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Category: History (Page 1 of 15)


Canned Food is Fine

When I was a kid in the 1950s and 60s, my mother had the opinion that canned food was of low-quality and best avoided. I was young and took her word for it. I maintained this opinion myself into adulthood and sometimes shared it with others. But occasionally I wondered because my own observations and experience didn’t agree. In the late 1990s I became sufficiently curious and learned about it. But first some history.

A Real Short History of Modern Canning

The Dutch Navy were the first to seal foods like salmon in metal cans in 1772. For some reason, this process remained unknown outside of the Netherlands.

The rest of the story begins with French military logistics. In 1795, Napoleon offered a large reward to anyone who could develop a way to preserve foods so that armies could have better provisions when deployed, especially in summer temperatures. As you may know, logistics is what wins wars and availability of food was a major limiting factor in what armies could do.

Fifteen years later, Nicolas Appert won Napoleon’s prize after observing that food cooked inside a sealed jar did not spoil. The reason for this was unknown for another 50 years until Pasteur identified the role of microbes in the spoilage of food. The army worked on developing this process but advancement was slow and the wars were over before useful quantities could be produced.

Development of the canning process continued in Europe and the U.S.A. A process was developed for canning foods in hand-made wrought-iron cans, which worked. But the process was labor intensive and expensive. In 1824, Parry took canned beef along on his voyage to the Arctic. In 1829, James Ross took canned food to the Arctic as did John Franklin in 1845. Some of these provisions were found in 1857. One can was opened in 1939 and found to be edible and nutritious but was not tested for lead contamination from the lead solder used to make those cans.

By the mid-1800s, the wealthy began to see canned foods as a status symbol and novelty. By the 1860s, rising urban populations increased demand for canned food. Many inventions and machines were developed to fabricate cans rapidly. Improved processing methods reduced cooking time from six hours to 30 minutes.

Skipping ahead, a big step was the invention of the double-seam can in 1888. These provided a reliable perfect seal and were called Sanitary Cans. This is the type of can we use today. By World War 1, mass production of canned goods was perfected and large quantities of food, coffee, cigarettes, medications, and ammunition were packaged for the soldiers in cans by the British, French, and the U.S.A. At the end of the war, the companies equipped to make such foods like Nestle and Underwood turned to selling to the general public. Canned foods proliferated. It was now possible for European made foods to be sold in the U.S. and vice versa. Canned tomatoes and canned peaches were available year-round, regardless of the season. It was a whole new world.

Expiration Dates and Safety

I’m old so while I now expect expiration dates on foods, it still seems like a new thing for me. I remember when milk started to bear a date, then eggs, then meat. Before that you could write your own date with a grease pencil if you wanted to. And these were manufacturing or packaging dates, not expiration, best by, or use by dates. Food manufacturers soon realized that by putting “use by” dates on everything they could force supermarkets and consumers to donate or discard food that was past the date and sell a lot more product. Very quickly, manufacturers were all-in on putting dates. Customers began to expect dates.

Today, everything has a date. Even bottled water has a date and many consumers think dates are required by law. They are not. The only things in the U.S.A. required to have a date are pharmaceuticals and baby formula.

When use-by dates began to appear on cans, I just laughed. Cans are hermetically sealed and then heated to sterilization temperature or higher, as high as 130C. Most items are cooked in the sealed can itself. There’s no chance for microbial contamination unless the can leaks.

Modern double seam cans like we’ve used for the past 100 years almost never leak. When they do it’s usually visible. If a can isn’t damaged or bulging and passes the appearance and smell tests, it’s safe to eat.

In the 1970s, a trove of cans of freeze-dried food from 1865 was discovered and tested1. There was no trace of microbial contamination and the food was safe to eat. In the 2000s a trove of cans of various foods from the Depression Era (1930s) was discovered which were sent to a food lab for analysis. All of it was safe to eat. The worst case of degradation was the canned corn, which had lost 30 percent of its nutrient value, but was safe to eat.

Do canned foods last 20 years? USDA says “Most shelf-stable foods are safe indefinitely.”

