chef-fermentation-preservation

# Chef Fermentation & Preservation Preservation is process control, not folklore. Salt, acid, temperature, oxygen, water activity and processing time matter in different combinations for different foods. There is no universal `2% = safe` law. Read `references/ferments-and-preserves.md` for the method classes and source policy. ## Method contract For a safety-critical preservation request: 1. Identify the exact product, batch, container, intended storage and equipment. 2. Retrieve/read a matching current authoritative method when tools permit (NCHFP, extension service, public-health authority, or the specific appliance manufacturer). 3. Preserve the method's critical proportions and processing conditions. Do not average two protocols or improvise a missing acid/salt/process value. 4. Give the user the complete usable method yourself: quantities, order, checks, cooling/storage and discard criteria, plus the source. 5. If the method does not match the user's ingredients/equipment, say exactly what is missing and offer the nearest safe alternative. Do not merely tell the user to "find a validated recipe". ## Fermentation Salt percentage is a recipe parameter, not a pathogen certificate. Submersion, temperature and time can matter, but visual/smell cues alone cannot prove a batch safe. If a bundled formula is not tied to a sufficiently applicable method, use it only as culinary orientation and fetch/choose a validated process before making a safety claim. ## Canning Use tested recipes and processing times. Water-bath and pressure-canning are not interchangeable. Low-acid foods commonly require pressure canning; exact time/pressure/altitude/container rules come from the selected tested recipe. A measured pH below a threshold is not by itself permission to invent a shelf-stable process. ## Garlic or herbs in oil For home-prepared **non-acidified garlic in oil**, NCHFP guidance: refrigerate at **4°C/40°F or below for no more than 4 days**, or freeze for longer storage. Never keep it at room temperature. Do not assume a splash of lemon or vinegar creates a validated acidification process. ## Curing, confit and raw seafood A fat cap, salt cure, `sushi-grade` label or home freezer step does not automatically create weeks of safe storage or make raw fish microbiologically safe. Use a product-specific method. Treat confit fat as part of the dish unless a validated preservation procedure says otherwise. ## Starter care and flavor ferments Sourdough starter care can remain culinary and cue-driven because it is not a shelf-stable canning claim. For kombucha, kefir and other beverage/dairy ferments, separate quality troubleshooting from safety claims; mold or a failed process is a discard decision, not a tasting experiment. Project responsibility and source policy: `/DISCLAIMER.md`, `/SAFETY.md`.