Sugar’s role in home canning

Summary

There are two aspects to the word “preserving.”

1. Food safety, to avoid food poisoning;
2. Preserving the “appeal” of the food: the quality of the food in terms of texture, colour, taste,and  appearance.

In the quantities used in home canning, sugar has texture and colour preserving properties, but not food-safety preserving properties.

Sweetness plays a role not just in jams, jellies and fruits: it also plays a flavour role in savoury items such relishes and pickles. Sweetener helps to make the food product more palatable by masking the tartness and sourness of the acidity. Without sweetness, some pickled products might just be inedible to many people’s tastes.

Linda Ziedrich, author of the Joy of Pickling, says,

as Extension agents explain, the purpose of the sugar in such recipes isn’t to ensure safety but to balance the sharpness of the vinegar.” ^[1]Ziedrich, Linda. Gardener’s Table blog. “Rice vinegar for home canning.” 2 June 2012. https://agardenerstable.com/2012/06/02/rice-vinegar-for-home-canning/

Sugar, as a carbohydrate, can also act as a thickener, binding up free water.

Some recipes claiming to be sugar free are in fact merely free sugar in its refined white form. They will swap in other forms of free sugars such as honey, maple syrup or agave nectar. Such recipes are not helpful for diabetics, people with sugar sensitivity, or people wanting to lose or manage their weight.

Sugar’s role in safety

The experts say that sugar does not always play a safety role in home canning. (Note: there are a few recipes where it does.)

Barb Ingham at Wisconsin Extension says, “You can omit or reduce the sugar when freezing fruits, and when making pickles, salsas and sauces”   ^[2] Ingham, Barb. Safe Preserving: Using Splenda. University of Wisconsin Cooperative Extension. 9 September 2013. Accessed March 2013 at https://fyi.uwex.edu/safepreserving/2013/09/09/safe-preserving-using-splenda/

Michigan State University Extension says, “All fruits can be safely canned or frozen without sugar… Sugar is not needed to prevent spoilage and that is why water or fruit juice can be substituted for sugarless home-canning. If you are on a special diet or are just watching your calories you may want to try canning without sugar; it is a good option.”  ^[3] Nichols, Jeannie. Home canning without sugar. Michigan State University Extension. 14 August 2012.

Utah State Cooperative Extension says, “Sugar helps fruit retain a bright color and firm texture, but is not necessary for safety.”  ^[4] Riggs, Kathleen. Avoiding Common (Major and Minor) Canning Mistakes. Utah State Cooperative Extension. March 2009. FN/Food Preservation/2009-01. https://extension.usu.edu/files/publications/publication/FN_Food_Preservation_2009-01.pdf

Angela Fraser at Clemson University says, “Canning fruits and vegetables without adding sugar or salt does not affect the processing time or the safety of the product.”  ^[5] Fraser, Angela. Associate Professor/Food Safety Education Specialist. How Canning Preserves Food. Clemson University, Clemson, SC. Accessed March 2015 at https://www.foodsafetysite.com/consumers/resources/canning.html

Virginia Cooperative Extension says, “Sugar is primarily added to improve flavor, help stabilize color, and retain the shape of the fruit. Fruits canned without sugar will be softer in texture than those canned with sugar.”  ^[6]  Boyer, Renee R. Boiling Water Bath Canning. Virginia Cooperative Extension. Publication 348-594. 2013. Accessed March 2015 at https://pubs.ext.vt.edu/348/348-594/348-594_pdf.pdf Page 3.https://pubs.ext.vt.edu/348/348-594/348-594_pdf.pdf

Brent Fountain at Mississippi State University Extension Service says, “Q: Is it safe to can without salt and sugar? A. Salt and sugar are not necessary for safe processing of fruits and vegetable.”  ^[7] Fountain, Brent. Home Canning: Questions and Answers. Mississippi State University Extension Service. Publication 99. Accessed March 2015 at https://msucares.com/pubs/publications/p0993.pdf

The National Center for Home Food Preservation (NCHFP) says, “Sugar is not needed for safety because the heat used in canning is what kills microorganism and preserves the product.”  ^[8]  National Center for Home Food Preservation Self Study Course. Module 3. Canning Acid Foods:  Canning Liquids for Fruits. Accessed March 2015. [Ed:  Here they are discussing canning low-acid products. pH is as important as heat when it comes to water-bathed or steam-canned products.]