Back to My Mother

In short, my mom’s opinion about canned food was false. But why did she have this opinion? Thinking back on the stories she told me as I was growing up provided the answer. My mom grew up in a big city in Northern Germany in the 1910s and 20s. By the 1920s, a lot of the food on the table was canned because that’s all that was available. Her mother was an early health-food proponent and went to great lengths to seek out fresh fruits and vegetables, gather wild berries and mushrooms. This made an impression on my mother.

When my mom came to the United States in the 1930s, she was astonished at the abundant fresh foods available in markets everywhere, even in big cities. And like most immigrants, she had the idea that everything was better in the U.S.A., which led to her deprecation of canned foods as inferior.


The truth is it’s not a matter of inferior or superior, it’s a matter of cooked versus fresh. If you want raw or lightly steamed broccoli, that’s not going to happen with a can. On the other hand, the can of broccoli will be there waiting for you years into the future without power-consuming refrigeration or freezers. Canned foods tend to be cheaper not because they’re lower quality but because it’s usually prepared near the farm, doesn’t need refrigerated transport, and doesn’t have to be rushed to the market before it spoils. There’s also less waste that has to be refrigerated and rushed to the market. How much of a broccoli head’s mass amd volume do you actually use? A third? The rest goes in the trash but you paid for all of it to come to you fresh.

If you consider the can itself, it’s made of steel, which is cheap, abundant, and non-polluting in a landfill. Unlike plastics, steel is easily recycled but hardly anyone does because steel is so cheap. If you look at the big picture, canned foods make a lot of sense.

General Sherman’s Prophetic Letter

General William Tecumseh Sherman is an important name from the U.S. Civil War. He was a distinguished military man and master of military strategy. Sherman was also a successful author, teacher, and businessman. When General Grant became president in 1869, Sherman succeeded him as Commanding General of the U.S. Army.

Sherman was born and raised in Ohio, but had many friends in the Southern States and enjoyed being there. In fact, he was in Texas when South Carolina seceded from United States. He was so upset by this event that he cried and wrote the following letter to his friend, Professor David F. Boyd in Virginia, who was strongly in favor of secession. The letter proved to be an accurate analysis of the situation and visionary forecast of the final outcome.

General William Tecumseh Sherman, U.S. National Archives

He wrote:

“You people of the South don’t know what you are doing. This country will be drenched in blood, and God only knows how it will end. It is all folly, madness, a crime against civilization!

You people speak so lightly of war; you don’t know what you’re talking about. War is a terrible thing! You mistake, too, the people of the North. They are a peaceable people but an earnest people, and they will fight, too. They are not going to let this country be destroyed without a mighty effort to save it.”

“Besides, where are your men and appliances of war to contend against them? The North can make a steam engine, locomotive, or railway car; hardly a yard of cloth or pair of shoes can you make. You are rushing into war with one of the most powerful, ingeniously mechanical, and determined people on Earth — right at your doors.

You are bound to fail. Only in your spirit and determination are you prepared for war. In all else you are totally unprepared, with a bad cause to start with. At first you will make headway, but as your limited resources begin to fail, shut out from the markets of Europe as you will be, your cause will begin to wane. If your people will but stop and think, they must see in the end that you will surely fail.”

A Brief History of Birthday Celebrations

The celebration of birthdays is common and taken for granted today. But for common, ordinary people this is a relatively recent phenomenon, a product of the Industrial Age. There are several reasons for this.

The Egyptians

There are instances of birthdays being celebrated since ancient times, but mainly by important people. The oldest known birthday celebrations took place in Egypt about 5,000 years ago. When a prince was made pharaoh, that moment was considered the transformation of a man into a god and was considered his “birthday”.

The Ancient Greeks

The ancient Greeks observed birthdays, not as a celebration, but because they believed that a spirit is present when each person is born, and that this same spirit was nearby around the same time each year. They also believed that a person was susceptible to evil spirits around the time of their birthday. Family and friends would gather and light candles to ward off the darkness, and make loud noises to frighten off evil spirits. Dates were not precise by modern standards because an accurate calendar had not yet been invented in Europe.

