How do I make fruit syrup, or turn a soft batch into one?

To make fruit syrup on purpose, cook strained berry juice with sugar from a tested syrup recipe, fill hot jars and process them in a boiling water canner; canned this way it keeps its best quality for about a year. To use a batch of jam or jelly that did not set, you have two honest choices: remake it to a set with USDA's procedure, or keep the sealed jars as they are and serve them as syrup. What you should not do is thin a soft jam with water and re-can it, because no one has tested that. This page covers both routes, with the numbers.

Which route fits your situation

Making berry syrup on purpose

Syrup is easier than jelly because you are not aiming for a gel. You still need juice, sugar in the tested proportion and a proper canning process, because a syrup has far more free water than a set jelly and the process is what makes it shelf stable.

Two tested versions are widely reproduced by extension services. They differ in proportion and in headspace, so keep each one's numbers together.

The blueberry syrup can also be processed in an atmospheric steam canner for the same time [1]. The WSU version allows a whole-fruit syrup by swapping 1 to 2 cups of the juice for the same amount of fresh or frozen fruit, keeping the 7 cups of sugar [2]. Its processing table did not survive in the online copy reviewed for this page, so use the printed publication or the blueberry syrup times if you make it.

Steps for the blueberry syrup

1. Make the juice. Select 4 cups of table-ripe blueberries (not underripe ones), wash them and remove any stems. Crush them, heat to a boil and simmer for 1 or 2 minutes. Strain through a colander and drain until cool enough to handle, then strain the collected juice through a double layer of cheesecloth or a jelly bag and discard the dry pulp. Expect about 2 1/2 cups of juice [1]; extracting juice for jelly covers the bag, the drip and how much juice to expect.
2. Cook. Combine 2 1/2 cups juice, 3 cups sugar, 1/2 cup corn syrup and 2 tablespoons lemon juice in a saucepan. Bring to a rolling boil and boil for 1 minute [1].
3. Skim. Remove from the heat and skim off the foam [1]. WSU adds that foam left in the jars can shorten the syrup's shelf life [2].
4. Fill. Pour into hot half-pint jars, leaving 1/4 inch headspace. Wipe the rims and adjust the lids [1].
5. Process for 10 minutes in a boiling water or atmospheric steam canner [1]. The same sheet's syrup table gives 10 minutes up to 1,000 feet, 15 minutes from 1,001 to 6,000 feet, or 20 minutes above 6,000 feet [1]. In Boise, that is 15 minutes.
6. Cool and check seals as you would for jam.

Corn syrup is often used in syrups to discourage sugar crystals. It is part of the tested recipe, so leave it in.

How long syrup keeps

Properly canned syrup stored in a cool, dry, dark place keeps high quality for at least a year; once opened, keep it in the refrigerator and use it within a month [2]. To freeze syrup instead of canning it, leave 1 inch of headspace for expansion; frozen syrup keeps high quality for a year [2]. If a canned jar does not seal, refrigerate it and use it, freeze it, or reprocess it within 24 hours using the original time, after checking the jar rim for nicks and changing the jar and lid if necessary. WSU's guidance is that a jar that comes unsealed after 24 hours must be thrown away [2].

Rescuing a soft batch

Before you decide anything, be sure the batch really is soft. Many jams and jellies take a day or two to firm up and some take longer, so do not open the jars or remake them on the first evening.

Option 1: remake it to a set

USDA publishes a remake procedure for soft jelly, which extension services apply to jam as well. It works per quart of soft product, by one of three routes (powdered pectin, liquid pectin, or bottled lemon juice alone), in batches of no more than 4 to 6 cups at a time, and the remade jars are filled hot with new lids and processed again [3]. The amounts for each route, the processing times for the remade jars and how to diagnose why the batch failed are on jam that didn't set.

Option 2: keep it as syrup

If the jars sealed after the recipe's full process, nothing about the food has changed except its texture. Leave the jars sealed, relabel them "syrup" or "pourable jam," and serve them over pancakes, yogurt or ice cream. This is the simplest rescue and costs nothing.

Things that take you outside the tested process:

• Opening the jars, thinning with water or juice, and canning again. That changes the sugar and water balance the recipe was tested at. Thin it as you serve it instead.
• Adding cornstarch or flour to thicken it. Penn State's guidance is that no starch, modified or regular, should be added to home-canned products unless a tested recipe calls for it [4].
• Moving it to bigger jars. The process was tested for the jars the recipe lists.

Once a jar is open, store it in the refrigerator like any opened jam.

Fruit sauces for the table

A fruit "sauce" is usually just syrup or soft jam warmed and loosened at serving time, with a squeeze of lemon, a splash of water or a spoon of liqueur. Make it in the amount you will use within a few days and keep it refrigerated. If you want a thick dessert sauce that sits on a shelf, look for a tested recipe for that exact sauce; thickened sauces are a separate canning category with their own rules.

Selling syrup made from a soft batch

If you sell, the name has to match what is in the jar.

• Do not sell it as jam or jelly. A jam or jelly sold under its standard name is expected to be a set product. Penn State's commercial primer says nonstandard products must be "informatively labeled so as not to claim to be a standard jam or jelly" [5].
• Name it for what it is, such as "Blackberry Syrup" or "Strawberry Pourable Fruit Spread," and list ingredients by weight in descending order as for any packaged food. What names carry rules is on what you can call your jam.
• The federal policy for nonstandard jellies does not cover syrups. FDA's compliance policy on nonstandardized jellies addresses products named "jelly" [6]; a syrup is a different product, so do not lean on that policy to describe it.
• Check your state list. Many cottage food laws name jams and jellies but not syrups. Whether a fruit syrup is allowed, and whether a relabeled soft jam counts, is your state agency's call.

If what you want is a drinking syrup with vinegar

Shrubs and drinking vinegars start from a fruit syrup too, but they add vinegar, they are usually made without cooking, and they live in the refrigerator. Their method, storage and where they sit under federal rules are on shrubs, drinking vinegars and fermented fruit.

References

1. Penn State Extension, Preserving berries publication (code UK125), 2019, reproducing Blueberry Syrup from So Easy to Preserve, 6th ed., 2014. https://www.ccfruitandnuts.ucanr.edu/sites/default/files/2020-10/337812.pdf
2. Washington State University Extension, Wells-Moses, Preserving Berry Syrups at Home (FS238E), September 2016. https://wpcdn.web.wsu.edu/wp-extension/uploads/sites/2053/2021/06/Preserving-Berry-Syrups-at-Home-FS238E.pdf
3. USDA and National Center for Home Food Preservation, Guide 7: Preparing and Canning Jams and Jellies, rev. July 2015. https://nchfp.uga.edu/papers/guide/GUIDE07_HomeCan_rev0715.pdf
4. Penn State Extension, Zepp, Modified Food Starches, updated December 6, 2023. https://extension.psu.edu/modified-food-starches
5. Penn State Extension, LaBorde, Food for Profit: Commercial Production of Jams, Jellies and Fruit Butters, updated May 24, 2024. https://extension.psu.edu/food-for-profit-commercial-production-of-jams-jellies-and-fruit-butters
6. US Food and Drug Administration, CPG Sec. 550.475 Jellies, Nonstandardized, rev. May 2005, updated November 29, 2005. https://www.fda.gov/regulatory-information/search-fda-guidance-documents/cpg-sec-550475-jellies-nonstandardized