Note that it is possible to affect the safety of a home-canned good by using too much sugar. Sugar is, after all, a carbohydrate, and carbs impact the density of foods. Elizabeth Andress, head of the NCHFP says, “The following slow down heat penetration: – Extra sugar or fat.” ^[9]Andress, E.L.  2008. Pressure canning & canning low-acid foods at home (slides). Athens, GA: The University of Georgia, Cooperative Extension.. Accessed August 2016

Sugar’s role in quality

Even though sugar has no impact one way or the other on the aspect of food safety, it can often play a role in preserving texture and colour.

“The texture and color preserving aspects of a sugar syrup will not be provided.  The result would be like canning in water …..  The USDA fruit canning directions do allow for canning in water (i.e., without a sugar syrup), as there is adequate preservation for safety from the heat of proper canning.”  ^[10] National Center for Home Food Preservation: Can Splenda® (sucralose) be used in preserving food? In: Frequently Asked General Preservation Questions. Accessed March 2015 at https://nchfp.uga.edu/questions/FAQ_general.html#3

For some recipes that call for extremely heavy amounts of sugar, if you are going to get the same time length of shelf stability, the water bath processing times seem to require 5 to 10 minutes added onto them:

“…for shelf stability…..Sugar is required for the preservation of these syrupy fruit preserves as published, with very short boiling water canner processes.  Without that heavy amount of sugar, these products become fruit pieces canned in water or lighter sugar syrups, and the usual (and longer) fruit canning process times and preparation directions would need to be used.”   ^[11] National Center for Home Food Preservation: Can Splenda® (sucralose) be used in preserving food? In: Frequently Asked General Preservation Questions. Accessed March 2015 at https://nchfp.uga.edu/questions/FAQ_general.html#3

Note that the above advice relates to long-term shelf quality, rather than a safety issue. But then again, the USDA also now advises us not to store for more than a year anyway.

Georgia Lauritzen at Utah State says,

Sweeteners are considered an essential ingredient of most of the products of the canning industry, except vegetables. They act as preservatives and maintain desirable appearance, flavor, color and body in the products. Altering the type and amount of sugar in standardized preservation recipes will alter these characteristics. The principal sweeteners used in canning are sugar (sucrose), and corn syrup……

The addition of sugar to canned fruit aids in retaining the shape, texture, color, appearance, and flavor of the original product. When sugar is not used or reduced in canning, there will be slight changes in these characteristics. When canning fruit without the addition of sugar, or at reduced levels, follow the tested directions for the product being preserved.”  ^[12] Lauritzen, Georgia C. Reduced Sugar and Sugar-free Food Preservation. Utah State University Cooperative Extension.  FN209. 1992. Accessed March 2015 at https://extension.usu.edu/files/publications/publication/FN_209.pdf 

William Schafer with the University of Minnesota Extension Service wrote,

The high cost of commercially canned, special diet food often prompts interest in preparing these products at home. Some low-sugar and low-salt foods may be easily and safely canned at home. However, the color, flavor, and texture of these foods may be different than expected and be less acceptable.” ^[13] William Schafer. Canning Basics 10: Canning Foods for Special Diets. University of Minnesota Extension Service. 2010. Accessed January 2015 at https://www.extension.umn.edu/food/food-safety/preserving/canning/canning-basics-10/

The following advice is from an extension agent in Mississippi. He doesn’t want you to reduce sugar in recipes, but he does clarify that his concern relates to quality, not safety:

