Chemistry & Improvised Materials Science
Everything you can make from raw materials: soap, alcohol, charcoal, candles, leather, lime, adhesives, and more. Every process with safety callouts.
- Never use aluminum containers with lye — violent reaction produces hydrogen gas and destroys the container
- Always add lye to water, never water to lye — reverse causes violent heat spike and spattering
- Methanol in distillate foreshots is odorless and causes blindness/death — always discard first 50ml per 20L wash
- Quicklime + water is exothermic and can cause burns and fires on contact with combustibles
- Work outdoors or with ventilation for all processes involving heat, acid, or volatile compounds
1. Soap Making
Lye from Wood Ash
Lye (potassium hydroxide, KOH) is extracted by leaching water through hardwood ash. Softwood ash produces weaker lye; hardwood ash from oak, hickory, beech, or maple is best.
Float Test Reference
| Result | Lye Concentration | Action |
|---|---|---|
| Object sinks | Too weak (<10%) | Boil to concentrate, or run through more ash |
| Float with dime-sized area above surface | Correct (~25–30% KOH) | Ready for soap making |
| Object floats very high (>50% above) | Too strong | Dilute with water, re-test |
Cold Process Soap — Exact Saponification Values
Saponification is the chemical reaction between fat and lye that produces soap and glycerin. Each fat requires a specific amount of lye to saponify completely. Use these values to calculate recipes:
| Fat / Oil | KOH (lye) per gram of fat | NaOH per gram of fat | Result Properties |
|---|---|---|---|
| Lard (pork fat) | 0.190g | 0.138g | Hard, white, mild — excellent all-purpose |
| Tallow (beef/mutton) | 0.193g | 0.140g | Very hard, white, long shelf life |
| Coconut oil | 0.257g | 0.190g | High lather, cleansing, can be drying |
| Olive oil | 0.189g | 0.134g | Soft, conditioning, slow to harden |
| Palm oil | 0.199g | 0.141g | Hard bar, stable lather, long shelf life |
| Sunflower oil | 0.194g | 0.134g | Skin-conditioning, soft bar |
| Castor oil | 0.180g | 0.128g | Boosts lather; use max 5–10% of recipe |
| Bear/duck fat | ~0.191g | ~0.139g | Similar to lard; use lard values |
Cold Process Recipe — Basic (1 kg batch)
Simple Tallow/Lard Soap
- 700g lard or tallow (or mixed)
- 300g coconut oil (if available; otherwise use all lard)
- 140g sodium hydroxide (NaOH) for hard bar soap — or equivalent KOH for soft soap
- 330ml water (distilled or rainwater ideal)
- Dissolve lye in water (not reverse) — solution heats to 80°C+. Set aside to cool to ~40°C.
- Melt fats to ~40°C. Both lye solution and fats should be similar temperature.
- Slowly pour lye solution into fats while stirring. Never stop stirring.
- Stir (or stick-blend) until mixture reaches "trace" — thick consistency like pudding. Drizzled soap on surface holds a trace line.
- Pour into molds (wood boxes lined with fabric, or silicone molds).
- Cover with towel; insulate for 24–48 hours (the "gel phase" — heat helps saponification complete).
- Unmold after 48–72 hours. Soap is still caustic at this stage — handle with gloves.
- Cut into bars. Cure on an open rack for 4–6 weeks minimum. Water evaporates; pH drops; soap hardens.
Hot Process Soap — Faster, More Forgiving
Hot process soap is cooked after trace, which completes saponification before curing. Ready to use in days rather than weeks.
- Follow cold process to trace.
- Transfer to oven-safe container (crockpot ideal). Cook at 70–80°C.
- Stir every 15–20 minutes. Soap will go through phases: applesauce → taffy → Vaseline texture.
- At Vaseline stage (~60–90 min), test with pH strip (should be 8–10) or zap test (no zing).
- Add any fragrance or botanicals now (heat would destroy them earlier).
- Pack into molds quickly — hot process soap is thick and doesn't pour.
- Usable after 1–2 days. Benefits from a 2–4 week cure for hardness.
Liquid Soap (Soft Soap)
Use potassium hydroxide (KOH) from wood ash rather than sodium hydroxide (NaOH). KOH produces a soft/liquid soap; NaOH produces a hard bar. Follow the same cold process recipe using KOH values from the saponification table. Dilute the finished paste with distilled water to desired consistency.
