SERIES: Safe Jams & Jellies

Posted 5.12.2021

SAFE JAMS & JELLIES: Reducing Sugar 

I love it when posts prompt comments and questions that spur me to research and share information. When  I shared the image of the proportion of ingredients in a jar of Nutella it stirred up a lot of interest (spoiler alert, it is about half sugar).  A shout out to 

I was able to pull together some research from the Ball site, Pomona’s Pectin, and the National Center for Home Preservation. I didn’t make a picture but the chart below is pretty revealing. There is an awful lot of sugar in most jellies and jams.

I know that there are several ways to make low sugar jams, and I’ve  been making them for years. I was surprised to see a debate online about whether it “is safe to reduce the proportion of sugar to fruits?”  After digging deeper I found the short answer is (wait for it)......, “It depends on which method you use.”  

Jams and jellies can be a great way to store berries for the winter but should be as healthy as possible. In upcoming posts we’ll be exploring what makes a jam or jelly gel, pros and cons of different methods, and finally some canning techniques that Grandma used that are no longer considered safe but still show up online. 

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Posted 5.19.2021

SAFE JAMS & JELLIES: Are Low Sugar Jams and Jellies Safe? - Part 1

I love to do research, so when faced with the internet debate, “In jams, is it safe to reduce the proportion of sugar to fruits?” I went  back to school (well reliable sources on the Internet) and refreshed myself on the science.  I found the short answer, and the only answer, is:......, “It depends on which method you use.”

 The secret of what makes jams and jellies (preserves) shelf stable is removing harmful microorganisms and keeping them from growing back. Heating of the mixture in the process of making and canning is the main way to remove bacteria and molds, but there are several factors involved in keeping a  product safe.

 Temperature:  When you preserve something in a boiling water bath canner, you heat the jars and their contents in water that covers the jars at a full boil for a specific length of time according to a trusted source like Ball canning.  The time is specific to the recipe and size of jars which is enough to kill off the micro-organisms and seal the jars.  Anything that is preserved in a boiling water bath must have a high acid content like jams & pickles...

 Acidity:  Botulism spores can only develop and release the botulism toxin in a low acid, oxygen-free environment. The way food scientists (and home canners) determine whether something is high or low in acid is by pH. If something has a pH of 4.6 or higher, it is deemed high in acid and is safe for boiling water bath canning.  All berries and fruits, with the exception of figs, are acid foods.

 Active Water: Bacteria need available water to grow. Reduction of water activity in foods prevents the growth of bacteria and toxin production by molds and bacteria.  Heating, freezing, dehydrating, and using pectin to gel products are all ways to reduce water activity in foods.

 So how does all this relate to making jam and what sugar has to do with it?

 Pectin makes the magic of preserves

 In nature Pectin is a carbohydrate found mostly in the skin and core of raw fruit. It functions as the "cement" that helps hold cell walls together. In solution, pectin has the ability to form a mesh that traps liquid, sets as it cools, and, in the case of jam, suspended pieces of fruit. Regular Pectin needs partners to work properly, namely acid and an activating agent like sugar or in some pectins, calcium salts.  More about these pectins later.

 Sugar enhances the strength of the gel by attracting some of the water away from the pectin. In the absence of sufficient water, pectin molecules are more likely to unite with each other. Sugar also acts as a preservative, firms the structure of the fruit, and helps the jam or jelly hold its color and flavor.

 Remember that each jam or jelly recipe is designed to maintain the proper balance of pectin, fruit, and sugar... more coming in Part 2  of  this question, later this week!

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Posted 5.21.2021

SAFE JAMS & JELLIES: Are Low Sugar Jams and Jellies Safe? - Part 2

Where we left off . . . 

Sugar enhances the strength of the gel by attracting some of the water away from the pectin. In the absence of sufficient water, pectin molecules are more likely to unite with each other. Sugar also acts as a preservative, firms the structure of the fruit, and helps the jam or jelly hold its color and flavor.

 Remember that each jam or jelly recipe is designed to maintain the proper balance of pectin, fruit, and sugar.

Three ways to make jam:

1. Using the natural pectin found in some fruits
2. Using traditional, high-methoxyl pectin
3. Using a low-methoxyl pectin like Pomona’s Universal Pectin.