Birthday Celebration for Commoners

The Romans were the first to create holidays to honor famous persons, usually around the approximate date of their birth. The Romans were the first to create a birthday celebration for commoners. When a Roman man reached the age of 50, he was honored with a cake made with cheese and honey. Birthdays of women were ignored for another thousand years.

Birthday Celebrations Prohibited

For hundreds of years, the early Church frowned on the observance of birthdays. It was seen as a pagan practice, something done by pharaohs and heathens. Birthday celebrations were considered evil. Needless to say, the birth of Christ wasn’t celebrated either. Nobody knew the date anyway. From the information in the Bible one can guess it was during tax time in the Roman Empire, which was in the spring.

Common folk found this prohibition easy to abide by. Most didn’t know their date of birth. Common people didn’t have access to calendars and the modern Gregorian Calendar wouldn’t be invented for another thousand years. If a person was baptized, the Church would sometimes record the date, but such dates were approximate, like “the second week of harvest AD 532”. Nobody celebrated their date of baptism. Birthdays were just not a thing.

Creation of Christmas

The Church’s ban on birthdays came to an abrupt end when it was decided to celebrate the birth of Jesus coincident with the ancient pagan celebration of Saturnalia.1

The plan was to use the existing celebration of Saturnalia to recruit people into the Church. This is how the date for Christmas was chosen.

Modern Birthday Cakes

Turning the clock forward 1,300 years, the Germans came up with the idea of celebrating children’s birthdays with a birthday cake decorated with one candle for each year of life.2

This celebration, Kinderfeste, was only for young children. The idea of blowing out the candles and making a wish appeared at the same time.

The Industrial Revolution

Another 50 years brings us to the Industrial Revolution in the mid-1800s, about 160 years ago. Several things happened that resulted in the popularity of birthday celebrations for all ages.

The most important change was that people began to have fewer children. Children were seen less as an economically valuable army of working hands and more as emotionally valued members of the family. More attention and emotional energy was invested in each child. Celebration of birthdays became important.

Before this time, the price of the materials needed to make birthday cakes, like sugar and butter, were expensive. Fancy cakes were something for the well-off. The Industrial Age brought prices down and birthday cakes became affordable.

Previously rare clocks and printed calendars became affordable and commonplace. People became more focused on time and dates because in the Industrial Age people worked shifts and needed to know the date and time to be at work. Education improved and common people learned to tell time and read calendars. People knew their birth dates. Doctors started to record the age of patients as an important parameter. Schools began to group students by ages. All of these changes and much more came very rapidly over a period of just 40 years.

Together, all of the factors above resulted in widespread celebration of birthdays that continues today. Some people resisted, arguing that celebration of birthdays was self-centered, materialistic, and took attention away from God. But this didn’t become an important point of view.


Fun Fact: The Greeks were the first to put candles on a cake, but it wasn’t to celebrate birthdays. A crescent shaped cake was made and decorated with candles to honor the goddess of the hunt, Artemis, who was closely associated with the Moon. Blowing out the candles while making a wish was seen as sending a prayer to Artemis.

Our Favorite Things are Aldehydes

Aldehydes and Allergies

Aldehydes are so common and important in our lives that it’s good to know something about them. The flavor of vanilla, almond, cinnamon, and many others result from aldehydes. Aldehydes are a family of chemicals that are common in nature and foods, and important in industry. I knew that artificial vanilla and almond flavorings posed little danger to people with nut allergies. But the question came up in a discussion and I decided to find out if what I knew was, in fact, correct. (It is.) In the process of researching this, I fell down a rabbit hole of fascinating information, learned a number of interesting things related to chemistry and food chemistry, and collected it here in this article.

There is a family of chemicals called aldehydes that are extremely useful to plants and industry. It’s called a “family” because aldehydes have a common core molecular structure with an open bond to which various molecules can be attached that give various effects.

Three common aldehydes

One thing aldehydes have in common is strong and distinctive odors. Another characteristic of aldehydes is that most of them are toxic in sufficient concentration. (Concentration is key here. At low concentrations, most of them are harmless.) I expect you are already familiar with or have heard of several of the aldehydes I’ll mention.


