UC Master Food Preserver Program
University of California
UC Master Food Preserver Program

Citrus: Preserve it now to serve it safely later

Sue Mosbacher prepares fruit for canning.

Update: 2020 classes will be held as follows. For more information and registration, click here for a calendar and scroll down to the preferred class.





January 15



UCCE Solano County Meeting Room 501 Texas Street. Fairfield,

January 16



UCCE Napa County, 1710 Soscol Avenue, Suite 4, Napa

January 21



Chico Masonic Family Center, 1110 W. East Avenue, Chico

January 22

Yuba City


UCCE Yuba/Sutter County Conference room 142A Garden Highway, Yuba City

January 23

Grass Valley


Grass Valley Veterans Building 255 South Auburn, Grass Valley

February 5



The Green Church, 2108 Russell Street, Berkeley

February 6



Contra Costa Farm Bureau
5554 Clayton Rd # 4, Concord

Winter is the time when many backyard citrus trees and roadside fruit stands are laden with mandarins, lemons, navel oranges and limes. A UC Cooperative Extension expert is traveling the state to teach how the fresh taste of citrus can be preserved for year-round enjoyment.

UC Cooperative Extension Master Food Preserver coordinator Sue Mosbacher recently taught a roomful of attentive Mariposa County residents how to safely make marmalade jam, preserve lemons in salt to add flavor to savory dishes, and can grapefruit and orange sections with a little sugar to produce a fresh-tasting citrus cocktail high in vitamin C.

Mosbacher is a community education specialist based in El Dorado and Sacramento counties. But she has been driving up and down Highway 99 to bring research-based food preservation lessons to residents as far south as Madera County as part of a special project that was funded with a $140,000 grant from the U.S. Department of Agriculture's (USDA) Agricultural Marketing Service. (Through grant AM170100XXXXG011. The project's contents are solely the responsibility of the authors and do not necessarily represent the official views of the USDA.) 

Mosbacher has made dozens of appearances at county fairs and community meetings.

“It's been fabulous,” Mosbacher said. “People want the information and are using what they are learning.”

The series began last year with lessons focused on preserving summer fruit. The citrus classes are being offered in the winter. And in late spring 2019, Mosbacher will be on the road again to teach more fruit preservation classes and, in summer and fall of 2019, she will offer vegetable preservation lessons. The project is slated to conclude in 2020.

Master Food Preserver Barbara Mattice, left, helped Mosbacher demonstrate citrus preservation in class.

Mosbacher said she is energized for this journey by knowing that she is making a difference in California communities. She shared a telling story from a Georgetown vegetable preservation class. A participant said she had canned peas using the boiling water method; the Master Food Preserver Program guidelines require the use of a pressure canner for low-acid vegetables to prevent the growth of bacteria that produce the botulism toxin.

“She said she always canned peas in a water bath, and no one had ever died. But she came back the next week and told us she decided not to risk it and to throw the veggies to her chickens,” Mosbacher said. “And the next day, half her chickens died.”

Mosbacher has a background in computer science and the financial industry. During the 2008 downturn, she was laid off and spent time as a 4-H volunteer in the UC Cooperative Extension Office. While there, she learned about a part-time job opportunity working with UC Master Gardeners and UC Master Food Preservers.

At the time, she had no food preservation experience, so she took Master Food Preserver training.

“I learned everything I know from our own Master Food Preservers,” Mosbacher said.

Most citrus fruit is ready for harvest in the winter. It can be preserved a variety of ways to enjoy it year round.

Master Food Preservers are volunteer food preservation enthusiasts who have been trained in research-based preservation methods. Every food preserver training begins with a food safety primer with proven methods to decontaminate kitchen surfaces and tools, detoxify canned low-acid food and guard against spoilage.

At the citrus training, Mosbacher demonstrated canning a delicious orange jelly spiced with cinnamon, allspice and cloves. After cooking the juice with sugar and pectin, she canned the jelly using the boiling water method and with a steam canner. Either option is okay with high-acid citrus fruit.