Comparing Methods

No Pectin Added method relies on the pectin in the fruit or mixing a high pectin fruit with a lower one, time, and A LOT OF SUGAR.  It needs to cook long enough for some of the moisture to evaporate and the sugar draws out the pectin and combines. As an example we’ve posted  a Cranberry- Blueberry Jam (https://foodinjars.com/recipe/cranberry-blueberry-jam/) recipe that has only three ingredients: Blueberries, Cranberries, and lots of sugar.  You may have noticed that the chart on pectin in fruit says that blueberries always requires additional pectin or acid, but the cranberries provide both in this recipe.

The recipe requires at least 25 minutes of cooking. LearntoPreserve.com suggests 3 ways to know when it is ready to can.

1. Use a candy thermometer.  Boil until mixture reaches 8 degrees above the boiling point of water. Sea level is = 220 ℉

2. Use a spoon, also called the “sheeting test”: Dip a cool metal spoon into the boiling jelly mixture. Raise the spoon out of the steam and turn it so the liquid runs off the side. forms a sheet that hangs off the edge of the spoon as seen in this drawing.

3. Use a chilled saucer. Place 2 or 3 saucers in the freezer. Spoon a teaspoon of the hot jam onto a cold saucer and let it rest for 30 seconds. Push your fingertip into the jelly, and if it wrinkles, it's ready!  (If you need to test again, you should still have 1 or 2 more cold saucers in the freezer.)

Traditional Pectin method uses a (High-methoxyl  pectin) pectin usually made from apples.  It always requires added sugar to do its thing.   There are many sources that give recipes that help you maintain the right proportions.  Please see the resources list. Below is a link to a Traditional Strawberry Jam recipe from Ball https://www.freshpreservinguk.co.uk/recipes/strawberry-jam 

Knowing when the jam is ready is mostly based on time but if you want to be sure it’s ready to can,  do the sheeting or plate test after the sugar is fully dissolved.

Pomona’s Universal Pectin, (low-methoxyl  pectin)

While there are other brands of low-methoxyl pectin, Pomona’s  is specially formulated for making low sugar jam & jelly.  It is made from citrus peels and is activated by a calcium salt rather than sugar so it will work with any sweetener or no sweetener at all.  Calcium can be naturally present in fruits but it is hard to know how much is present so each Pomona's recipe  gives a recommended amount to add.  It is provided in the package with the pectin powder.  Below is a link to a recipe for Strawberry Jam using Pomona’s Pectin for comparison.   Notice that you mix the calcium powder to water and add it first and then mix the  pectin with the sweetener and add last.   I recommended the spoon or plate test after the sugar/pectin  mixture is dissolved. https://pomonapectin.com/project/strawberry-jam/

Pros & Cons of Each Method

No Added Pectin: High sugar, fuller fruit flavor, no chunks of fruit like in a marmalade, takes more cooking time.

Traditional,  high sugar content, recipes are exact proportions and are not easily increased or decreased.  Can be over cooked which kills gelling.

Pomona’s can have very low sugar or alternative sweetener. Highly reliable.  Some recipes give a slightly different color or texture than traditional

Shelf-life

There are a wide variety of opinions on shelf-life but most agree that if the jars remain properly sealed they are good on the shelf for least a year. Most of us keep them for 2 - 3 years.  Shelf Life Advice

Remember that if a jar has formed mold on the top just scraping it off doesn’t make it safe, molds send their roots deep and by the time you see the mold it has probably spread throughout the jar.   And mold can release toxins that affect many people.  

Resources

Recipes and Information:

National Center for Home Food Preservation https://nchfp.uga.edu/how/can7_jam_jelly.html

Ball Canning https://www.freshpreserving.com/recipes?fdid=Jams-Jellies-Marmalades 

 More Information on Gelling tests:

 Learn to Preserve  http://learntopreserve.com/gelling-point-tests/#:~:text

More Information on Low Sugar Products:

 MSU Extension https://www.canr.msu.edu/news/preserve_low_and_no-sugar_jams_and_jellies#:~:text

 Shelf Life Advice: http://shelflifeadvice.com/condiments-herbs-spices-spreads/spreads/jelly-jam-and-preserves#:~:text

Dangers of Mold on Jams and Jellies:

https://www.insider.com/can-you-eat-moldy-jam-jelly-is-it-safe-2020-7 

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Posted 5.26.2021

SAFE JAMS & JELLIES: Not Your Grandma's Jam 

“It's exciting to see the ah-ha moments when I explain and discuss the reasons behind the research-based preservation techniques UC Master Food Preservers teach. Just because grandma or mom did something and no one got sick, does not mean that the process is safe by today's standards.”

