以下为本文档的中文说明该技能涵盖人类数千年来积累的食品保存技术包括发酵、腌渍、罐装、干燥和烟熏等方法。功能是帮助用户延长食物保质期、减少浪费、制作发酵食品泡菜、酸菜、酸奶、面包以及建立食品自给能力。核心观点是在冰箱发明之前人类通过发酵和保存技术维持了上万年的生存这不是过时的爱好而是核心生存技能。一颗卷心菜和一勺盐可以变成保质期六个月的酸菜一堆黄瓜可以变成30罐腌黄瓜一个酸面团发酵剂可以永久使用。核心特点在于从最简单的方法开始逐步深入乳酸发酵只需要盐和容器是最容易入门的然后逐步涉及罐装需要特定设备和严格的安全规范和脱水干燥水果、蔬菜、肉类。每个方法都附有详细的安全规则因为虽然发酵是安全的自然过程但不正确的罐装可能导致肉毒杆菌中毒这种致命的后果。该技能还包含不同国家和地区的标准参考——美国遵循USDA家庭罐装完整指南英国遵循MAFF指南。核心原则是’安全第一、循序渐进’——不鼓励新手一开始就尝试高风险的方法如压力罐装低酸食物而是从乳酸发酵这种几乎零风险的入门方法开始建立信心和技能。对于更高级的技术如罐装肉类、制作发酵香肠要求学习者先掌握基本原理和安全知识后再实践。该技能不仅教授技术更传达一种食品自给和减少浪费的生存哲学强调’知其然更知其所以然’——理解每种保存方法背后的微生物学和化学原理。Fermentation Food PreservationHumans preserved food for 10,000 years before refrigeration existed. Fermentation, drying, salting, smoking, and canning are not quaint hobbies — they’re core survival technology. A $5 head of cabbage and a tablespoon of salt becomes sauerkraut that lasts 6 months. A bushel of cucumbers becomes 30 jars of pickles. A sourdough starter lives forever and costs nothing after day one. This skill covers the practical methods, starting with the easiest (lacto-fermentation, which needs only salt and a jar) and progressing to canning and dehydration. Safety rules for each method are included because botulism is real and preventable.# Localization note - Canning standards: US: USDA Complete Guide to Home Canning (nchfp.uga.edu) UK: MAFF guidelines AU: CSIRO food preservation guidelines CA: Health Canada home canning safety - Altitude affects canning: boiling point decreases with elevation. Above 1,000 ft (305m), processing times and pressures must be adjusted. Agent must ask users altitude for any canning guidance. - Temperature units: Fahrenheit (US) vs Celsius (everywhere else). Provide both for all temperature references. - Measurement: US cups/tablespoons vs metric grams/mL. Fermentation ratios by weight (grams) are more reliable than by volume. - Local food safety authorities vary — swap USDA for equivalent - Jar types: Mason/Ball jars (US/CA), Kilner jars (UK), Le Parfait (EU), Weck (DE). Two-piece lid systems are standard for water bath canning.Sources VerificationUSDA Complete Guide to Home Canning– the definitive US reference for safe canning procedures. https://nchfp.uga.edu/publications/publications_usda.htmlNational Center for Home Food Preservation (NCHFP)– research-based preservation guidance from the University of Georgia. https://nchfp.uga.eduSandor Katz, “The Art of Fermentation”– comprehensive reference on fermentation techniques worldwideBall Blue Book of Preserving– practical canning recipes and procedures, updated regularlyAnthropic, “Labor market impacts of AI”– March 2026 research showing this occupation/skill area has near-zero AI exposure. https://www.anthropic.com/research/labor-market-impactsWhen to UseUser wants to make sauerkraut, kimchi, pickles, or other fermented foodsUser has a garden harvest and needs to preserve itUser wants to start a sourdough bread starterUser wants to learn water bath canning (jams, pickles, tomatoes)User wants to dehydrate foods (jerky, fruit leather, herbs)User wants to reduce food waste by extending shelf lifeUser wants to understand food preservation safety (especially botulism prevention)User is building food resilience and self-sufficiencyInstructionsStep 1: Start with lacto-fermentation (the easiest method)Agent action: This is the entry point for everyone. It requires no equipment, no heat, no special skills. Just salt, vegetables, and a jar.LACTO-FERMENTATION — how it works: THE SCIENCE (simple version): Lactobacillus bacteria are already on your vegetables. Salt creates an environment where Lactobacillus thrives and harmful bacteria cant survive. The bacteria convert sugars into lactic acid, which preserves the food, creates the sour flavor, and makes it probiotic. YOU NEED: - A glass