Salt is not necessary for safe fresh-pack (vinegar) pickles. Vinegar is.
But the rationale for the 50/50 vinegar-to-water rule is a complete mystery.
For fermented pickles, the salt is a safety measure, and per USDA and other reputable sources, cannot be reduced without risk. Salt suppresses the growth of unsafe bacteria at the start of the ferment.
But for fresh pack (vinegar) pickles, the salt has little to do with safety. It’s there for the flavor and texture only. (That appears to be true, by the way, of the salt in all fresh-pack canned vegetable recipes.)
As this is a deviation from USDA gospel, let me start with citation as to source of what I just said. The gist of it is that the safety factor in fresh-packed pickles comes from the acidity. As long as they are sufficiently acid, they are perfectly safe without the salt. (The cutoff for “high acidity” foods for canning is a pH of 4.6 or lower.)
All reputable source say more-or-less the same thing: You can safely remove salt from a fresh-pack (vinegar) pickle recipe, as long as at least half the canning liquid is standard 5% vinegar.
Salt can be removed from most fresh-pack or "quick" pickles without affecting the safety of the product if the recipes contain as much or more vinegar than water or other liquid.
Source: Oregon State University extension service.
Use the exact amount of vinegar stated in each recipe, or an unsafe product may result. Salt or sugar can be decreased in fresh pack pickles with safe results, but pickles may lack some characteristic flavor and texture.
Source: University of Wisconsin extension service.
Any fresh-pack pickle recipe that calls for as much or more vinegar than water and provides a finished product with at least 1/4 cup of 5 percent acid vinegar per pint jar of pickled products can be safely made without salt.
Source: Colorado State University extension service.
I particularly like the CSU advice above because it directly addresses something omitted in the other bits of advice, which is that the cucumbers themselves are more-or-less pure fresh water. As any canner will tell you, about half of a jar of whole pickles is cucumber, the rest is brine. The CSU formulation says that at least one-quarter of the entire finished jar of cucumber pickles must be 5% acidity (i.e., standardized) vinegar. The other formulations — that half the picking liquid must be vinegar — those are approximations that assume you are making whole pickles.
Here’s where this takes a turn into the weird. Where does that “50% vinegar” rule come from?
- Everyone agrees that the safety comes from the level of acidity.
- Everyone agrees that you’re safe as long as half of your canning liquid (or one-quarter of the volume of the finished jar of canned produce) is standard (5% acidity) vinegar.
- Everyone agrees on the definition of “high acid” food (safe for canning without added acid) is food with a pH of 4.6 or lower.
- But a 25/75 mix of 5% vinegar and water is vastly more acidic than pH 4.6.
And by vastly, I mean that the pH of the resulting solution barely budges when you dilute vinegar 25%/75% with water.
This is an example of why I follow the USDA guidelines to the letter. There’s no amount of arithmetic, or reasoning, or anything else available to the home canner that would let you second-guess that 50% vinegar rule. I can only guess that it comes directly from USDA trials. And that you break that rule at your peril.
First, the entire dilution-and-pH thing is nowhere near as straightfoward as you might think. And it’s not the math. Once you understand that pH is an inverse log-10 scale, if you’re good enough with math, it’s no problem to take a guess based on math alone. It’s the chemistry. A weak acid will not completely “dissociate”, when in fairly high concentration. Only a bit of it “dissociates” (breaks apart) to form the hydrogen ions that make the solution acid. The more water you add, the more of the underlying acidic chemical dissociates. The upshot is that the reduction in acidity that you get, from diluting an acid solution, is far less than what you would calculate merely from the dilution alone.
I found the full and correct calculation at this site. Using the formulas there, you’d expect 5% acetic acid solution to go from a pH of 2.41 to a pH of 2.71 if you diluted it 25%/75% with water. (Math not shown). That’s a near-perfect match for somebody who actually did the experiment, in the context of home canning (this reference).
Although I can’t measure the pH accurately, I can assure you that the pH of a 25%/75% vinegar-water mixture is below 3.0. That’s because I tested it using the pH paper that I occasionally use when canning. Here’s the 5% vinegar solution and the pH papers.
