How freeze-drying leaves food with less than 4% of its original water content

Partial freezing results from trying to freeze water while preventing expansion

Within a sealed container, partial freezing of water increases the contained volume and the pressure, preventing further freezing without decreasing the temperature further. Once cooled below -23 degrees Celsius (-9.4 degrees Fahrenheit), an uncommon type of ice that contracts as it forms is produced, facilitating the complete freezing of the contained water.

The benefits of sous vide: cooking food in bags immersed in water

Through this technique, food can be prepared to precise temperatures lower than those of open flames, without the risk of overcooking, with less oil, fat, and salt, and without requiring ongoing attention. By allowing for long cooking times, tougher cuts of meat can also be prepared at lower temperatures.

Freezer burn is the result of moisture leaving ice cream

The ice cream death knell occurs when water crystals melt and then refreeze on the surface of the treat, creating a crunchy (but far from delectable) shell. The best way to prevent this unfortunate outcome is by storing your ice cream in a freezer that’s colder than 0°F.

What is freezing fog?

Freezing fog is a weather condition in which fog containing supercooled water freezes on contact with objects, forming a layer of ice and possibly dangerous driving conditions. Get the breakdown with this explainer.

Explaining the Leidenfrost effect, where water can hover and move against gravity

Water droplets can glide across surfaces whose temperatures are well above water's boiling point. This heat instantly vaporizes the bottom of the droplet, creating a layer of steam that the rest of the droplet rides and bounces upon. This can be seen when sprinkling water on skillets to determine if the surface is hot enough to cook on.

The boiling temperature of water decreases with increasing elevation because the molecules need less energy to overcome the lower atmospheric pressure associated with thinner air.

A guide to making ice cream with liquid nitrogen by flash-freezing dairy

Only existing in liquid form at extremely low temperatures, nitrogen can rapidly freeze cream, coconut milk, and other liquids into small crystals, producing smooth, creamy ice cream. As a safety precaution, liquid nitrogen should be handled in a well-ventilated area with safety goggles and protective gloves.

The boiling temperature of water decreases with increasing elevation because the molecules need less energy to overcome the lower atmospheric pressure associated with thinner air.

The food processing techniques developed for World War II, later repurposed for consumers

Research projects funded or sponsored by the military led to the development of active dry yeast to make bread easier to bake and an improved version of dehydrated cheese, which would be used in powdered cheese snacks. Freeze-drying, which had been used to ease the transport of blood plasma to battlefields, where it would be reconstituted with water, was later used on fruit for cereals.

The industrial methods for recovering helium, including filters and cryogenic separation

Membranes with microscopic pores of varying sizes can be used to selectively filter out components of natural gas, including helium, which can then be concentrated. Because helium requires the lowest temperature of all elements to condense into a liquid, extracted natural gas can also be cooled until only helium remains as a gas.

Water vapor is used to manage heat in high-end smartphones

While smartphones have traditionally been cooled using a highly conductive plate that dissipates heat from the chip, vapor chambers offer a higher heat-removal capacity. This technology has been utilized in laptops for decades to absorb heat by cycling a fluid between liquid and gaseous phases.

Explaining concentrate and how concentrate-derived juice differs from its source

Developed to reduce the volume of goods—thus lowering storage and shipping costs—the concentration process uses pressure and heat to remove water, pulp, and skin from fruits. Concentrates provide significant flavor, sugar, and calories to foods in small quantities, but do not retain most of the fiber, vitamins, and other nutrients from the source fruit.

What makes food crispy, and how science can be used to maximize this property

The fracturing texture experienced when biting into vegetable tempura, fried chicken, pastry crusts, and other foods comes from having a dehydrated, porous surface. When frying food in hot oil, trapped water vaporizes and escapes, creating tunnels and pores in the food as it dehydrates. Breading, particularly with the large, irregular shapes of panko, and leaveners can help create more air spaces.

Muted smell and taste in microgravity complicate meal enjoyment

Astronauts primarily consume freeze-dried meals, which are rehydrated with water recycled from urine and perspiration, directly from bags. Condiments and select cultural items from crew members can enhance the meal experience by boosting flavor. Many individuals report experiencing "food fatigue" due to a lack of fresh produce, limited menu variety, and lingering scents.

Tardigrades can survive in a dehydrated state for decades

Despite being known as water bears, these microscopic creatures can shut down their metabolism when entering cryptobiosis, squeezing more than 95% of the water from their bodies. In this tun state, tardigrades can even survive the vacuum of space.

The history of many kitchen appliances involves unexpected discoveries and applications, including wartime radar turned hamster defroster and replacing an 'ice king' with heat-stealing boxes.

Desalination involves costly, energy-intensive methods for producing freshwater

Thermal desalination heats saltwater to produce steam, and reverse osmosis forces saltwater through a membrane that only allows water through. In both cases, freshwater is collected and remineralized for consumption, while wastewater brine is often returned to the ocean, where it may harm marine organisms.

Light can be used to slow the motion of atoms

While photons possess energy, they also have momentum, which allows them to collide with other particles, much like billiard balls, thereby slowing them down and reducing their kinetic energy, or temperature. Using multiple lasers from different directions, particles can be cooled to within one degree of absolute zero.