jar (quart/liter Mason jar is ideal) - Fresh vegetables - Non-iodized salt (kosher salt, sea salt, or pickling salt — iodized table salt can inhibit fermentation) - Water (if making a brine — unchlorinated; if your tap water is chlorinated, let it sit uncovered for 24 hours or use filtered) THE UNIVERSAL RATIO: - For dry-salted ferments (sauerkraut, kimchi): 2% salt by weight of the vegetables. For 1 kg (2.2 lbs) cabbage, use 20g salt (about 1 tablespoon). - For brine ferments (pickles, vegetables in liquid): 3-5% brine. For 1 liter water, use 30-50g salt (2-3 tablespoons). BASIC SAUERKRAUT (your first ferment): Ingredients: - 1 medium head green cabbage (about 2 lbs / 900g) - 1 tablespoon (18g) non-iodized salt Method: 1. Remove outer leaves (save one). Quarter cabbage, remove core. 2. Slice thin (1/8 inch / 3mm). A knife works. A mandoline is faster. 3. Put sliced cabbage in a large bowl. Add salt. 4. Massage and squeeze the cabbage with your hands for 5-10 minutes. The salt draws water out of the cells. Youre making your own brine. Keep going until the cabbage is limp and theres liquid pooling in the bottom of the bowl. 5. Pack cabbage tightly into a clean quart jar, pushing down hard with your fist or a wooden spoon. The brine should rise above the cabbage. Leave 1-2 inches of headspace. 6. Place the saved outer leaf on top as a cap to keep shreds submerged. Weight it down (a small jar filled with water works, or a zip-lock bag of brine). 7. Cover loosely (the jar will off-gas CO2 — dont seal airtight or pressure builds. A loose lid, cloth, or airlock all work). 8. Leave at room temperature (65-75F / 18-24C), out of direct sunlight. 9. Check daily. Push cabbage down if it rises above the brine. Skim any white scum (kahm yeast — harmless but ugly). 10. Taste after 3 days. Its done when you like the sourness. Most people prefer 1-3 weeks. 11. Once it tastes right, seal and refrigerate. It lasts 6 months in the fridge. YIELD: 1 medium cabbage 1 quart (1 liter) sauerkraut COST: ~$2-3 per quart (vs $5-8 store-bought for inferior product)Step 2: Fermented pickles and kimchiAgent action: Once the user has made sauerkraut, these are natural next steps using the same principles.FERMENTED DILL PICKLES (brine method): Ingredients: - 2 lbs (900g) small pickling cucumbers (Kirby or similar) - 4 cups (1L) water - 2 tablespoons (36g) non-iodized salt - 4 cloves garlic, smashed - 2 tablespoons dill seed (or a few heads of fresh dill) - 1 teaspoon black peppercorns - 1 grape leaf, oak leaf, or bay leaf (tannins keep pickles crunchy) Method: 1. Dissolve salt in water to make brine. 2. Cut 1/16 inch off the blossom end of each cucumber (contains an enzyme that makes pickles soft). Stem end is fine to leave. 3. Pack cucumbers vertically in a half-gallon jar. 4. Add garlic, dill, peppercorns, and leaf. 5. Pour brine over cucumbers. All cucumbers must be submerged. 6. Weight down. Cover loosely. 7. Room temperature, 3-7 days. Taste daily starting at day 3. Half-sours: 3-4 days. Full sours: 5-7 days. 8. Refrigerate when they taste right. Last 2-3 months. YIELD: 2 lbs cucumbers half-gallon jar of pickles COST: ~$3-4 per half gallon (vs $6-8 store-bought) --- BASIC KIMCHI: Ingredients: - 1 medium napa cabbage (about 2 lbs / 900g) - 1/4 cup (72g) non-iodized salt - 1 tablespoon grated fresh ginger - 4 cloves garlic, minced - 2-4 tablespoons gochugaru (Korean red pepper flakes — available at Asian grocery stores; regular red pepper flakes work but taste different) - 1 tablespoon fish sauce (or soy sauce for vegan version) - 1 teaspoon sugar - 4 scallions, cut into 1-inch pieces - 1 medium daikon radish or carrots, julienned (optional) Method: 1. Quarter cabbage, cut into 2-inch pieces. 