Q: Is it safe to can without salt and sugar? A. The salt in recipes for pickled products and sugar in jams, preserves, and jellies should not be reduced, since the measures given are needed to provide good quality.”  ^[14] Fountain, Brent. Home Canning: Questions and Answers. Mississippi State University Extension Service. Publication 99. Accessed March 2015 at https://msucares.com/pubs/publications/p0993.pdf

Patricia Kendall, Professor and Extension Specialist at Colorado State University, essentially says you can try sugar-free relish and pickle recipes, but says that (in her experience) the quality can be uneven:

Sweet relish and pickle recipes do not adapt as well to sugar-free canning as do plain fruits. Try recipes that call for artificial sweeteners, but don’t be too discouraged if some batches are disappointing. Finished products often are mushy or have an unsuitable flavor. When canning pickles and relishes, use the boiling water bath method and processing times that are adjusted for altitude.”  ^[15] Kendall, P. Canning Fruits. Colarado State University Extension. No. 9.347. June 2013. Accessed March 2015 at https://www.ext.colostate.edu/pubs/foodnut/09347.html

But finally, some practical wartime advice from a time when backing up a dump truck full of sugar and emptying it into your preserves was simply not an option, owing to rationing:

Sugar customarily used in canning fruits does improve their texture, flavor and color, but it does not prevent age, according to Mrs. Madge Little, of the home economics extension staff, University of Illinois College of Agriculture. When sugar is scarce, appearance and flavor take second place. Saving the fruit is the important thing, and this can be done with little or no sugar, provided the proper methods of sterilization are followed and a perfect seal is accomplished.”  ^[16] SUGAR ALLOWANCE SHOULD BE USED WISELY IN CANNING. Farmers’ Weekly Review, 30 June 1943. Joliet, Illinois. Page 1.

Old fears about sugar substitutes in canning

Experts were opposed to sugar substitutes in home canning because of quality issues.  HealthyCanning.com feels that this general advice is now dated — it dates from testing almost a generation ago, when what they had to test was saccharin or aspartame based, and modern alternatives such as sucralose and stevia were only just coming on the market.

In the interest of thoroughness, however, it’s important to acknowledge that concern and bring it forward.

We’ve seen the concern expressed as early as 1942 by the USDA:

Housewives often ask about using saccharine instead, of sugar in canning and preserving. Saccharine is not a food but a coal-tar product with an extremely sweet flavor, often used in diabetic diets. You can’t use saccharine in canning because heating makes it bitter.” ^[17]USDA Homemakers Chat. Stretching your sugar in canning. 17 April 1942. Page 3.

The University of Missouri Extension recorded this advice back in 1989 from Dr Gerald Kuhn: “While both Equal (aspartame) and saccharin-based sweeteners are safe to use, the quality of any pickled product made with either of these sweeteners is poor. Equal quickly loses its sweetness when heated while saccharin-based sweeteners become bitter.” Source: Personal communication with Dr. Gerald Kuhn, Food Scientist, Penn State University, June 1989.  ^[18]Accessed August 2017 at https://missourifamilies.org/quick/foodsafetyqa/qafs556.htm

Kuhn may have been the last one who actually had the resources to test sweeteners, back in the 1980s, using what was on the market back then. At that time, North Americans had only just discovered olive oil and hadn’t discovered kale yet.

Since then as far as we’re aware, there’s not been resources for much if any testing, and the advice from that era is just repeated.