~ Sue Mosbacher, UC Master Food Preserver Coordinator

In the conclusion of our series on Safe Jam and Jelly Practices, we’re going to take a little side trip to  take a look at our Nanas’ long held traditional methods, and some modern ones, that are mostly unsafe.

Again quoting Ms. Mosbacher,  “The traditional methods of preserving jams and jellies was to cook the product, put it in a sterile jar, and either pour melted paraffin wax on top or put a lid on then turn the jar upside down to force a seal. Each method has its own set of food safety concerns”.

Paraffin Wax Method

The paraffin wax creates a fairly effective barrier between the jam  and the surrounding air, but only if  the product was stored in a consistently cool place.  That is one of the reasons having a root cellar was so important. But when temperatures fluctuate, the wax contracts with cold temperature, letting in pathogens, molds, and possibly insects. When temperatures rise, the wax will expand and fill the space again, sealing in the unsavory intruders beneath the wax.

Inversion or Open Kettle Method

Quoting Sue M’s article again, “Another common canning practice was to sterilize the jars, fill almost to the top with hot jam or jelly, put the lids on, and turn the jars upside down to force out the air and create a vacuum seal. …. This method made a more consistent barrier than wax, but there is still a common potential problem with the food inside the jar…."

1.      When we boil jam and jelly in a cooking pot, we still don't reach a high enough temperature to destroy all spoilage and food poisoning organisms. The cooking process in the open kettle isn’t enough to safely preserve food. In water bath canning the temperature inside the jars is raised significantly higher and held for a much longer time to ensure eliminating bacteria in the food.

2.      Plus, the air we trap in the jar with a lid is filled with floating microorganisms. When processed in a boiling water or atmospheric steam canner, there's enough of an increase in the temperature within the jar there is enough of a pressure increase to force air out of the jar. When we remove the jars from the canner, the pressure equalizes and the vacuum seal forms over pathogen-free food.

3.      Modern canning lids are not meant to seal in this way. Inversion canning creates a much weaker seal that can slowly give way over days, weeks, or months.

4.      Inversion canning doesn’t remove the air above the product and flipping it back and forth can trap there air and create air pocket where things can grow. (Side note, this method is also called, “Flipping the Jelly.”)

5.      Flipping the jars during the cooling process can cause the seal to fail.

6.      In the inversion method the jars themselves are not heat high enough for long enough to be sterilized

Importance of Sugar

As we discussed in the second part of this series, sugar can play an important role beyond making jams and jellies sweet. It held regular pectin to set forming a gel bind water so it is unavailable for bacteria and molds to grow.

If you want to make a low-sugar jam or jelly get a good recipe that is made to work with calcium instead of sugar so you will get a good gel.  And remember that low-sugar products won’t keep as long as high sugar ones, even in the refrigerator once they are opened. Several instructors I know recommend canning in the smaller 4-ounce jar if you use sweets slowly to make it easy to finish while it stays fresh.

Other Methods of Canning to Avoid

Steam Canning.

Not to be confused with modern Steam Canners which are designed for this purpose and have been thoroughly tested.  This method is just using a regulator steamer with a inch or so of water in the bottom and a loose fitting lid.

A wide variety make shift methods have been used in the past but only an approved model of Steam Canner should be used. Here is a link to a good article explaining details. https://anrcatalog.ucanr.edu/pdf/8573.pdf

Aspirin Preservation

It involves adding tablets of aspirin to low acid foods and then water bath canning them. This is rather than pressure canning them, as you would normally do with low acid foods.  It is not safe since it doesn’t add much acidity.  No experts seem to know how this myth got started. 

Oven Canning

First off, canning jars are not designed for that much dry heat and will break much of lf the time. Secondly, dry heat travels differently than steam of hot water and the food in the center of the jars may not get hot enough.

Instant Pot of Other Multi-Functional Pressure Cookers

Using an Instant Pot or other multi-cookers for can is not recommended by the National Center for Home Food Preservation,

"We do not know if proper thermal process development work has been done in order to justify the canning advice that is distributed with these pressure multi-cooker appliances. What we do know is that our canning processes are not recommended for use in electric pressure multi-cookers at this time."

https://nchfp.uga.edu/publications/nchfp/factsheets/electric_cookers.html#:~:text=What%20we%20do%20know%20is,1

For an explanation five other unsafe methods of canning like oven, microwave and solar, I refer folks to Michigan State University Extension's article "Downright Unsafe Canning Methods"

https://www.canr.msu.edu/news/downright_unsafe_canning_methods

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