2. Toss with salt in a large bowl. Let sit 1-2 hours, tossing occasionally. Cabbage will wilt and release water. 3. Rinse cabbage 3 times under cold water to remove excess salt. Squeeze out water. 4. Mix ginger, garlic, gochugaru, fish sauce, and sugar into a paste. 5. Combine cabbage, paste, scallions, and radish/carrots. Mix thoroughly with gloved hands (gochugaru stains and burns). 6. Pack into a jar. Press down until brine covers vegetables. 7. Leave 2 inches headspace (kimchi is active — it bubbles a lot). 8. Room temperature 2-5 days. Burp the jar daily (open lid to release CO2). 9. Taste at day 2. Refrigerate when tangy enough for your taste. 10. Gets more sour over weeks in the fridge. Lasts 3-6 months. YIELD: 1 cabbage 1 quart kimchi COST: ~$4-5 per quart (vs $8-12 store-bought)Step 3: Water bath canning (high-acid foods)Agent action: This is where safety becomes critical. Botulism prevention rules are non-negotiable. Ask the user’s altitude before providing processing times.WATER BATH CANNING — for HIGH-ACID foods only WHAT YOU CAN SAFELY WATER-BATH CAN: - Fruits and fruit jams/jellies (naturally high acid) - Pickles in vinegar (vinegar provides the acid) - Tomatoes with added acid (2 tablespoons lemon juice per quart) - Salsa (tested recipe only — acid balance matters) - Fruit butters and chutneys WHAT YOU CANNOT SAFELY WATER-BATH CAN: - Vegetables without vinegar (green beans, corn, peas) - Meat or fish - Soups or stews - Anything low-acid without added vinegar - These REQUIRE pressure canning at 240F/116C to kill botulism spores. Water bath canning only reaches 212F/100C. EQUIPMENT ($30-50 total): [ ] Large pot with lid (deep enough to cover jars by 1-2 inches of boiling water) — or a dedicated canner with rack ($20-30) [ ] Mason jars with two-piece lids (jar band flat lid) Jars: reusable forever. Bands: reusable. Flat lids: use once. [ ] Jar lifter ($5-8) — essential for safely removing hot jars [ ] Wide-mouth funnel ($3-5) — for filling jars without mess [ ] Bubble remover / headspace tool ($3) THE PROCESS: 1. Sterilize jars: boil in canner for 10 minutes (or run through dishwasher sanitize cycle) 2. Prepare your recipe (use TESTED recipes only — NCHFP, Ball Blue Book, or USDA-approved. Do NOT modify acid ratios, salt amounts, or thickeners. These are tested for safety, not just taste.) 3. Fill hot jars with hot product. Leave headspace as specified (typically 1/4 inch for jams, 1/2 inch for most other products). 4. Remove air bubbles: slide the bubble tool along the inside of the jar. 5. Wipe jar rim clean with a damp cloth (any residue prevents seal). 6. Place flat lid on jar, screw band on fingertip tight (snug but not wrenched). 7. Lower jars into boiling water. Water must cover lids by 1-2 inches. 8. Start timing when water returns to a full boil. 9. Process for the time specified in your recipe. ALTITUDE ADJUSTMENT (critical): - Sea level to 1,000 ft: use recipe time as written - 1,001-3,000 ft: add 5 minutes - 3,001-6,000 ft: add 10 minutes - 6,001-8,000 ft: add 15 minutes - 8,001-10,000 ft: add 20 minutes AFTER PROCESSING: 1. Remove jars with lifter. Set on a towel on the counter. 2. Do not touch or tilt for 12-24 hours. 3. Youll hear ping sounds as lids seal (the lid gets sucked down). 4. After 24 hours, press center of each lid. If it doesnt flex, its sealed. If it pops up and down, it didnt seal — refrigerate and use within 2 weeks. 5. Remove bands for storage (they can trap moisture and cause rust). 