Seal: Home Canning Safety

Free to download. Every Pro feature is free for 48 hours, then a single one-time unlock — no subscription, no ads, no account. Works offline. Seal is the iOS companion for USDA-tested home canning. Pick a food, set your altitude, and Seal computes the processing time and pressure for your jar size — cited "Per USDA Complete Guide" or "Per NCHFP" inline so you can verify the number against the source. 42 USDA-tested recipes across fruit, tomato, vegetable, meat, fermented, and jam & jelly chapters. Apple recipes show both Ball 38th Edition (2024 acidified) and USDA 2015 sources where the two diverge — Seal never picks a winner. The Moon Dog wedge for Seal is voice: every number cites the source. No "it is safe to…" framing. The 11-item Pre-process Checklist mirrors Iowa State's "potentially deadly canning mistakes." The symptom-first jar-failure diagnostic answers the canonical "my jar did X, is it safe?" question with 13 USDA / NCHFP / Penn State / Iowa State / CDC-cited rows — bulged-lid and spurting-on-unseal cases lead with the CDC botulism triple-negative ("you cannot see, smell, or taste the toxin") before any disposal copy. Features • 42 USDA-tested recipes, each cited to USDA Complete Guide chapter / NCHFP / Ball 38th — verified against NCHFP canonical pages before ship • Altitude-aware processing: water-bath times extend per USDA Part 1 table; pressure-canner PSI looked up by altitude + gauge type, with explicit warning on the weighted-gauge step from 10 → 15 psi at 1,001 ft • 11-item Pre-process Checklist (Iowa State Extension) — every recipe run starts here; no timer until all 11 are confirmed • Process timer with phase prompts (vent → process → cool-down) — voice via AVSpeechSynthesizer, haptic via CoreHaptics, big readable type for hands-busy moments next to the canner • 13-row symptom-first jar-failure diagnostic — DO NOT OPEN gating on bulged lids and spurting-on-unseal cases with CDC botulism framing • Recipe-Alteration Check — the 2-hour vs 24-hour correction window mapped to the right gating question ("did you follow a tested recipe exactly?") so an altered recipe never gets routed to the 24-hour reprocess path • Pumpkin purée and zucchini / summer squash intercepts — both NOT USDA-approved; named warning fires at the food picker before any processing screen loads • Tomato acidification gate — boundary foods require 2 Tbsp bottled lemon juice per quart or 1/2 tsp citric acid per quart; the timer stays disabled until the user confirms the acidification step • Jar log (SwiftData, on-device) — batch history with recipe, jar size, altitude, time, PSI, lot number For home canners working from the USDA Complete Guide to Home Canning, NCHFP, and the Ball Blue Book. Pressure-canner and water-bath users at any altitude. Free to download, with a one-time unlock for Pro. No subscription, no ads, no account, no cloud. Privacy: Seal collects nothing. No analytics, no accounts, no network requests. Your batch log and settings live on your device. 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. What Seal does not do: generate recipes with AI. Generative AI hallucinating canning process times kills people. Seal only surfaces USDA-tested data with the source named on every screen.