There are compensations of being cooped up indoors in wintertime. Bilbo Baggins looked forward to the long evenings in his hole at Bag End when he could relax in an armchair toasting his feet in front of a blazing fire. It’s a time of greater idleness and harder to rouse oneself even for a few steps from a comfort zone to the pantry for a snack. And bee colonies are likewise.
As the outside temperature falls below freezing, they huddle deep inside their hive to maintain a remarkable 90 °F. (32°C.). The workers who labored so hard on warm days earlier in the year are now idlers that rarely bother to snack, and no longer share their precious honey stores with drones that died off in the fall. The queen is at the quiet center of the bee-ball. She has stopped laying eggs, and won’t resume until February when the colony must expand rapidly for the coming nectar flow.
Honey stores gradually run down over the cold season. On warm days, a few workers head out to forage for the few hours before sundown, but it is a risky business because if nectar and pollen are scarce the flights may have a negative energy balance. Bee colonies often perish from starvation at the end of winter, just a few days or weeks before food is plentiful again.
The beekeeper who stole most of the honey hoarded last summer must replace it. Trading sugar for honey seems good to him. But the sugar-water that was welcome in warmer months needs lots of energy from beating wings to evaporate it, and can increase the danger of condensation inside the hive. So we give candy to the bees, and why not at Christmas?
On a warm Christmas Day like today there was no danger of chilling the bee-ball when I lifted the inner cover to check the girls. I took a bar of candy out of Santa’s sack and rested it on the frames of empty honeycomb. The candy was home-made by boiling concentrated sugar with a few drops of essential oils until it caramelized and set into solid bars. It’s toffee for bees. A few lethargic workers crawled from their warm place to inspect the treat. Last year, I tested whether they could tell the difference between refined sugar and non-caloric artificial sweetener, because some people find it difficult. Of course bees aren’t so easily fooled. They know that real sugar is vital for survival, but it’s a different story for our species.
Smoke curling out of an open window or from under a car hood is a bad omen, and smoky chimneys and cigarettes emit toxins. It often means bad news, and we made a metaphor of it, There’s no smoke without fire. But occasionally it seems almost wholesome.
I used to enjoy it gently billowing over a wok before I threw vegetables on the hot oil to stir-fry. Perhaps smoke from cooking is welcome because the kitchen is a sanus sanctuarium— provided the oil doesn’t catch fire! I wonder if different notions about smoke rarely cross-fertilize because they are processed in separate registers on the right and left sides of my brain. No doubt there’s a lot more mental subtlety involved, but one day when smoke from a wok on the kitchen hob made me cough my right brain woke up to ask why. Wasn’t it a healthy smoke? And, if not, what kind of chemical brew was I creating?
It’s a question that has been studied more by biological chemists than you might think from the few media reports, although some food warriors have posted smoke signals. When I started reading tidbits from scientific journals I understood why.
When any kind of vegetable oil is heated a chain reaction starts to evolve aldehydes like acrolein, 4-hydroxynonenal, and a bevy of other unfamiliar molecules. Heated above the ‘smoke point,’ the rates of reactive aldehyde formation climb ever higher. Some of these molecules are known mutagens that can form adducts with DNA, making them candidate carcinogens. Polyunsaturated fatty acids in oils recommended by the authorities are more vulnerable to oxidation than the monounsaturated types because they have more double bonds. Saturated fat, which by definition have none of them, are much more stable. Suddenly, it dawned on me that home cooking can make my home more polluted than the street at rush hour.
If vapor was the sole danger I could avoid it by turning up the extractor fan, but my meal was bathing in a toxic slush. Since higher temperatures and long cooking times increase the problem, I wondered how many times cooking oil is re-used at the fast food joint where I sometimes buy a burger and fries? I also thought about my neighbor who saves oil from his deep fryer after cooking a Christmas turkey? Perhaps it’s safer dining at home.