Here’s the results of pure vinegar, pure water, and 25%/75% vinegar/water solution. Note that the third one remains so acidic that it’s below the pH 3 lower range of this variety of pH paper.
As you can also see by piling up the strips at the end. Anything that touched the vinegar or vinegar solution remained solid brown — pH 3 or lower. By contrast, the strip dipped in the (presumably pH 7 or so) pure water is off the scale at the other end, pH above 5.5.
Next, I will point out that almost all vegetables are more acidic than ordinary tap water. For example, on this list, which appears to match other lists I’ve seen, raw cucumbers have an average pH of 5.5, which is acid. Adding cucumbers to a vinegar solution will dilute the acidity of that solution even less than adding neutral (pH 7) water. So you don’t require a high initial acidity of the pickling brine in order to offset the alkalinity of the stuff being pickled.
One possible reason for the 50% vinegar rule is that this is a safety factor for areas of the country with highly alkaline water. The highest pH I have stumbled across for alkaline tap water is 8.5. I can’t even guess how to do the calculation, but plausibly diluting vinegar with alkaline water at that level might raise the pH of the resulting solution closer to the pH 4.6 cutoff for safe canning.
Finally, I wonder if the high acidity of the pickling brine is required to ensure that the entire piece of pickled produce ends up with a sufficiently high acidity. That is, maybe it’s not about the average acidity of the resulting jar of pickles, maybe it’s about ensuring that the acids penetrate well enough so that the center of the biggest pickle in the jar has sufficiently low pH?
Beats me. All I know is, that’s the USDA rule. So minimum 50% vinegar in the brine, that’s what I’m going to do.
NaCl substitutes – the shortest section of this post.
If you’ve ever looked at sweeteners, you immediately realize that …
- There are a bazillion different sugars (sucrose, fructose, dextrose, lactose, maltose, …)
- There are half-a-bazillion different artificial and non-sugar sweeteners.
- The sweetening power of each one has been accurately assessed and is public knowledge.
In short, if you want to make something taste sweet, you have an entire arsenal at your disposal, and you can easily calculate how much of any substitute you need in order to make something taste as sweet as table sugar (sucrose).
By contrast, if you want to make something taste salty without using table salt (NaCl), here are is your options.
- Potassium chloride (KCl), which tastes OK in sufficiently low concentrations.
- Calcium chloride (CaCL2), which may or may not impart much of a salt flavor, but is mostly harmless in low concentrations.
- Lithium chloride (LiCL), which will kill you. But at least you’ll still be enjoying the taste of salt up to the point where you croak.
- Unobtainable exotic chemicals that you’ve never heard of and that nobody uses as a salt substitute.
In short, if you look at anything marketed as a dietary salt substitute in the U.S., it’s potassium chloride. Or a mix of potassium chloride and table salt. Or that, plus other incidental chemicals that are more-or-less impurities. Or it’s a shaker full of spices that have nothing to do with salt, with the idea being that if food is spicy enough, you’ll forget about salt.
Upshot of what I can find: If you want a palatable NaCL subtitute, the sole option is KCl, up to about half the concentration at which you’d use NaCL. Beyond that, most people report off flavors, typically described as “metallic”.
Keeping your pickle firm.
Besides taste, the other thing that salt does for pickles is that it keeps them crisp. Or, at least, avoids them turning to mush in the canning process. Even if you don’t miss the taste of salt, a common complaint about low-salt or no-salt pickles is that they have an unpleasantly soft texture.
There are two ways commonly used to make low-salt or no-salt pickles that get around this issue of poor texture. Neither of which is acceptable in this case.
- Make refrigerator pickles. These aren’t canned at all, they are just cucumbers (plus spices) in vinegar, refrigerated. This isn’t a bad concept, but the shelf life in the fridge is typically listed at 4 to 6 weeks. And they take up space in your fridge.
- Make sweet pickles. I note that the only USDA recipe for a reduced sodium dill pickle is, in fact, a sweet pickle. I believe that the high sugar content, in that case, serves the same texture-preserving role as salt in traditional dill pickles.
I want a canned sour pickle. But even in this much tougher case, there are some alternatives that can help preserve the texture of the pickle without use of NaCl.