Colorado State University Extension says, “Saccharin-based sweeteners can turn bitter during processing. Aspartame-based sweeteners lose their sweetening power during processing.”  ^[19] Kendall, Pat. Canning Fruits. Colorado State University Extension. No. 9.347. June 2013. Accessed March 2015 at https://www.ext.colostate.edu/pubs/foodnut/09347.html

University of Wisconsin-Extension says, “Sugar substitutes (artificial sweeteners) are not recommended in pickling because the heat processing required may cause a bitter flavor.”  ^[20] Ingham, Barbara H. Homemade Pickles & Relishes. Wisconsin Safe Food Preservation Series. University of Wisconsin-Extension Cooperative Extension. B2267. 2008. Accessed March 2015 at https://learningstore.uwex.edu/assets/pdfs/B2267.PDF Page 8

Penn State says, “In general, non-nutritive (artificial) sweeteners are not recommended for canning. Aspartame containing sweeteners such as Equal or NutraSweet degrade with heat and lose their sweetening power. Saccharine-based sweeteners such as Sweet’N Low, Sugar Twin, or Sweet 10 become bitter when exposed to canning temperatures and should be added after the canned fruit is opened. Sucralose or Splenda is a new artificial sweetener derived from sugar molecules and will not produce an aftertaste when heated.”  ^[21] Penn State Extension.  Canning With Artificial Sweeteners . Accessed January 2015 at https://extension.psu.edu/food/preservation/faq/canning-with-artificial-sweeteners

Michigan State says, “You may want to stay away from using saccharin- and aspartame-based sweeteners when canning. Saccharin-based sweeteners turn bitter when processed. Aspartame-based sweeteners lose their sweetening power during processing. ”  ^[22] Nichols, Jeannie. Home canning without sugar. Michigan State University Extension. 14 August 2012.

Ball says, “For best results, add non-sugar sweetener just before serving canned fruit.”  ^[23] Fresh Preserving & Canning Questions. Ball Web site.  Accessed March 2015 at https://www.freshpreserving.com/tools/faqs

The National Center says, “Saccharin or aspartame-based artificial sweeteners in canned fruits are best added just before serving.  Sucralose (e.g., Splenda) is a newer sugar substitute that can be added prior to canning.”    ^[24]  National Center for Home Food Preservation Self Study Course. Module 3. Canning Acid Foods:  Canning Liquids for Fruits. Accessed March 2015.

Summary of sugar concerns to be addressed

We have now seen that:

1. There is no food safety concern about sugar-free home canning;
2. There are concerns about sugar-free products not being as high quality in terms of long-lasting texture and colour; and
3. There are concerns that some sugar substitutes are to be avoided because they don’t perform well in canning. Those sweeteners were, to be precise, saccharin or aspartame based.

Let’s try therefore now to address points (2) and (3).

Compensating for lack of sugar in sugar-free home canned products

Sweetness

Even for those who may say they don’t necessarily have a sweet tooth, sweetness is often necessary in some pickled items, even, in order to take the edge off from the harsh, white vinegar used in canning.

HealthyCanning.com uses both Splenda and stevia as non-caloric sweeteners. When it comes to stevia, we use liquid stevia for purity of taste, ease of use, and for the quality results it delivers in home canning.

Firming and crisping

“Sugar helps to firm the vegetables in a relish.”  ^[25] Penn State Extension. Relishes.  September 26 2012. Accessed January 2015 at https://extension.psu.edu/food/preservation/news/2012/relishes

Sugar can help in achieving and maintaining a firmer texture in fruits and vegetables. To compensate, we could simply use a few pinches of Pickle Crisp ® (aka calcium chloride) per jar.

Really, though, the crispness of your pickle is going to absolutely depend on how long it was since your cucumbers were picked, and once they lose that crisp snap, nothing you can add to the jar — not sugar, not Pickle Crisp, not grape leaves — can restore it.

Colour

Sugar can help the colour of some foods to stay sharper for longer. Ascorbic acid, citric acid and Vitamin C are other elements that can help improve the staying power of colour.

