About Jelly Glimmer
Jelly Glimmer is a small set of free calculators for people making jam, jelly, marmalade and chutney at home, whether it is a first batch of Christmas presents or a glut of plums.
How it works
Every number comes from a named source: the tested recipes and tables of the USDA Complete Guide to Home Canning and the University of Georgia, published by the National Center for Home Food Preservation; university extension publications; and, for the British open-pan method, widely used BBC cookery guidance. Each page lists its sources and the date they were checked. Where no tested source covers something, the tools say so rather than guess, and they never shrink the sugar or scale up a recipe.
The calculators run entirely in your browser. Nothing you type is sent anywhere. The site uses Cloudflare Web Analytics, which counts page views without cookies or cross-site tracking and never receives what you type into the tools; the privacy page has the details.
Please read
This is general food-safety information, not professional, medical or legal advice. Home canning is safe when a tested recipe and method are followed exactly. In the US, your county or state Cooperative Extension office can answer canning questions; in the UK, the Food Standards Agency and your local council cover food safety and selling food. If you think someone is ill from home-preserved food, call a doctor or emergency services straight away.
Jelly Glimmer is an independent site with no company behind it and nothing to sell. It links to two free tools from the same owner, CleanTempMail and WebTraceCheck, where they help with a preserving task.