Calcium chloride, a.k.a., Pickle Crisp. This is a commercial canning product specifically to help keep pickles crisp. And, it’s the only crisping agent in the one variety of salt-free pickles that I have found for sale. Based on the comments on that product, you can (sometimes) get a crisp pickle using calcium chloride alone.
Interestingly, the USDA limit on calcium chloride in canned tomatoes (0.4% solution) is in the neighborhood of some recommendations for use of Pickle Crisp. That works out to three-quarters of a teaspoon per quart, which appears to be the recommended amount of Pickle Crisp in some canning recipes. Everything you ever wanted to know about Pickle Crisp, you can find at this reference.
Tannic acid (grape leaves, oak leaves, cherry leaves, tea leaves, etc). This is an old-time solution that is typically mentioned only in the context of fermented pickles. The idea is that including some natural source of tannin appears to increase the crispness of fermented pickles. Some writeups are here and here.
The mechanism of action is explained here, in that tannic acid inhibits the enzymes that make pickles soften. But that source (Penn State extension service) says that as long as you cut off the blossom end of the pickle, tannins do nothing for a fresh pack (vinegar) pickle. The reason is that for fresh-pack pickles, it’s the heat that causes the pickle pectin to soften. Tannin does not prevent this process.
Pasteurization instead of boiling-water canning. This consists of processing jars of pickles for 30 minutes at 180-185F, instead of 15 minutes (for quarts) at 212F. This avoids the high temperatures that break down pectin in the pickle and soften it.
The problem here is that pasteurization is recommended as safe only for some pickle recipes, and not for others. In particular, the USDA guide does not mention pasteurization as an option for processing their reduced-sodium pickles. There is no way to tell whether that means it’s unsafe, or whether the USDA simply never tested that combination of lower-salt recipe and pasteurization processing. In particular, the Oregon State University document referenced above says this:
Do not use low temperature pasteurization method for processing pickles when making reduced-sodium pickles.
That’s pretty clear. Still don’t know if that’s because this has been tested and is known to be unsafe, or because this hasn’t been tested and therefore is not known to be safe. For sure, if it’s the latter, I’m not going to test it on myself.
Liming. Arguably the premier old-time method for ensuring crisp pickles was to lime them. That is, soak the cucumbers in a solution of calcium hydroxide, rinse them thoroughly, and process into pickles. This introduces calcium into the pectin of the pickle and keeps that firm. Even now, you will see comments by seemingly knowedgeable canners stating that liming guarantees a crisp pickle, almost regardless of the type or processing method.
Pickling lime is readily available, but experts no longer suggest liming pickles. The reason is that calcium hydroxide is strongly alkaline. If any of it remains on or in the cucumber, it can reduce the acidity of the brine enough to allow botulinum to flourish. (It is also, incidentally, kind of nasty stuff to work with.)
I’m not sure how big a problem this is. The most quantitative statement I found was “only a few cases have been reported”.
That said, it is no longer a recommended practice. Yet, the product continues to be available and some home canners continue to use it. Interestingly, the one recipe I found on-line for limed pickles was for pickle chips. With pickle chips, I think it’s harder to make the argument that lime may remain lurking somewhere in the rinsed pickles.
Alum. I’m not going to go there. That’s another one that works for fermented pickles, but based on reputable sources is useless for fresh pack (vinegar) pickles.
Ice. One technique that I see mentioned incidentally in several sources is to soak the cucumbers in ice water for (say) five hours before canning them. I have yet to see even one explanation as to whether or how this works.
One commercial supplier suggests this, but it looks like it’s only a way to chill recently-picked produce (Mrs. Wages, this page). So this may be akin to old advice to chill just-picked corn in ice water, to stop deterioration of the sugars in the corn. And that, somehow, this has morphed into general advice to put your cucumbers in ice water, no matter the source.
Toward a no-salt home canned pickle recipe
Source: USDA, via Google search.
Let me be clear that if you want to reduce the sodium in your diet, regular pickles are off the menu. For example, some versions of the DASH diet, for high blood pressure, limit sodium to no more than 1.8 grams per day. Problem is, one large traditional pickle can give you more-or-less your entire day’s allotment of sodium. (Note that the pickle above is not some gigantic whopper, it’s a 4″ pickle weighing in at just under five ounces.)