Medicinal Soap Additives
| Additive | Amount | Properties | When to Add |
|---|---|---|---|
| Pine tar | 5–10% of oil weight | Antimicrobial, antifungal, antiparasitic; treats skin conditions including mange and ringworm | At trace |
| Activated charcoal | 1 tsp per batch | Draws toxins and bacteria; good for acne and infected skin | At trace |
| Calendula infusion | Replace water with infused water | Anti-inflammatory; gentle on wounds and rashes | As lye water component |
| Lavender/tea tree oil | 1–3% of oil weight | Antimicrobial, insect-repelling; fragrance for morale | At trace (cooled) |
| Honey | 1 tbsp per kg | Humectant, antimicrobial; adds lather | At trace |
2. Alcohol Production
Fermentation Basics
Yeast converts fermentable sugars into ethanol and CO₂. Any source of fermentable sugar can produce alcohol. Temperature, nutrient availability, and yeast strain determine efficiency and flavor.
Wash Recipes
Sugar Wash (Fastest, Simplest)
20L water + 5kg white sugar + 1 packet bread yeast + 1 tsp yeast nutrient (or crushed vitamin B tablet). Ferments in 5–7 days at 20–25°C. Produces a clean, neutral alcohol wash. Starting specific gravity (SG) ~1.090; finished ~1.000.
Corn Mash (Bourbon-Style)
5kg cracked corn + 20L water. Heat to 70°C, add 1 cup malted barley (or amylase enzyme), hold 60°C for 60 min (converts starch to sugar). Cool to 30°C. Add yeast. Ferments 7–14 days. More complex flavor; lower ABV wash than sugar.
Fruit Wine
Crush ripe fruit (apples, grapes, pears, berries). Add water to desired consistency. Test brix (sugar level) — ideally 20–25 brix for 10–12% ABV. Add yeast (wild from fruit skins or cultured). Ferment 7–21 days until bubbling stops. Rack off sediment; age if possible.
Grain Beer (Simple)
Malt any grain (allow to germinate 3–4 days, then dry and crack). Steep in hot water at 65°C for 60 min (mash). Drain sweet wort. Boil 60 min; add hops if available (or yarrow, juniper). Cool to 20°C. Add yeast. Ferments in 1–2 weeks. Lower ABV (~4–6%) but nutritious and safer to drink than untreated water when properly fermented.
Pot Still Construction
POT STILL — COPPER PIPE / PRESSURE COOKER METHOD
──────────────────────────────────────────────────────────────
[Thermometer port]
│
┌────────────────────┴────────────────────┐
Lid →│ PRESSURE COOKER │← 15–20L capacity
│ (your pot/boiler) │
└─────────────────┬───────────────────────┘
│ (copper tube sealed
│ through lid port)
│
┌─────┴──────┐
│ LYNE ARM │← 1–1.5" copper pipe
│ (angled │ angled ~30° downward
│ downward) │
└─────┬──────┘
│
┌────────────┴──────────────┐
│ CONDENSER COIL │← 3/8" or 1/2"
│ (10–15 feet 3/8" copper │ copper tubing
│ coiled in cold water │ coiled ~15 loops
│ bucket or cold stream) │
└────────────┬──────────────┘
│
Collection
vessel (glass)
│
[Parrot / hydrometer cup
to measure proof live]
MATERIALS:
• Pressure cooker or large stockpot with lid
• Copper tubing 3/8" OD (10–15 feet for condenser)
• Food-grade silicone or copper ferrule for lid connection
• Large container for condenser cooling water
• Glass collection vessels
• Thermometer (reads 75–100°C range)
SEALING: Rye flour + water paste seals joints temporarily.
Food-grade silicone sealant is better.
Never use lead solder — lead poisoning.