The one I’ll mention first is not closely related to foods but is one you’ve almost certainly heard of. Formaldehyde1 is a critically important chemical in many industries including plastics manufacturing, fibers, and adhesives. Some of the best and strongest waterproof glues are based on formaldehyde. Formaldehyde is a disinfectant and is used to preserve biological specimens. In biology class you may have seen specimens or body parts preserved in jars. Those were likely filled with formaldehyde as a preservative. Formaldehyde is toxic2 and carcinogenic in sufficient concentration. It’s produced in small amounts by most organisms, including humans.

You’ve all smelled it. It’s a key ingredient in “new car smell”, “new carpet smell”, and “newly constructed house smell”. Our noses are sensitive to aldehydes so very low concentrations are detectable.


The next one is acetaldehyde.3 This one is produced by plants and occurs in bread, coffee, and ripe or overripe fruit, and is a component in the fragrance of wine and the smell of smoke. Acetaldehyde4 is formed from the oxidation of ethanol. It forms in the bloodstream after drinking alcohol and is partly responsible for hangovers.


Plants discovered the value of aldehydes a long time ago. When nature discovers a chemical that provides two unrelated benefits for the price of one, it’s a definite keeper. Aldehydes are such chemicals. Some of the most important flavors in foods result from aldehydes.


Vanillin5 is a member of the benzaldehyde family of aldehydes and is the chemical responsible for the flavor and fragrance of vanilla. It makes the seed pod of the vanilla orchid attractive to birds and animals and is an insecticide. Two functions for the price of one. Unlike most aldehydes, vanillin has low toxicity and is classed as merely an irritant.6

Vanilla has been in use in the Americas for at least 4,000 years. It was brought to Europe by Spanish explorers in the 1500s.


The odor and flavor of cinnamon comes from an aldehyde that’s found in the bark of the cinnamon tree and various others where it serves as an insecticide. Cinnamaldehyde7 is a pale viscous liquid that functions as an anti-bacterial, anti-fungal, and is a potent repellent and killer of Aedes mosquitos. Like vanillin, cinnamaldehyde has low toxicity and is classed as merely an irritant.8

At high humidity and temperature, cinnamaldehyde decomposes to styrene. This is why cinnamon always contains a small amount of styrene.


This is the aldehyde that gives almonds their flavor.

It also occurs in certain fruits and the pits of peaches, apricots, apples, and cherries. It makes the fruit more attractive to animals and is an insecticide. It’s frequently used by bee keepers as a bee repellent. The odor causes bees to leave the hive while honey is collected after which they return to the hive.

Benzaldehyde is the simplest of all the aldehydes consisting of a benzene ring attached to the open bond of the aldehyde molecule. Benzaldehyde is classed as an irritant.10


Vanillin, cinnamaldehyde, and benzaldehyde are chemically classed as merely irritants. Technically all three are toxic in sufficient concentration, but so is water. To reach dangerous levels you’d have to consume absurdly large amounts. In the case of almond extract, you’d die of alcohol poisoning long before reaching dangerous levels of benzaldehyde.

The key here is concentration. Human noses are quite sensitive to aldehydes so for flavoring only a tiny amount is needed. Since most kitchens lack the ability to measure microgram quantities, these extracts are heavily diluted with alcohol so useful amounts can be measured with a teaspoon. At levels used for food flavoring there is some evidence these compounds provide anticarcinogenic effects.11

These aldehydes can all be synthesized in the laboratory or made inexpensively at industrial scale. There is no difference between vanillin made by an orchid and chemically produced vanillin. The same is true for benzaldehyde. If anything, the synthetic version gives a purer more consistent flavor note because it’s pure and not complicated by myriad other chemicals that vary from plant to plant.


The flavor of cilantro derives from several substances, some of which are aldehydes. Some people perceive the flavor of cilantro as a refreshing lemony-lime but some perceive it as tasting like soap or something rotten. It was found that 80 percent of identical twins had the same perception of cilantro but only 50 percent of fraternal twins did. This implied a genetic cause. Today the gene(s)12 have been identified. It’s believed that those who like cilantro are unable to detect one or more of the aldehydes in cilantro.