6. Label with contents and date. 7. Properly canned high-acid foods last 12-18 months in a cool, dark place.Step 4: Dehydration (jerky, fruit leather, herbs)Agent action: Dehydration is one of the simplest preservation methods. A $40 dehydrator works, but an oven on low does too.DEHYDRATION: EQUIPMENT: - Food dehydrator ($35-60 for a basic Nesco or Presto model) — most efficient option, consistent results - OR: oven on lowest setting (170-200F / 75-93C) with door cracked open. Works but uses more energy and requires monitoring. BEEF JERKY: 1. Use lean cuts (top round, eye of round, flank steak). Fat goes rancid — trim all visible fat. 2. Partially freeze for 1-2 hours (makes slicing easier). 3. Slice 1/4 inch thick, against the grain for tender jerky, with the grain for chewy jerky. 4. Marinate 4-24 hours in fridge: Basic marinade per 1 lb meat: 1/4 cup soy sauce, 1 tablespoon Worcestershire, 1 teaspoon garlic powder, 1 teaspoon onion powder, 1/2 teaspoon black pepper, optional: 1 teaspoon smoked paprika, hot sauce to taste. 5. Pat strips dry. Lay flat on dehydrator trays, not touching. 6. Dehydrate at 160F (71C) for 4-6 hours. 7. USDA safety note: heat meat to 160F (71C) internal temp before or during dehydrating to kill pathogens. Some people pre-heat strips in a 275F oven for 10 minutes before dehydrating. 8. Done when strips crack but dont break when bent. 9. Store in a irtight container or vacuum-seal. Lasts 1-2 months at room temp, 6 months vacuum-sealed. YIELD: 1 lb raw meat about 1/3 lb jerky (meat loses 2/3 of its weight in water) COST: ~$5-6/lb jerky from $8-10/lb meat (vs $20-30/lb store-bought) FRUIT LEATHER: 1. Puree fruit in a blender (any fruit works — strawberry, apple, peach, mango, mixed berry). 2. Add sweetener if needed (1-2 tablespoons honey per 2 cups puree). 3. Spread 1/8 inch thick on parchment-lined dehydrator tray or baking sheet. 4. Dehydrate at 135F (57C) for 8-12 hours. 5. Done when tacky but not sticky. Peel off parchment easily. 6. Roll in parchment paper, store in airtight container. 7. Lasts 1 month at room temp, 6 months in freezer. HERBS: 1. Wash and dry thoroughly (any moisture mold). 2. Remove leaves from stems for small-leaf herbs (thyme, oregano). Leave large leaves whole (basil, mint). 3. Dehydrate at 95-115F (35-46C) for 2-4 hours. Low temp preserves volatile oils (flavor). 4. Done when leaves crumble between fingers. 5. Store whole (crumble when using — whole leaves retain flavor longer). 6. Dried herbs last 1-3 years in airtight jars away from light.Step 5: Sourdough starterAgent action: A sourdough starter is a living culture. Once established, it lasts forever with feeding. This takes 7-10 days to build from scratch.SOURDOUGH STARTER FROM SCRATCH: YOU NEED: - All-purpose flour or whole wheat flour (whole wheat starts faster due to more wild yeast on the bran) - Water (unchlorinated — filtered or left to sit 24 hours) - A glass jar (quart size) - A kitchen scale (strongly recommended — weighing is far more accurate than measuring cups for this) DAY 1: - Mix 50g flour 50g water in jar. Stir well. - Cover loosely (cloth, loose lid). Room temperature. DAY 2: - Look for bubbles. Probably none yet. Thats normal. - Discard half the starter. Add 50g flour 50g water. Stir. DAYS 3-5: - Repeat daily: discard half, feed 50g flour 50g water. - By day 3-4, you should see bubbles and a slightly sour smell. - If it smells like nail polish remover (acetone): its hungry. Feed more frequently (twice a day). DAYS 6-10: - The starter should be rising predictably — doubling in size within 4-8 hours of feeding. - When it reliably doubles in 4-8 hours, its ready to bake with. - Total flour cost to build a starter: about $0.50. MAINTAINING YOUR STARTER: - If baking weekly: keep on counter, feed daily (discard half, add equal parts flour and water) - If baking less often: store in fridge. Feed once a week. Take it out and feed twice before baking (to reactivate). - Discard isnt waste — use it for pancakes, waffles, crackers, pizza dough. Search sourdough discard recipes. YOUR STARTER IS DEAD IF: - Covered in pink, orange, or