──────────────────────────────────────────────────────────────
The Cuts — What to Keep and What to Discard
| Fraction | Amount (per 20L wash) | Temp Range | What It Contains | Action |
|---|---|---|---|---|
| Foreshots | First 50–100ml | ~65–72°C | Methanol, acetone, acetaldehyde — toxic compounds that concentrate first | DISCARD. No exceptions. Store separately to avoid accidental use. |
| Heads | Next 100–200ml | ~72–78°C | Acetaldehyde, esters — harsh, solvent-like flavor. Some methanol still present. | DISCARD or set aside for cleaning solvent only (not for drinking) |
| Hearts | Middle portion (majority) | ~78–82°C | Primarily ethanol and water. Clean, smooth flavor. | KEEP. This is your product. |
| Tails | Final portion | >82°C | Fusel oils (higher alcohols), water, congeners. Harsh flavor, some useful compounds. | Set aside; can be added to next run for efficiency or discard |
Proofing — Measuring Alcohol Content
- Hydrometer (alcohol meter): Drop into collected distillate; reads ABV (alcohol by volume) directly. Most accurate. Alcohol hydrometers read 0–100% ABV; different from brewing hydrometers which read sugar content.
- Flame test: Dip wick or paper in distillate; light it. Burns with clear blue flame = 50%+ ABV. Burns with yellow flame = 40–50% ABV. Doesn't burn = <40% ABV. Imprecise but useful when no hydrometer is available.
- Target for antiseptic use: 70–90% ABV. Above 90% is actually less effective as a disinfectant (needs some water to denature proteins properly).
Uses by Proof Level
| Proof / ABV | Use | Notes |
|---|---|---|
| 5–14% (beer/wine) | Drinking, food preservation, vinegar mother | Safe to drink if properly fermented and cuts applied to distillate |
| 40–50% (spirits) | Drinking (morale), trade good, flavor extracts | Standard "whiskey/vodka" proof; long shelf life |
| 70–90% (high proof) | Antiseptic (wound care, surface disinfection), tinctures | Must be above 70% to kill pathogens reliably |
| 85%+ (near-pure ethanol) | Fuel (E85 compatible engines), stove alcohol, fire starting | Can run modified engines; excellent camp stove fuel; burns clean |
3. Charcoal & Activated Charcoal
Charcoal Production
Retort Method (Best Quality)
Seal wood in a metal container (barrel with tight lid, capped pipe sections, metal tin). Apply external heat. Volatile gases escape through a small vent but oxygen cannot enter — wood carbonizes without combusting. The vent gases can be ignited and burned to supply heat (closed-loop). Opens when coals are grey and no more smoke emerges. Do NOT open while hot — oxygen will ignite the charcoal.
Best woods: Hardwoods (oak, hickory, maple, fruitwood) produce dense, hot-burning charcoal. Softwoods produce lighter, faster-burning charcoal. Coconut shells and bamboo produce excellent charcoal.
Pit/Mound Method (Traditional, Lower Quality)
Stack wood tightly in a pit or mound. Cover with earth, sod, or damp leaves leaving small air holes. Light from the bottom; allow to smolder 24–48 hours. Carefully seal all holes once burning begins. Too much air = combustion (ash, not charcoal). Too little = incomplete carbonization. Takes practice to read the smoke color — white/blue smoke = still cooking; clear/no smoke = done.
RETORT CHARCOAL KILN (Steel Barrel)
──────────────────────────────────────────────
┌─────────┐
Lid │▓▓▓▓▓▓▓▓▓│← Tight-fitting lid (clamp or bolt)
│ │ Small vent pipe through lid
│ WOOD │← Pack tightly; no gaps
│ CHARGE │ (billets 6–12" long)
│ │
└────┬────┘
│ ← External fire surrounds barrel
═════╪═════ (or barrel sits in fire pit)
│
▼
Vent gases escape and can be burned
to provide heat (efficient method)
SIGNS OF COMPLETION:
✓ No more smoke from vent
✓ Vent gases no longer ignitable
✓ Wait for barrel to cool completely before opening
✓ Do NOT open while hot — instant ignition
──────────────────────────────────────────────
Activated Charcoal
Regular charcoal has limited adsorption capacity. Activated charcoal has been processed to create an enormous surface area (1 gram can have 500–3,000 m² of surface area) that adsorbs toxins, gases, heavy metals, and pathogens.
Steam Activation
- Produce regular charcoal (retort method preferred).
- Heat charcoal to 900–1,100°C in a metal retort or kiln.
- Inject steam (from a boiling water pot connected via pipe) at this temperature for 30–60 minutes.
- Steam erodes the char structure, creating the porous surface. Cool under sealed conditions.
- Result is noticeably lighter, more friable, and deeply black compared to regular charcoal.
