Commercial jam runs in eight steps: prepare and weigh the fruit, measure the sugar and pectin, cook to the set, check the soluble solids, fill the jars hot, seal them, cool them, and code and label. Two steps decide whether it's really jam. The ratio: to be called jam, it needs at least 45 parts fruit to 55 parts sugar by weight, 47 for some fruits. And the soluble solids: at least 65%, read on a refractometer at the end of the cook, which is also what makes a jam set and keep. Filling hot and sealing straight away, as the process calls for, is what lets a jar sit on a shelf for a year. In the example below, a Michigan preserves maker runs a day of tart cherry preserves.
The short version
- Eight steps: prepare, measure, cook, check, fill, seal, cool, code.
- Weigh fruit and sugar: 45 parts fruit to 55 sugar for jam.
- Cook until the soluble solids reach 65%, read on a refractometer.
- Fill hot and seal straight away, as the process calls for.
- New lids for every jar.
- Code each jar with its lot and best-by.
- TaroStack records each kettle as a batch with its fruit lots. More below.
The eight steps
| Step | What happens | What to record |
|---|---|---|
| 1. Prepare | Fruit washed, stemmed, pitted and weighed | Fruit weight, fruit lot |
| 2. Measure | Sugar and pectin weighed for the fruit | Sugar and pectin weights |
| 3. Cook | Brought to a boil and cooked to the set | Time |
| 4. Check | Soluble solids read on a refractometer | Brix reading |
| 5. Fill | Filled hot, headspace checked | Fill temperature |
| 6. Seal | Capped and processed or inverted as the process says | Time |
| 7. Cool | Cooled undisturbed, seals checked | Unsealed jars pulled |
| 8. Code | Lot and best-by on each jar, labels on | Lot, best-by, jars |
What goes on the label is in jam labeling requirements, and the kitchen's food safety plan in jam haccp plan.
The rule behind steps 2 and 4
Jam and preserves have a standard of identity: at least 45 parts fruit to 55 parts sugar, 47 for Group I fruits, and soluble solids of at least 65% (21 CFR 150.160). A product that misses it is sold as a fruit spread, as standard of identity food explains.
An example: a day of tart cherry preserves
Old Mission Preserves, the made-up preserves maker in Traverse City, Michigan, I use in these examples, cooks tart cherry preserves in 20-quart kettles. One July day:
| Step | What happened |
|---|---|
| Prepare | 6 kettles of 18 lb pitted tart cherries, fruit lot TC-0712 |
| Measure | 22 lb of sugar a kettle, 45:55 by the recipe; pectin weighed per kettle |
| Cook and check | 18 to 22 minutes a kettle; refractometer 65.5% to 67%; kettle 4 read 63%, cooked 3 minutes more to 65.5% |
| Fill and seal | 8 oz jelly jars, new lids, filled hot |
| Cool | 312 jars sealed, 2 unsealed jars pulled for the kitchen |
| Code | Lot OM-0712, best by July 2027 |
Kettle 4 came off the heat at 63%, short of the standard, and the refractometer caught it; another three minutes brought it to 65.5%. Without the reading, those 52 jars would have been under the line for jam. What the jars sell for is in how to price jam.
Get the run sheet
Download the jam production run sheet. Two sheets: a blank run sheet to print for each batch, with the eight steps, the check at each and its target, and spaces for the actual reading, the time and initials; and the same run filled in from the example. It's an ordinary Excel file with no macros, and it works in Google Sheets, LibreOffice and Numbers.
Where this stops working
The run sheet covers one day. Six kettles, each with its own refractometer reading, and 312 jars going to markets, gift shops and a grocer: when a cherry lot is recalled, the trace has to run from the lot to every shop.
How TaroStack does it
TaroStack records each kettle as a batch with its fruit and sugar lots, so a jar's lot leads back to its kettle.
Kettles as batches. Each kettle is a batch from the preserves recipe, taking the cherries, sugar and pectin off stock with their lots.
Jars by lot. Each batch gets its lot and best-by, and lot labels print for the jars.
Where it went. Each shop's order records the lots it got, so one recall report runs from the cherry lot to every shop.
| The job | Clipboard | In TaroStack |
|---|---|---|
| Which cherries went into a kettle | A note on the clipboard | Batches by lot |
| Jars made and pulled | Counted at the end | On the batch |
| Which shops got a lot | Invoices | One recall report |
Recipes, batches, lots and recalls are on every plan, from $49 a month. The first 30 days are free, with no credit card. If you'd like a hand setting up, ask, and we'll do it with you.