Furfural is an aldehyde that results from the dehydration of sugars. It occurs in agricultural by-products like corncobs, oat bran, oat hulls, wheat bran, and sugarcane bagasse. It’s a common ingredient in processed foods and beverages. It commonly appears in many cooked or heated foods.

Furfural13 is classed as acutely toxic, an irritant, and health hazard.14

It’s dangerous to the skin. NIOSH permissible level is 5 ppm. 100 ppm is considered an immediate danger. Furfural is lethal to rats and dogs at concentrations of 200 to 1000 ppm. It’s flammable and explosive when mixed with air. It has a penetrating odor reminiscent of almonds. There is no data on human subjects.


The importance of aldehydes cannot be overstated. Retinaldehyde15 is found in meats and is the chemical basis of our eye’s ability to sense light. Another name for it is Vitamin A aldehyde. Vertebrates acquire it directly from eating meat or can also synthesize it from carotenoids. In higher concentrations it’s classed as an irritant and a health hazard.16


This aldehyde is believed to play an important role in the formation of the chemical building blocks of life.17

Interestingly, radio astronomy has detected glycolaldehyde in interstellar space. It’s also been identified in Comet Lovejoy, along with ethanol. This aldehyde is classed as an irritant, highly reactive, and is a common metabolite produced by living things ranging from bacteria to humans.

Lily Aldehyde / Lysmeral / Lilial

Lily aldehyde18 has a strong floral odor reminiscent of lily of the valley. Thousands of tons are produced each year for use in perfumes and detergents.

It’s classed as a health hazard,19 found to be harmful to fertility, and is banned in the EU since March 2022.


If you’ve made it this far in this article, you can probably guess from the name that citral20 is the aldehyde primarily responsible for the fragrance of citrus fruits like lemon, lime, etc.

Citral is found to have a pheromonal effect on acari and insects. Chemically, it’s classified as an irritant.21

It’s a component in the oils of several plants, as follows.

Lemon myrtle (90–98%)
Litsea citrata (90%)
Litsea cubeba (70–85%)
Lemongrass (65–85%)
Lemon tea-tree (70–80%)
Ocimum gratissimum (66.5%)
Lindera citriodora (about 65%)
Calypranthes parriculata (about 62%)
Australian ginger (51-71%)
Petitgrain (36%)
Lemon verbena (30–35%)
Lemon ironbark (26%)
Lemon balm (11%)
Lime (6–9%)
Lemon (2–5%)


Citronellal is the aldehyde that gives citronella its lemony scent. Citronella22 is an insect repellent. Research has shown it to be highly effective at repelling mosquitos and is a strong antifungal.

Chemically, it’s classed as corrosive, an irritant, a health hazard, and environmental hazard.23


Lastly, we come to allergies, specifically allergies to benzaldehyde or vanillin. It’s possible for a human to develop an allergy to almost anything, even metals like nickel. The good news is that it’s rare for someone to be allergic to these two aldehydes that are such important flavors.

The vast majority of allergies, whether it’s to pollen, animal dander, fish, shellfish, bee stings, whatever, are allergic reactions to proteins found in those things.

Natural almond extract is made by steaming almonds in a pressurized vat, then extracting the almond oil. This liquid includes not just benzaldehyde but many other chemicals including proteins. These proteins are usually what a person with a nut allergy reacts to. Genuine vanilla also contains many chemicals from the plant besides vanillin.

Artificial almond extract consists of a small amount of synthetic benzaldehyde diluted with ethanol. Neither has been anywhere near an almond tree and it contains no proteins or anything else. The same is true for artificial vanilla.

The concentration is chosen to match the flavoring power of genuine almond or genuine vanilla extract so the artificial is interchangeable with the genuine in recipes.

Fortunately, this means that those with nut allergies are almost sure to be safe with artificial almond or vanilla flavoring. Even so, if you have a nut allergy, especially a bad case, you should check with your doctor / allergist. They will be able to specifically test whether you are allergic to benzaldehyde (unlikely) or to the dozens of other compounds in nuts.

As a final note, a significant number of children and adults test positive for allergy to cilantro but only a few exhibit symptoms. For those who do, the symptoms can be severe.

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