Chemical Activation (Zinc Chloride Method)
- Mix wood shavings or sawdust with a concentrated zinc chloride solution (dissolve ZnCl₂ in water to make 60–80% solution).
- Soak wood material 24 hours. Drain excess.
- Heat to 600°C in retort — zinc chloride inhibits tar formation and creates pores.
- Wash finished product thoroughly with hot water to remove zinc chloride — residual zinc is toxic.
Uses of Charcoal & Activated Charcoal
Water Filtration
Adsorbs organicsRemoves taste/odorCrush to 1–3mm granules. Layer in filter column (sand → gravel → charcoal → gravel → sand). Does NOT remove bacteria/viruses alone — must follow with boiling or UV.
Poisoning Treatment
Adsorbs toxinsEmergency use50–100g activated charcoal in 8oz water, taken within 1 hour of ingestion. Adsorbs many poisons before absorption. Does NOT work for: cyanide, heavy metals, alcohols, caustics. Call poison control if available.
Wound Deodorizing
Infected woundsActivated charcoal poultice on infected wounds reduces odor and may adsorb some toxins. Not a substitute for debridement and antibiotics but useful adjunct in austere conditions.
Blacksmithing Fuel
Forge fuel Charcoal preferredCharcoal was the original blacksmithing fuel before coal. Burns hot and clean. Requires 2–3x more charcoal by weight than coal for equivalent heat, but can be produced anywhere wood is available.
Biochar (Soil Amendment)
Agriculture Long-term fertilityCrushed charcoal added to soil creates habitat for beneficial microorganisms, improves drainage and water retention, and locks carbon for centuries. Charge with compost before adding (raw biochar can temporarily decrease fertility by adsorbing nutrients).
4. Candles & Oil Lamps
Caloric Cost Comparison
Approximate calories burned per hour of light (equivalent light output)
Oil lamps are the most calorie-efficient light source. Use them over candles when possible for long-term scenarios. Prioritize natural light — schedule tasks in daylight.
Tallow Candles
- Render fat: Chop kidney fat or other hard fat into small pieces. Melt slowly in water bath at low heat. Strain through cloth. Rendered tallow is white, odorless when cool. Discard crackling and solids.
- Wick materials: Cotton twine (braid 3 threads); rush pith (stripped inner stem of bulrush — traditional rush light); linen cord. Avoid synthetic materials — toxic fumes. Pre-treat wick by soaking in molten tallow or a solution of borax and salt (prolongs burn and reduces mushrooming).
- Molds: Rolled paper tubes; hollowed-out tin cans; clay molds; wooden channels. Hang wick through center; pour melted tallow; cool at room temperature. Takes 1–4 hours to fully solidify.
- Rush lights: Soak dried rush stems in molten tallow; drain; hang to cool. Burn faster than formed candles but require no mold.
Beeswax Candles
Beeswax requires no rendering — melt at 62°C and pour. Burns longer, brighter, and cleaner than tallow with a pleasant honey scent. Requires no wick treatment. The premium candle material. Reserve beeswax for situations where burn quality matters (medical procedures, fine work). Cotton wick at 1:1 height-to-diameter ratio.
Oil Lamps
OIL LAMP — SIMPLE RESERVOIR TYPE
──────────────────────────────────────────────
[Flame]
│
┌──────┴──────┐
│ Wick │← Cotton or plant fiber
│ (rises │ twisted tight
│ by │ 1/4" diameter for
│ capillary)│ bright light
└──────┬──────┘
│
┌──────┴──────────────────────┐
│ Oil reservoir │← Any non-porous
│ (clay bowl, tin can, │ container
│ glass jar, stone dish) │
│ Fill with oil │
└─────────────────────────────┘
OILS THAT WORK:
Best: Olive oil (cleanest, least smoke)
Good: Lard oil (rendered to liquid consistency)
Good: Fish oil (smells, but burns well)
Fair: Vegetable oil (sunflower, canola, corn)
Poor: Mineral oil (petroleum — not renewable)
Avoid: Motor oil (toxic fumes)
WICK CHANNEL: Punch small hole in lid or use
notched clay to hold wick at 45° angle in oil.
Wick should have 1/4" above oil surface.