fuzzy mold throw out, start over - No activity after 14 days of daily feeding start over - Black liquid on top (hooch) its not dead, just hungry. Pour off the liquid and feed it. Itll recover.Step 6: Quick vinegar picklingAgent action: Fastest preservation method. Pickles in 30 minutes. No fermentation wait.QUICK VINEGAR PICKLES (refrigerator pickles): BASIC BRINE: - 1 cup vinegar (white, apple cider, or rice — 5% acidity minimum) - 1 cup water - 1 tablespoon salt - 1 tablespoon sugar (optional, balances acid) - Bring to a boil, stir to dissolve salt and sugar. PICKLE ANYTHING: - Cucumbers (classic dill pickles) - Red onions (for tacos, sandwiches, salads) - Carrots and daikon (Vietnamese banh mi style) - Jalapenos - Green beans (dilly beans) - Cauliflower - Radishes METHOD: 1. Slice or prepare your vegetables. 2. Pack into a clean jar with spices: - Dill pickles: garlic, dill, peppercorns, mustard seed - Spicy: red pepper flakes, garlic, coriander - Sweet: cinnamon stick, cloves, allspice (for fruit pickles) 3. Pour hot brine over vegetables. Let cool. 4. Refrigerate. Ready in 30 minutes (improve over 24-48 hours). 5. Last 2-3 months in the fridge. COST: ~$1-2 per jar. Vinegar is cheap. Spices last forever. FO R SHELF-STABLE PICKLES: Use the water bath canning process from Step 3 with a tested recipe. Quick pickles are fridge-only unless properly canned.Botulism Prevention (critical safety section)BOTULISM — what it is and how to prevent it WHAT: Clostridium botulinum bacteria produce a toxin that causes paralysis and death. The spores survive boiling (212F/100C). They thrive in anaerobic (no oxygen), low-acid, moist environments — which describes the inside of an improperly canned jar perfectly. PREVENTION RULES (non-negotiable): 1. NEVER water-bath can low-acid foods (vegetables, meat, soups). These require pressure canning at 240F/116C for the required time. 2. ALWAYS use tested recipes from USDA, NCHFP, or Ball. Do not modify acid levels, proportions, or thickeners. 3. ALWAYS add acid to borderline foods: tomatoes need 2 tablespoons lemon juice or 1/2 teaspoon citric acid per quart. 4. NEVER use damaged or unsealed jars. 5. NEVER taste food from a jar with a bulging lid, broken seal, or off smell. Discard without tasting. 6. When in doubt, boil the food for 10 minutes before eating (heat destroys the toxin, though not the spores). FERMENTATION IS SAFE because: - The acidic environment (lactic acid) prevents C. botulinum growth - This is why proper salt ratios matter — they ensure Lactobacillus dominates and lowers pH before harmful bacteria can establish SIGNS OF BOTULISM IN CANNED FOOD: - Bulging lid - Leaking jar - Spurting liquid when opened - Off smell or appearance - Mold on the surface - Any of these discard the entire jar without tastingIf This FailsSauerkraut is slimy or smells rotten: Discard it. Likely too warm (above 80F/27C) or not enough salt. Retry with accurate salt measurement (2% by weight) at 65-75F (18-24C).Fermented pickles are soft/mushy: The blossom end wasn’t removed (it contains an enzyme that softens pickles), or fermentation went too long. Add a grape leaf or oak leaf next time — tannins help crunchiness.Canned jar didn’t seal: Refrigerate and use within 2 weeks. Or reprocess within 24 hours with a new lid. Don’t force it — an unsealed jar at room temperature is a botulism risk.Sourdough starter won’t rise: Use whole wheat flour for a few feedings (more wild yeast). Move to a warmer spot (75-80F/24-27C). Feed twice daily instead of once. If no activity after 14 days, start over.Mold on ferment: If it’s white surface scum (kahm yeast), skim it off — the ferment below is fine. If it’s fuzzy, black, pink, or orange mold, discard everything.RulesNever water-bath can low-acid foods. This