Properly sealed white rice genuinely stores for 25–30 years, but brown rice goes rancid in months. Here is what actually decides shelf life, which storage methods hold up, and where the marketing claims are real versus optimistic.
About 10 years in storage for alkaline AAs, 20 to 25 for lithium, and three to five years of service for a car battery, which can still die in a month if the car sits. Shelf life by chemistry, how to store lithium-ion so it does not age, and a battery plan for an emergency kit.
Six months at minimum and a full year to be safe, until the wood reads under 20 percent moisture. How to split and stack it so it dries faster, the signs that it is ready, and the two-minute moisture meter test that settles it.
The official figure is three years at 80°F. The famous 130-month chart is 1980s data on older rations. Why heat decides almost everything, how to read the time-temperature indicator and date code, and when an old pouch goes in the trash.
Most vegetable seeds stay viable two to five years kept cool and dry, onions and parsnips about one, leeks about six. A crop-by-crop longevity table, how to store seed so it beats the chart, and the ten-seed test that tells you whether old packets are still worth sowing.
The number on the box is one tank of fuel. The real ceiling is oil: a check at every refuel, a change every 100 hours on a portable, and a 30 minute rest every 24 hours on a standby unit. How to keep one running through a ten-day outage instead of a weekend.
Pure salt never spoils. The date on the canister is about the additives: iodine that fades over about five years, and anti-caking agents that eventually give up. Why iodized salt is the one worth rotating when you eat from storage, and how to keep the rest dry forever.
Three to five years cool, under a year in a hot garage, and the twenty-five year figure on the bucket is answering a different question. The research numbers by temperature, why nonfat is the only version that stores, and what changes the moment you add water.
About a year for white flour, one to three months for whole wheat, and the difference is the oil in the germ. What the date on the bag actually means, why the bugs arrived with it, and why a deep pantry stores wheat rather than flour.
Two people can carry the same gear at the same weight and have completely different days. Where the weight sits decides whether your hips carry the load or your back fights it all afternoon.
Two to five years sealed, about a year once opened, and no standards body will give you an official number. What actually ages it, why the grade matters more than the date, and the blue-can rule that keeps gasoline out of your heater.
Every brown line is a walk you could take without going up or down. Learn the contour interval, the index lines, which way the Vs point, and how spacing reads as steepness, and any USGS quad becomes a route you can plan.
Six to twelve months untreated, three to five years done properly, and the difference is almost entirely water. Diesel does not go stale the way gasoline does. It grows something at the bottom of the tank, and by the time you notice, the filters are already gone.
Running watts times 1.25, then check the surge. That is the easy half. The half that decides whether your plan is buildable is on the DC side, where 3,000 watts at 12 volts means 290 amps of cable, and the answer is a higher bank voltage rather than thicker wire.
Square footage gets you a bracket, not an answer. Here is the sizing table, the adjustments almost everyone skips, why oversizing is the expensive mistake on an inverter system, and what the thing actually draws when the grid is down.
One to two years in the box, decades sealed, and the date on the side is not a safety date. What actually ends a box of pasta is moisture, the fat in the egg and whole wheat kinds, or insects that were already in the packaging.
Nearly everyone owns a sharpener, and nearly everyone still has dull knives. The gap is two things: the angle you are actually holding, and the burr you are not feeling for. Stone, rod, pull-through, or the bottom of a coffee mug, it is the same two things every time.
Liters decide what fits. Torso length decides whether the weight lands on your hips or hangs off your shoulders for three days. And for an emergency bag, one number settles the whole argument: three days of stored water weighs 25 pounds.
The propane itself never expires, but the cylinder is certified for only 12 years and the runtime is pure arithmetic. A 20 lb tank is 430,000 BTU. Here is how to turn that into hours for any appliance, and why a cold tank starves a burner that has fuel left in it.
Sealed and dry, it does not spoil at all, and the date on the jar is about flavor rather than safety. The chemistry behind that is worth knowing, because it tells you the one thing that actually ruins honey: water.
Three months untreated, about a year stabilized, and the clock starts at the pump. What actually goes wrong inside the can, why ethanol makes it worse, and the rotation habit that keeps a generator starting on the second pull.
The FDA does not require that date on the bottle and sets no shelf life for water at all. What the date really means, what actually degrades a stored supply, and the garage habit that quietly ruins it.
Annual kilowatt-hours divided by peak sun hours, derated 14 percent. That is the whole calculation, and it lands between 13 and 25 panels depending almost entirely on where you live. Plus the part sales calls skip: grid-tied solar shuts off in a blackout.
Running watts plus the single biggest starting surge. That is the whole formula, and skipping the surge is why a generator that can run your refrigerator still cannot start it. Worked examples from a fridge on its own up to a whole house.
Ferro rod, battery and steel wool, lens, flint and steel, bow drill: what each one is actually good for. Plus the reason most attempts fail, which is never the spark and always the tinder.
Stop trying to heat the house and start heating a person. The room-shrinking, layering, and sleep setup that actually works in a cold house, and the improvised heat sources that kill people every winter.
Four hours in the fridge, 48 in a full freezer, 24 in a half-full one. The USDA numbers that settle the argument, the 40°F rule that decides what gets tossed, and the free prep that doubles your buffer.
Generators are cheap, powerful, and lethal if you place them wrong; solar batteries are silent and fuel-free but weather-limited and pricey. What actually keeps the lights on, from a field engineer who wires both.
Buying one big water drum and forgetting about it is not a water plan, it is a science experiment. What the CDC, FEMA, and EPA actually say about how much to store, when to rotate, and how to treat water when the tap runs dry.
Your phone is a great map right up until the battery dies in the cold or the signal vanishes in a canyon. How to navigate home with a $20 compass and a paper map: declination, bearings, and a weekend drill included.
Most bug-out bags fail for one boring reason: they are too heavy to carry on foot. What ultralight backpackers already figured out, and the leaner list to pack instead.
Pressure, irrigation, and honest limits. What a non-clinician can and can't do responsibly.