──────────────────────────────────────────────
5. Tanning Hides
Rawhide vs. Tanned Leather
| Type | Process | Properties | Best Uses |
|---|---|---|---|
| Rawhide | Dehaired, dried under tension (no tanning) | Rock-hard when dry; flexible when wet; shrinks dramatically as it dries | Lashing, tool handles, drum heads, containers, knife sheaths, snowshoe webbing |
| Brain-tanned | Brains emulsified and worked into hide | Soft as cloth, extremely comfortable; not waterproof unless smoked | Clothing (buckskin shirts, gloves, moccasins), bags, sleeping skins |
| Bark-tanned | Tannin from bark slowly penetrates hide | Stiff, durable, moderately water-resistant; quality improves with time | Boots, harness, straps, saddles, armor, book covers |
| Alum-tawed | Aluminum sulfate + salt | White, soft, fine-grained; not waterproof | Gloves, book binding, fine garments |
Brain Tanning — Step by Step
Vegetable (Bark) Tanning
Bark tanning uses plant tannins (tannic acid) to chemically bind with collagen proteins in the hide, creating a stable, durable leather.
Best tannin sources: Oak bark (highest tannin content), hemlock bark, chestnut bark, sumac leaves and twigs, black walnut hulls, mimosa bark.
- Prepare bark: Peel fresh bark; dry and grind or crush. Steep in water 24–48 hours to make tannin solution (tea). Bark tea should be dark brown and astringent to taste.
- Prepare hide: Flesh and dehair as above. Soak in weak tannin solution first ("puering") for 1–2 weeks, then transfer to progressively stronger solutions.
- Pit tanning: Dig pit or use barrel. Layer alternating hide and fresh bark. Fill with water. Hides must be fully submerged. Weight them down. Visit weekly; add fresh bark as tannin depletes. Process takes 3–12 months for thick hides (shoe-sole leather).
- Finishing: Remove when hide is uniformly tan-colored throughout thickness. Wash. Apply grease (neatsfoot oil, tallow, cod liver oil) while damp. Allow to dry under slight tension. Work leather while drying to soften.
What Leather Can You Make?
| Hide Source | Thickness | Best Tanning Method | Products |
|---|---|---|---|
| Deer, elk | Medium | Brain tan | Gloves, shirts, moccasins, bags — the softest leather |
| Cowhide (thin) | Thin-medium | Bark or alum | Harness, straps, belts, light boots |
| Cowhide (thick) | Thick | Bark (slow) | Sole leather, armor, saddles, heavy straps |
| Pig skin | Medium | Bark or brain | Gloves, clothing, bags |
| Sheep/goat skin | Thin | Alum or brain | Book binding, fine gloves, clothing, bags |
| Rabbit, squirrel | Very thin | Brain tan only | Fur-on: insulation, decorative; fur-off: very delicate items |
6. Lime & Mortar
Making Quicklime
Limestone (calcium carbonate, CaCO₃) heated above 900°C decomposes into quicklime (calcium oxide, CaO) and carbon dioxide. Quicklime is the foundation of mortar, limewash, and agricultural lime.
Slaking Quicklime
Slaking converts quicklime (CaO) to hydrated lime / slaked lime (Ca(OH)₂) by adding water. Slaked lime is the working material for mortar and limewash.
Mortar and Limewash Recipes
| Product | Ratio | Use | Notes |
|---|---|---|---|
| Lime mortar | 1 part lime putty : 2.5–3 parts sharp sand | Laying stone and brick | Flexible, breathable — suitable for historic structures; hardens slowly (weeks to months); never use with Portland cement |
| Limewash | 1 part lime putty : 5–8 parts water | Interior/exterior coating, antimicrobial treatment of walls, whitewash | Apply in multiple thin coats. Antimicrobial — kills pathogens on surfaces. Excellent for dairy buildings and latrines. |
| Hydraulic lime mortar | 1 part hydraulic lime : 2.5 parts sand | Below-ground and wet applications (foundations, cisterns) | Sets by chemical reaction (not just drying); works underwater; requires hydraulic lime (NHL) which has clay impurities naturally |
| Cob mortar | Lime + clay subsoil + sand + straw fibers | Cob construction, earthen plaster | Highly plastic; self-leveling; traditional rural construction worldwide |
| Soil stabilization | 5–10% quicklime mixed into soil | Road beds, floor bases | Reacts with clay to produce pozzolanic binding — dramatically increases load-bearing capacity |
Hydraulic Lime vs. Air Lime
Air lime (non-hydraulic): Sets by carbonation — absorbing CO₂ from air. Only works in air; will not set underwater. Takes weeks to months. Remains somewhat flexible.