Options for preserving lemons abounded. The juice can be frozen in an egg carton or ice cube tray, and used throughout the year in salad dressings, fruit salads, soups and ice cream. Slices of lemon can be dried to flavor ice water, seafood and casseroles. Mosbacher demonstrated preserving lemon wedges in salt water seasoned with bay leaves, cinnamon sticks and whole black peppercorns. She provided a recipe for a gourmet chicken tagine and roasted fingerling potatoes with preserved lemons to give participants guidance for using their preserved fruit.

At all the classes, participants are surveyed at the beginning and end to document the impact of the training. The preliminary results calculated with responses from 75 participants reflect positive results. After the class, nearly half of participants intended to preserve more fruit at home than they previously preserved. Two-thirds of participants intended to dehydrate more fruit than before. 

"The results are great," said Katie Johnson, UC Cooperative Extension nutrition, family and consumer sciences advisor in the Central Sierra. "We never see results this high with regard to health behaviors, so I think it's pretty exciting."

To learn about food preservation programs around the state and search for classes, visit the UC Master Food Preserver website. 

Canned wedges of grapefruit and oranges.


Lemon zest and coarse salt can be combined to make a long-lasting seasoning for fish, salads and other foods.
Class participants tasted spiced orange jelly, lemon curd and orange marmalade.
Citrus may be canned in many ways, include jellies and marmalades, pickled and candied.
Posted on Wednesday, April 10, 2019 at 8:46 AM


Where can I find the book in the photo above, Citrus: Preserve it, Serve it to buy a copy? I would love to do more with my citrus too.  
thank you for sharing! Jeanine

Posted by Jeanine Holmlund on February 12, 2019 at 7:33 AM

Thank you to Sue Mosbacher for sharing her food preservation expertise along the Central Valley in a delicious way!

Posted by Katie Panarella on February 14, 2019 at 10:33 PM

I think I may have broken a world record or at least a Placer County record. I took your "Citrus: Preserve It, Serve It" class in Auburn on 1/25/19 and it was love at first sight!  
I have a 5 year old dwarf meyer lemon tree in a pot that produced over 100 lemons this year. I saw your class advertised and being a novice canner and in need of a way to use up all those lemons, I was looking forward to the class. This is also the time of year for abundant local citrus crops like cara cara and blood oranges.  
I spent the rainy/snowy days of early February practicing what I learned in your class. Following is the success story of what I have learned. I have canned over 50 jars of jelly including citrus marmalade, lemon curd, meyer lemon thyme, lemon habanero, lemon lavender, honey lemon, and citrus spice jellies! I dried all the zest and made lemon sugar, lemon pepper salt, and have dried orange and lemon zest for baking!  
So far we have had the jelly on french toast and baked chicken and I even baked a citrus marmalade bundt cake! I knew your class was meant for me and I want to thank you for teaching me the safe and accurate way of canning. I look forward to taking even more classes through Master Food Preserver.  
Thanks again,  
Eileen Johnson

Posted by Eileen Johnson on February 22, 2019 at 3:41 PM

I’ll be using these recipes and passing them off to family and friends. Thank you!

Posted by Wendy Ford on March 2, 2019 at 7:13 AM

I have several citrus trees and I have left the fruit on them for way too long. How can I tell if the fruit is still fresh? I am very excited to try these techniques!

Posted by Sandra Jaenicke on March 10, 2019 at 3:05 PM

Sandra - The California Backyard Orchard website has great info on citrus trees and harvesting: http://homeorchard.ucanr.edu/Fruits_&_Nuts/. Another good resource is the UC ANR Publication #8199, Oranges. It has harvest and preserving information. Find it at https://anrcatalog.ucanr.edu/Details.aspx?itemNo=8199.

Posted by Sue Mosbacher on March 18, 2019 at 6:42 PM

Jeanine - we created the Citrus: Preserve It, Serve It booklet for the class. It's a combination of various University publications,  
local handouts, and meal ideas. Please contact our El Dorado County office to make arrangements for a copy. 530-621-5502 or cecentralsierra@ucanr.edu. I'm sure you'll enjoy it.

Posted by Sue Mosbacher on March 18, 2019 at 6:47 PM

Thank you, Sue, for getting the word out. You are one of my mentor heroes!

Posted by Vivian Patterson on April 11, 2019 at 1:50 PM

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