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Seal: Home Canning Safety — Support

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Email roman.kopaliani@gmail.com with your question. Please include:

Common questions

Why does Seal show two sources for some apple recipes?

In 2024 Ball Canning added bottled lemon juice to all apple-based recipes in their 38th Edition Blue Book because modern apple varieties can exceed the pH 4.6 threshold for safe water-bath canning. USDA's 2015 Complete Guide has not adopted this change. Per Iowa State Extension's "Trusted Preservation Resources" guidance, Seal discloses both sources rather than picking a winner: apple recipes default to Ball's 2024 acidified recommendation as the more conservative path, with the USDA 2015 unacidified citation shown as a footnote. You choose which to follow.

Why won't Seal let me water-bath green beans?

Per USDA Complete Guide Part 1, green beans are low-acid (pH > 4.6) and require pressure canning. Water-bath canners cannot reach the temperature needed to destroy Clostridium botulinum spores in low-acid foods. This is Iowa State Extension's "potentially deadly canning mistake #11." Seal enforces the interlock — pick pressure canning, or pick a high-acid food.

Why does the weighted-gauge pressure jump from 10 to 15 psi at 1,001 ft?

Weighted-gauge canners (Presto, All American, Mirro) only support discrete 5 / 10 / 15 psi weights. The USDA Complete Guide Part 1 altitude table accommodates this by stepping to 15 psi as soon as you cross 1,001 ft, then holding 15 psi through 10,000 ft. Beginners near 1,000 ft often miss this step — Seal surfaces an explicit warning when your altitude is within 200 ft of 1,001 ft on a weighted gauge.

Can I can pumpkin purée?

No. Per USDA Complete Guide Part 4, only pumpkin and winter squash chunks are USDA-approved. Purée and mashed pumpkin are too dense to heat-penetrate reliably during processing — there is no tested processing time for purée at any altitude. The recommended approach is to can chunks, then purée at use time (open jar, blend, cook into pie or soup). Seal intercepts "pumpkin purée," "mashed pumpkin," and "pumpkin pie filling" at the food picker.

Can I can zucchini or summer squash?

No. Per NCHFP, zucchini and other summer squash have no USDA-tested processing time. Their density and water content vary unpredictably, and earlier USDA guidance for pressure-canning summer squash was withdrawn due to safety concerns. Freeze, dehydrate, refrigerator-pickle, or use a USDA-tested fermented-pickle recipe instead. Seal intercepts these foods at the picker.

My jar's lid is bulged. What do I do?

Do not open it. Per CDC, "you cannot see, smell, or taste the toxin that causes botulism." A bulged or swelled lid indicates active gas production — possible Clostridium botulinum. Double-bag the unopened jar, wrap in newspaper, place in a sealed garbage can outside, away from children and pets. Do not taste the contents. Wash your hands thoroughly. Sanitize any surfaces with 10% bleach. Inspect all adjacent jars from the same batch. Open the Diagnose tab → "My jar did something" → "Bulged or swelled lid" for the full disposal procedure.

I forgot the lemon juice on a tomato batch. Now what?

It depends on how long ago you processed and whether you altered the recipe further. Open the Diagnose tab → "I altered a recipe" → pick "Forgot lemon juice or citric acid." If you altered the recipe and you're within 2 hours, you can reprocess immediately with the corrected recipe, or refrigerate and eat within 5 days, or freeze. Past the 2-hour window, the contents are no longer salvageable for shelf storage — treat as fresh-cooked or discard. Per Iowa State Extension, the 24-hour reprocess window is only for batches where you followed a tested recipe exactly and only the seal failed.

Does the app work offline?

Yes — Seal never connects to the internet. Recipe data, altitude tables, symptom-diagnostic guidance, and citations are bundled in the app at install time. There are no analytics, no accounts, no cloud sync.

Why is there no AI canning assistant?

Generative AI hallucinating canning process times kills people. Pressure-canning errors cause botulism, and there is no tested processing time for a recipe an LLM invents. Seal is built to surface USDA-tested data with the source named on every screen, full stop.

How do I delete my data?

Delete the app from your iPhone or iPad. All local data — batch log, diagnostic logs, alteration logs — is removed along with it.

Safety reminder

Seal presents USDA / NCHFP / Extension guidance for educational purposes. Follow the latest version of any recipe publication (USDA, NCHFP, cooperative extension, Ball) for authoritative safety information. Consult a Master Food Preserver for borderline cases. When in doubt, follow the most conservative source.