Hydraulic lime (NHL): Contains silica/alumina compounds (from clay impurities in the limestone). Sets by both carbonation AND hydraulic reaction (with water). Sets faster, stronger, and works in wet conditions and underwater. Identified by the presence of dark "clinker" spots in the burned limestone — these are silica-rich zones.
Roman concrete (Opus Caementicium): The Romans used volcanic ash (pozzolan — from Pozzuoli, Italy) mixed with lime to create a hydraulic concrete of extraordinary durability. The volcanic ash provides reactive silica. Volcanic ash substitutes: pulverized brick, fired clay, blast furnace slag, rice hull ash, or silica-rich wood ash can provide pozzolanic activity. Mix 1 part lime : 1 part pozzolan material : 2 parts aggregate.
7. Adhesives & Sealants
Pine Pitch Glue
Composition: 3 parts pine pitch (resin) : 1 part charcoal powder : 1 part beeswax (or fat).
Process: Melt pitch carefully over low heat (flammable — no open flames if possible; use water bath). Add charcoal and beeswax. Mix thoroughly. Apply hot with stick to surfaces to join. Cures as it cools. Reheat to reposition.
Properties: Waterproof, flexible, bonds stone/wood/bone/ceramic. Used for millennia for arrowheads, tool hafting, canoe sealing, waterproofing containers. Not suitable for high-heat applications.
WaterproofStone/wood/boneArrowhead haftingCanoe sealingHide Glue
Source: Collagen from animal hides, hooves, bones, and cartilage.
Process: Simmer hide scraps, hooves, or bones in water for several hours. Strain out solids; reduce liquid by boiling until thick and sticky. Pour into molds to set into gel. Dry into sheets or granules for storage. Reactivate by dissolving in hot water.
Properties: Strongest wood-to-wood adhesive — woodworkers still use it for furniture. Reversible with heat and moisture (a feature: joints can be disassembled by steaming). Not waterproof. Sets by cooling, not by chemical cure.
Wood joineryFurnitureReversible jointsBookbindingBirch Tar
Process: Distill birch bark in a sealed clay vessel (pack bark tightly, small hole at bottom for drip collection, heat externally). Brown-black oil drips out. This is birch tar. Concentration can be adjusted by further heating. True dry distillation — no water involved.
Properties: Ancient Neanderthal and Stone Age adhesive; antimicrobial; waterproof; black. Used for tool hafting, waterproofing baskets and leather, skin treatment for eczema and psoriasis. Very sticky; difficult to remove from skin (use oil or animal fat to dissolve).
WaterproofAntimicrobialAncient adhesiveLeather treatmentNatural Rubber (Climate Dependent)
Sources: Rubber tree (Hevea brasiliensis) latex — tropical only. Dandelion root latex (Taraxacum spp.) — temperate, lower yield. Guayule (Parthenium argentatum) — semi-arid Southwest USA.
Collection: Score bark of rubber tree at 30° angle, 1.5mm deep; collect dripping latex. Dandelion root: grind roots, collect white latex, allow to coagulate.
Vulcanization (without sulfur): Smoke-vulcanization was used by Amazonian peoples — hold latex over smoky fire to cross-link polymer chains. Produces a more durable, less sticky rubber than raw latex.
Seals/gasketsWaterproofingTropical zones only8. Gunpowder
| Component | Historical Percentage | Function |
|---|---|---|
| Potassium nitrate (saltpeter, KNO₃) | 75% | Oxidizer — provides oxygen for combustion |
| Charcoal (carbon) | 15% | Fuel — fine-ground hardwood charcoal is best |
| Sulfur | 10% | Lowers ignition temperature; improves ignition reliability |
Saltpeter Sourcing — Nitre Beds
Potassium nitrate occurs naturally where organic matter decomposes under specific conditions. Traditional nitre beds were constructed by:
- Building a covered shed over a mixture of: stable manure (high nitrogen), old mortar/limestone rubble (calcium), straw, and soil.
- Keeping moist but not waterlogged. Urine accelerates the process (adds nitrogen).