Health workers may cool body temperatures with convection cooling

That's spraying a patient with water and putting fans over them. Cooling the body by removing clothing and placing cold water and ice packs—and not blocking evaporation—are essential cooling steps.

To reduce wrinkles in clothing, research recommends gentle wash cycles with more water and tumble drying with smaller loads and longer times.

To reduce wrinkles in clothing, research recommends gentle wash cycles with more water and tumble drying with smaller loads and longer times.

How disgorgement works while making sparkling wine

After riddling, winemakers still need to dispose of collected sediment in wines. While this was once done by hand, the modern method of freezing the bottle's neck and removing the now-solid sediment is ubiquitous. In this short video, an enologist (wine expert) from California’s Halter Ranch vineyards explains each step of the mechanical disgorgement process, complete with footage from their production line.

IVF procedures fertilize eggs outside the body in a laboratory dish

In vitro fertilization is a complex and expensive set of procedures that potential parents dealing with infertility or genetic disorders may turn to when other methods are unavailable. IVF births account for 2% to 3% of all live births in the US annually.

How trees transport water from roots to leaves

Trees move water to their extremities via a deft system starting from the roots to the leaves. See how it works in this short video breaking down the process in a Douglas fir.

Why bean leaves are an effective bedbug pesticide

No one wants a bedbug infestation because getting rid of them is infamously difficult. High heat and diatomaceous earth are two of the most effective bedbug pesticides, but there's another, obscure method: bean leaves! Watch this four-minute video...

Greenhouse gas removal consists of a series of techniques to capture and store GHGs

These include turning biomass into charcoal for storage in soil before it decays and releases carbon dioxide, crushing CO₂-absorbing rocks—increasing exposed surface area—and spreading them across land to accelerate GHG uptake, and restoring degraded peatlands, which can store twice the amount of carbon as the average forest.

Stevia is a plant-derived sweetener but the plant isn't approved for eating

Steviol glycosides, the sweet-tasting stuff in the plant leaves, are purified and highly processed before they end up in the food or drinks sold in stores. The US Food and Drug Administration does not allow the use of stevia leaf or crude stevia extracts in food, and the agency also bars them from being imported into the US for use as sweeteners.

The stages of fasting

What happens to the body when it goes without caloric intake? This article overviews the immediate physical effects of fasting. Within a day of going without food, the body will have used up its glucose stores and ordered the liver and muscles to convert their glycogen (glucose storage) into usable glucose. By the second day, glycogen stores will run out, forcing the body to use fat as energy. This process is known as ketosis.

Scientists can determine Earth's past climate conditions by analyzing air trapped in microscopic bubbles within ice cores—columns of compressed snow layers that build up over hundreds of thousands of years.

Against his wishes, Albert Einstein's brain was removed before his cremation, and the pathologist responsible stored it for decades in mason jars within a beer cooler.

The use of fungi to detoxify land and water—a process known as mycoremediation—has been used to clean up natural resources affected by the 2025 California wildfires.

At the beginning of the 20th century, a group of young men ate standard American food—replete with food additives like borax and formaldehyde—as part of government research to better understand food safety.

Learn how your body is, scientifically, like a firework with its own slow, controlled burn.

Pure water does not conduct electricity because this flow of energy requires the movement of charged particles, and water is a neutral molecule.

Objects can be 3D printed with light by projecting 2D computerized tomography (CT) scans onto rotating cylinders of resin, which solidify upon exposure.

Budweiser stores yeast derived from the original 1800s strain in a secret bunker, which only the Head of Yeast Management can access—not even the CEO

The price of gas is a composite made up of several different factors, with the federal gas tax making up less than 20% of what drivers pay at the pump.

Apollo astronauts left items in the moon's 'toss zone,' including golf balls, family photos, and bags of human waste, to make room for lunar rocks.

Doctors differentiate between a phobia and fear by asking patients whether their fear interferes with their day-to-day activities.

Ebola is a filovirus, meaning it resembles a thread under a microscope, though it sometimes twists and can resemble a bowl of spaghetti.

Venture capital is a form of funding provided to early-stage companies with high growth potential, typically in exchange for an equity (or ownership) stake

The Great Salt Lake's distinct dual coloration results from high-salinity organisms that only live in the northern portion and produce a purple protein.

Telehealth demand for GLP-1s for weight loss is booming as consumers seek easier access.

Gerrymandering works through two techniques: cracking opposing voters across districts to dilute their power, and packing them into a few to waste their votes in lopsided majorities.

In 1945, Surrealist artist Salvador Dalí and legendary animator Walt Disney began collaborating on a short film that was not completed until 2003, years after both men had died.

Most of the observable universe's volume consists of voids and supervoids—enormous regions of space with little to no galaxies, stars, or light.

The 1987 Nintendo video game 'Stadium Events' isn't known for being particularly fun, but its scarcity has made it a highly sought-after item that has sold for up to $35K at auction.

For centuries, Niagara Falls has been a magnet for daredevils seeking to conquer one of nature's most powerful wonders, with its 200-foot drop and water rushing at 32 feet per second with 280 tons of force.

Indefinite cloning of some endangered species may not sustain their longevity because cloning success rates decrease as genetic mutations accumulate.

The United States is one of only around two dozen countries with a fully federal system of government, in which power is divided between national and state governments.