is the #1 rule of canning safety and the one most commonly broken by well-meaning people sharing grandma’s “recipe.” Botulism is odorless and tasteless.Use tested recipes for all canning. Do not modify acid ratios, thickeners, or proportions. Safety testing is specific to the exact recipe.Keep ferments submerged. Vegetables above the brine are exposed to air and will mold. Weight them down.Use non-iodized salt for fermentation. Iodine inhibits the beneficial bacteria you’re trying to cultivate.Label everything with contents, date, and method. “Mystery jar from sometime last year” is not a food safety strategy.TipsLacto-fermentation is the gateway skill. If you can make sauerkraut, you can make kimchi, fermented hot sauce, fermented salsa, preserved lemons, and dozens of other fermented foods with the same technique (salt vegetable jar time).Kitchen scale measuring cups for fermentation. The 2% salt ratio by weight is reliable. “A tablespoon” varies depending on salt crystal size by up to 40%.The “discard” from sourdough starter is a cooking ingredient, not waste. Sourdough discard pancakes, waffles, and crackers are excellent and use a product most people throw away.Canning is seasonal work. Do it during harvest season when produce is cheapest and most abundant. A weekend of canning in August can stock your pantry through March.Fermentation connects directly to the grow-food-anywhere skill. A small garden producing more tomatoes or cucumbers than you can eat in a week is not a problem — it’s a preservation opportunity.Start with one method and get comfortable before branching out. Sauerkraut first, then pickles, then canning. Trying everything at once leads to overwhelm and wasted food.Agent Statepreservation:methods_practiced:[]current_project:nullferments_active:[]canned_inventory:[]equipment_owned:[]altitude_ft:nullfermentation:sauerkraut_made:falsekimchi_made:falsepickles_made:falsesourdough_starter_active:falsestarter_age_days:nullstarter_feeding_schedule:nullcanning:has_equipment:falsehas_tested_recipes:falseknows_botulism_rules:falsealtitude_adjustment_known:falsedehydration:has_dehydrator:falsejerky_made:falsefruit_leather_made:falseherbs_dried:falseAutomation Triggerstriggers:-name:first_ferment_guidancecondition:fermentation.sauerkraut_made IS false AND preservation.current_project IS SETaction:If youre new to preservation, start with sauerkraut. Its the simplest ferment — just cabbage, salt, and a jar. No special equipment, no heat, no risk of botulism. Let me walk you through it.-name:canning_safety_checkcondition:preservation.current_project CONTAINS canning AND canning.knows_botulism_rules IS falseaction:Before we start canning, lets cover botulism prevention. This is the one area of food preservation where mistakes can be fatal. It takes 5 minutes to learn the rules that keep you safe.-name:altitude_checkcondition:preservation.current_project CONTAINS canning AND preservation.altitude_ft IS nullaction:I need your altitude before giving canning times. Processing times must be adjusted above 1,000 feet. Whats your elevation? (Check your city on Google if unsure.)-name:sourdough_feeding_remindercondition:fermentation.sourdough_starter_active true AND fermentation.starter_feeding_schedule counterschedule:dailyaction:Sourdough feeding reminder: discard half, add equal parts flour and water. If youre not baking this week, consider moving it to the fridge where it only needs weekly feeding.-name:harvest_preservation_promptcondition:user_context CONTAINS garden OR user_context CONTAINS harvestschedule:August 1 annuallyaction:Peak harvest season. If your garden is producing more than you can eat, nows the time to preserve. What do you have coming in? Ill recommend the best preservation method for each crop.