- Turning the pile regularly to aerate — the nitrification bacteria are aerobic.
- After 12–18 months, white crystals appear on the surface (potassium/calcium nitrate efflorescence).
- Dissolve the bed material in hot water; filter; add wood ash (provides potassium to convert calcium nitrate to potassium nitrate); boil down to crystallize.
- Crystals are filtered, dried, and re-dissolved 2–3 times for purity.
Safety and Handling
- Sensitive to heat, friction, and static electricity. A spark or static discharge from clothing can ignite unconfined powder.
- Mix only small amounts (less than 50g at a time for testing). Never use metal tools — use wood, bone, or plastic.
- Store dry in non-metallic, sealed container. Small quantities only. Never store large quantities.
- Unconfined, it burns rapidly (deflagration) rather than detonating. Confinement is required for projectile propulsion.
- Uses in context: Signal flares and fire starters; primitive firearm propellant; blasting for mining; pyrotechnics for signaling search-and-rescue.
9. Improvised Cleaning & Sanitation Products
Vinegar
Vinegar is dilute acetic acid produced by acetic acid bacteria (Acetobacter) oxidizing ethanol. Any alcoholic liquid can become vinegar.
Uses: Food preservation (pickling), surface cleaning, pH adjustment in soap making, hair rinse (restores pH after alkaline soap), weed killer (undiluted), meat tenderizing, and as a weak disinfectant.
Washing Soda (Sodium Carbonate)
Baking soda (sodium bicarbonate, NaHCO₃) converts to washing soda (sodium carbonate, Na₂CO₃) by heating:
- Spread baking soda on a baking sheet in a thin layer.
- Bake at 200°C (400°F) for 1 hour, stirring occasionally.
- It loses CO₂ and water, converting to washing soda. The texture changes — it looks more crystalline and coarser.
Washing soda is more alkaline (pH ~11) than baking soda (pH ~8.3). Uses: heavy-duty laundry cleaner, dishwasher detergent substitute, degreaser, drain cleaner. Do not use on aluminum — reacts and corrodes.
Bleach — Storage and Limitations
| Storage Factor | Details |
|---|---|
| Shelf life (sealed, dark, cool) | 12–18 months for 5–6% household bleach before significant degradation |
| Shelf life (opened) | 3–6 months before activity drops below effective levels |
| Storage conditions | Sealed, dark container, cool temperature (<25°C). Heat, light, and air accelerate decomposition. |
| Concentration loss | Loses ~20% of activity per year at room temperature even when sealed |
| Test if still active | Pour small amount on concrete — if it bleaches the surface quickly and smells strongly of chlorine, it's still viable |
| Substitute disinfectants | 10% lye solution (caustic — use gloves); 70%+ alcohol; pine tar; boiling; UV exposure (sunlight) |
Lye Solution as Disinfectant and Cleaner
A 10% potassium hydroxide or sodium hydroxide solution in water is an effective surface disinfectant, drain cleaner, and oven cleaner. It is corrosive — use gloves and avoid contact with eyes and skin. Food-grade uses include:
- Pretzels: Brief dip in 3–4% lye solution before baking creates the dark crust and characteristic flavor
- Lutefisk: Fish preserved in lye solution, then rehydrated
- Nixtamalization (corn): Soaking dried corn in 5% lye or slaked lime solution overnight releases niacin (prevents pellagra) and makes amino acids bioavailable. This is critical for corn-dependent communities — communities that adopted corn without nixtamalization (the American South, parts of Europe) suffered widespread pellagra.
- Olive curing: Soaking green olives in dilute lye removes bitter compounds (oleuropein) before brining
10. Chemical Compatibility — What NOT to Mix
| Also Remember | Hazard |
|---|---|
| Never burn plastic for heat near food | Releases dioxins and HCl (from PVC) — carcinogenic, contaminates cooking area |
| Never burn pressure-treated wood indoors | Contains arsenic and chromium — toxic fumes |
| Never use galvanized metal for cooking | Zinc oxide fumes from heated galvanizing cause "metal fume fever" |
| Never store distillate in tin containers | Tin reacts with acid in spirit — produces organotin compounds; use glass only |
| Carbon monoxide from generators/stoves | Odorless, colorless — kills without warning. Never run combustion engines/stoves indoors without ventilation. |