Utah State University Cooperative Extension says, “Noncaloric sweeteners do not help retain color or texture in home preserved fruits. The use of an antioxidant such as ascorbic acid will result in better color when no sugar is used.”  ^[26] Lauritzen, Georgia C. Reduced Sugar and Sugar-free Food Preservation. Utah State University Cooperative Extension.  FN209. 1992. Accessed March 2015 at https://extension.usu.edu/files/publications/publication/FN_209.pdf

Colorado State University Extension says, “If ascorbic acid products are not used in the pretreatment of cut fruit, they may be added to the canning juices or liquids before processing. This will help keep the fruit from darkening during storage. Use ¼ to ½ teaspoon crystalline ascorbic acid or 750 to 1,500 mg crushed vitamin C tablets per quart of fruit. Commercial ascorbic and citric acid mixtures also may be used according to manufacturer’s directions.”  ^[27] Kendall, P. Canning Fruits. Colorado State University Extension. No. 9.347. June 2013. Accessed March 2015 at https://www.ext.colostate.edu/pubs/foodnut/09347.html

Consistency

Sugar can act as a thickener to provide body. In recipes using no sugar needed pectins, the pectin takes care of the body. Other than that, HealthyCanning.com hasn’t yet found a need to compensate directly on the “body” issue in any of the recipes posted on the site.

Penn State Extension says, “Most pickles and relishes and jams and jellies still need sugar for the proper consistency, but a few new recipes have been developed for low or no sugar products.”  ^[28] Penn State Extension. Canning with Less Sugar .  17 September 2012. Accessed January 2015 at https://extension.psu.edu/food/preservation/news/2012/canning-with-less-sugar

They go on to say: “You can use Splenda® and other non-heat sensitive artificial sweeteners in jam or jelly made with no-sugar needed pectin. Package inserts with commercial pectins tell you when you should add artificial sweeteners. Artificial sweeteners do not provide the properties of sugar needed to jell traditional long cook jams and jellies though.”  ^[29] Penn State Extension. Canning with Less Sugar .  17 September 2012. Accessed January 2015 at https://extension.psu.edu/food/preservation/news/2012/canning-with-less-sugar

Processing times

In general, the presence or absence of sugar does not influence processing times one way or the other.

“Canning fruits and vegetables without adding sugar … does not affect the processing time.”  ^[30] Fraser, Angela. Associate Professor/Food Safety Education Specialist. How Canning Preserves Food. Clemson University, Clemson, SC. Accessed March 2015 at https://www.foodsafetysite.com/consumers/resources/canning.html

That being said, the National Center for Home Food Preservation advises that a few recipes on its site (fig, peach and pear fruit preserves in thick sugar syrup) would require the longer normal canning times for those fruits if sugar is left out:

“Splenda® cannot be used in several traditional Southern preserves we have on this website or in the University of Georgia Extension publications. These are whole or uniform pieces of fruit in a very thick sugar syrup, usually made with figs, peaches or pears. (These preserves are not jam or pectin gel products.) Sugar is required for the preservation of these syrupy fruit preserves as published, with very short boiling water canner processes. Without that heavy amount of sugar, these products become fruit pieces canned in water or lighter sugar syrups, and the usual (and longer) fruit canning process times and preparation directions would need to be used.”  ^[31] National Center for Home Food Preservation. Can Splenda® (sucralose) be used in preserving food? Accessed June 2015 at https://nchfp.uga.edu/questions/FAQ_general.html

What are the results of sugar-free canning like?

Some of the home canning experts are really down on the idea; and you get the impression that they just wish the whole topic would go away.

They say, as you’ve seen, that while there is no safety concern, that the quality is not desirable.

Here at HealthyCanning.com, our findings have been the exact polar opposite, and we consequently have to respectfully but firmly disagree.

We’ve had absolutely fantastic results in terms of quality and taste — using the canning experts’ own tested, quality recipes.

Further reading

Splenda. National Center for Home Food Preservation: Can Splenda® (sucralose) be used in preserving food? In: Frequently Asked General Preservation Questions.

Lauritzen, Georgia C. Reduced Sugar and Sugar-free Food Preservation. Utah State University Cooperative Extension.  FN209. 1992.

Slemmer, John. How to Make a Sugar (or non-sugar sweetener) Solution for Homemade Canned Fruits.