The form of the sweetener does make a difference, though research in this area is just beginning.

Fruits preserved with Splenda are not an issue. Essentially what you're doing is canning fruit in water; the impact on texture and keeping qualities once opened will be the same as if just water had been used.

But pickles present special problems. Note this account from the NCHFP of problems with pickled beets [I've italicized for emphasis]:

"Recently, a question was asked regarding changing the sugar in pickled beets. The person made pickled beets using fructose and Splenda® in place of the sugar. A few weeks later, the lids popped loose and juice was coming out while transporting the jars to a relative in another state. This never happened when regular sugar was used. What could have gone wrong? There is rarely one simple answer to these situations. Common solutions include bacterial growth, poor seal, chips around the jar rim, food particles on the jar rim, old lids, lifting the jars by the lid instead of the jar rim, or not following manufacturerÂs directions in preparing the lids. In this scenario, however, another factor must be considered as the problem. The use of different sugars. Sugar will dissolve in water. When this occurs, it will raise the boiling point of water. Different sugars have different molecular weights per molecule. Therefore, this weight difference may raise the boiling point only 1°F or it may raise it 5°F as examples. This change affects how long a food must be processed to be considered safe. In the case of the pickled beets, the fructose and Splenda® are quite different in weight than sugar. Therefore, using the same processing time from the original recipe was probably not adequate. The beets were beginning to show signs of spoilage. This is one example why we recommend using tested recipes from sources such as the USDA Complete Guide to Home Canning or from the Cooperative Extension Service."

So I wouldn't make a pickled recipe with Splenda (for canning) unless it had been specifically developed for that product. However, I know Ken has had good luck with Splenda-sweetened pickles and his take on this issue may be different.

Beverly Alfeld's new book Pickles to Relish does offer several recipes with Agave substituting for sugar. However, I don't know the pH of Agave nectar and whether she's using Agave in pickles with a low enough pH to allow for differences in sweeteners.

She does caution to be very careful in subbing one sweetener for another. For example, she has customers who are interested in maple syrup as a natural sweetener for pickles, but maple syrup in several cases raised the pH to the unsafe level.

So again, until more is known, I'd stick with recipes tested for the sweetener you would like to use. But that's just my point of view. You might see if your library can obtain Alfeld's book so that you can take a look at the recipes which call for Agave. ...

Carol, thank you, and I understand now about the pickles. So it's the ph in pickling, or water bath canning tomatoes, that matters (which is why you can't just dump a bunch of bell peppers etc in your tomatoes, right?).

Can you explain to me, so I understand the "why" of the chemistry (in layman's terms), why the jams and jellies are ok with the alternative sweetener with the Pomonas? Because I thought it was the sugar that did the preserving - or are the regular recipes exact because of the exact amount of sugar to regular pectin, and it is actually the hot water bath canning that is doing the preserving??

Thanks!

In jams it is the fruit that will give the necessary acid to can it without sugar. That, and along with proper processing. That seals the jars with a true vacuum and kills bacteria, etc.
True, sugar does preserve, but in concentrations of approx. 50 percent or more.
That is why the shelf life in the fridge of Splenda, stevia, or other low/no sugar jams only last a short time before they mold.
You will find a few no sugar needed pickle recipes in the link below.
They use the kind that measures cup per cup being equal.

Here is a link that might be useful: Pickles for special diets.

Well, pH is one of the issues. Density and available water (moisture content) also play a role. That's why squash puree is no longer recommended for canning (density), why pickled beet slices should be packed loosely and not stacked like planks in the jar (density again) and why you can add dried peppers safely to pickles (no moisture issues) when you may not be able to add fresh ones.

Pickles and Pomona in jams are apples and oranges. Pickles are low-acid products - cucumbers, peppers, green beans, cauliflower, etc. etc. So adding acidity to lower pH and making sure processing time assures complete heat penetration are both critical.

Pomona is used with fruit spreads. (Technically they're not jams if they lack sugar.) Pomona jells the product, but if there isn't sugar or the level of sugar is very low, the spread will lack the natural keeping qualities of a traditional preserve with sugar. Hypothetically, a traditional full-sugar preserve could be jarred and put on the shelf without heat processing and there'd be minimal risk. It might mold or oxidize, but the sugar binds up the available water (osmotic effect) and the fruit is acid, so there really isn't much to worry about in terms of food safety.

Fruit spreads made with Pomona Pectin will jell and can be heat-processed, but once the jar is opened the refrigerator life is quite short because the preservative effect of sugar isn't there. Sugar does have its uses.

Carol

The above explaination is why I add extra acid to my jams. A no sugar blueberry I made last year was opened and in my fridge now, and ended up way in the back, over 8 months ago. No signs of any mold there yet. Pomona has a slightly different spreading, like a thicker 'jello' texture, compared to most commercial jellies. I also use a bit of honey in mine, but not enough to give it much sweetness, only a little 'stickyness'. Splenda comes in two forms. The big bags that have the 'puffed up' product that measures cup for cup as sugar, and the small paper packets that are much more concentrated. I will use the latter sometimes, as it doesn't give off any foam. The bagged puffed up version will create a LOT of FOAM when it starts to dissolve in simmering jellies and jams, thats not a good thing!!

I am a newbie when it comes to canning. My mother and I were canning several different items and pickled beets were one of them. Neither of us can remember if we put the sugar in the pickling solution. (we should've limited our projects) They were already processed and cooled before we thought about it. What will happen? Can sugar be added when heating them before serving? Or will omitting sugar cause the beets to spoil? I feel so stupid, but I am hoping all our work was not wasted. Anyone have any ideas?

If the beets were pickled in a vinegar brine (more than a 50% vinegar!), they should be fine. I usually like to taste a brine of any kind prior to adding it to the jars of things being pickled. Sugar in that amount is used to reduce the acid 'taste', but not its strength and effectiveness. You can add the sugar if you heat them up and cook them a couple of minutes before serving. Also, crack open a single jar, add some sugar to taste (mix until dissolved) and cover it again, then place it in the frisdge for maybe a day or two. It will not penetrate the beets much, but the brine will be sweeter. I like using a sweet mixed pickle brine similar to the type for cukes, cauliflour, and small onions. I use Splenda in my sweet pickle batches.

Assuming the brine was sufficiently strong (follows current standards for beets) as Ken mentioned, you should be fine safety-wise.

However, sugar preserves texture and increases shelf life and keeping qualities once opened, so unless your beets are consumed reasonably quickly, you may discover they're softer and don't hold as long in the refrigerator.

Carol