Salt is more than just sodium, so to convert any weight of sodium to the weight of table salt (NaCl) that generates it, you have to multiply by a factor of 2.5. And so, when I take typical values for commercial pickles, they work out to a 9 grams (a half-tablespoon) of salt per pound of pickles.
Near as I can tell, the USDA recipe for regular fresh-pack (vinegar) pickles has almost exactly the same salt content as the commercial pickle measured above. That’s a little hard to tell, because with that main recipe first you pre-soak the pickles in salt brine, then you can them. But assuming that the final product ends up a uniform amount of salt in the brine and the pickle, then the USDA recipe results in the same nine grams (half-tablespoon) of salt per pound of pickles.
Based on that, how low is the sodium in the USDA recipe for low-sodium pickles? That recipe, from the USDA guide, appears little different from their recipe for sweet pickles. Their low-salt pickle recipe calls for:
4 lbs (3- to 5-inch) pickling cucumbers
6 cups vinegar (5%)
6 cups sugar
2 tbsp canning or pickling salt
Knowing that the pickles themselves account for half the volume of the finished product (the brine is the rest), then that works out to be one-quarter tablespoon per pound of pickles. Or half the sodium of a regular pickle.
To which my response is, great, I can have two pickles a day and max out my sodium allotment, instead of one. That does not solve my problem.
And so, for the first time ever, I’m going to try something that’s really unlike anything in the USDA Guide to Home Canning.
For salt flavor, my sole option appears to be potassium chloride, at up to half the concentration of NaCl found in regular pickles. I’m not sure I’m willing to use that much.
I can also throw a bit of NaCl in. After sifting through all of the above, I have to wonder if the high salt concentration of standard pickles isn’t mostly a byproduct of the desire for crispness, rather than any mandatory component of the flavor profile. So if I can manage adequate crispness by other means, maybe just a touch of salt (NaCl) will give me a decent flavor profile without a huge sodium load.
For pickle crispness, for fresh-pack whole pickles, the only guaranteed safe and effective method is Pickle Crisp (calcium chloride). But per USDA guidelines, I can use that at a rate up to 3/4 tablespoon per quart (considerably higher than what’s on the label, but mentioned as acceptable by the manufacturer, in one seemingly-well-informed blog post cited in the Pickle Crisp section above).
The only other crispness technique that is known to be safe, and not known to be ineffective, is a long ice-water bath prior to canning. I just have a bad feeling that this is folklore, derived from the useful practice of plunging fresh-from-the-summer-garden produce into ice water to stop deterioration. I’m not sure it’s going to do me any good to buy a bunch of pickling cukes at the farmers’ market and treat them to an ice bath when they get home.
I’d say that a lime pre-soak comes in at a distant third. By reputation, it absolutely works. But it carries some un-quantified risk of botulism. Maybe trying a batch of pickle chips with that method would not be out of the question. (It seems plausible that upping the acid content of the brine might work, but not if the issue is cavities within the pickle that get filled with lime and remain at too low a pH.)
Bottom line: When I boil it all down, spices and flavorings aside, there really aren’t a lot of options for safe home-made canned no-salt/low-salt sour dill whole pickles.
- The brine will be at least half vinegar.
- Add some potassium chloride for salty taste, but not too much.
- Maybe add a touch of salt (NaCl).
- Add pickle crisp (calcium chloride) up to the USDA limit for crispness.
- Maybe chill in ice water a few hours before canning.
And that’s about it.
For the first run, I’m going try to make these salt-free. My canner fits seven pints. That suggests a 2x2x2 design, with one empty cell.
- Two levels of pickle crisp (quarter-teaspoon versus three-quarter teaspoon per quart).
- Two levels of salt substitute (potassium chloride, to be determined).
- Ice water pre-soak, or not.
That’s eight combinations. Omit the jar with the lowest levels of everything. So no jar with low pickle crisp, low salt substitute, and no ice. Make up the other seven, can them, and see how they taste.
That’s tomorrow’s experiment.