Restaurant chains can reduce oil oxidation under a blanket of non-reactive nitrogen, or at least test the quality of any reused oil, but home cooks don’t have that option until there is a mass spectrometer for the kitchen countertop. Meantime, we blithely follow recipes regardless of chemistry, and have to rely on our senses and common sense for safe cooking.
The first precaution is to watch for smoke, which is a warning that the oil has spoiled and should be replaced. The second is to sniff over the pan because an acrid smell points to acrolein in the vapor. And the final test is to taste the oil.
When I compared several cooking oils by heating them to 400 °F. (204 °C.), the extra virgin olive oil and walnut oil were smoking before they reached this temperature, and their fruity notes were gone and tasted bitter. These oils had already gone bad. But refined oils like canola had higher smoke points, and though they started tasteless they remained that way. Lastly, I opened a large bottle of olive oil which had just passed its sell-by date. Since it smelled rancid, oxidation was happening at room temperature and, reluctantly, it had to go. Vegetable oils are a kitchen doctor’s dilemma that Mum never had to worry about. How did it happen?
As heart disease grew to epidemic proportions, the American nutritionist, Ancel Keys, led a charge against saturated animal fat over fifty years ago. He was followed by an omnibus of researchers, medical societies, and government officials who transformed the national diet which we still have (but I won’t say enjoy). The arguments were based on apparently unassailable reason and facts—energy-rich fat makes us fat, and dietary cholesterol deposits in atheromatous plaques. Clinical surveys (occasionally) helped to prove the low fat revolution was sound.
But when animal fats were thrown out of the diet the food industry had to fill the gap. Where would the missing calories come from, and what would replace the fat needed as shortening for pastries, cookies, etc? The industry turned to vegetable oils rich in polyunsaturated fats. This decision seemed a safe bet, especially because they were already marketed as margarines created by chemical conversion of liquid oils to partially hydrogenated trans fats. These products had the dual virtues of remaining solid at room temperature (like butter) and having a high smoke point for deep-frying (like lard or beef tallow). As the demand for more vegetable oils bloomed, farmers sowed fields with ever larger crops of rapeseed and soybean. However the safety of trans fats was not sufficiently scrutinized until recently when were they banned in restaurants, food labeling was mandated and the F.D.A. posted a health warning. The complex mixture of unnatural isomers in trans fats are implicated in a wide range of diseases, and now it’s their turn to be condemned.
The food industry is reluctant to return to animal fat because of the legacy of research stretching back to Dr. Keys and the stamp of officialdom. Although a search for substitutes continues, refined vegetable oils have found a new role in deep frying. They are presented as a healthy choice because they don’t raise the ‘bad’ type of cholesterol (LDL), although a rather weak predictor of heart disease in most people. You seldom read about the downside.
The public continues to be subjected to a vast dietary experiment that fails to conquer cardiovascular disease, which still beats cancer to the top of the C.D.C. list of causes of mortality. Switching from animal fat to trans fat and from trans fat to refined vegetable oils have been hailed, in turn, as advances in public health, but we may have ended up with a new cancer risk, or at least a concern that deserves more research. Moreover, as dietary calories from fat have declined over the years they have been replaced by refined carbohydrates, which are now held responsible for obesity and diabetes emerging in children. It’s hard to grasp the scale of disease, disability, and death that can be traced back to dietary recommendations over the last two generations.
I hope people are thinking more about their diet, and listening less to official prescriptions. The relationship between our food and health is far more complicated than the experts were wont to believe. I hope that people fret less about fat in their diet than about the environment in which crops are grown and farm animals are husbanded. There are far too many vested interests in our food choices. Mum’s cooking probably wasn’t as unhealthy as the next generation assumed when they squirmed at the larded memory. I’m sure her pastry, cakes, and cookies tasted better than those served today.
I have turned the tables on cooking fats and oils at home. Margarine and polyunsaturated spreads are out, butter is in. Butter can be good even at high temperatures if the solids and water are removed by clarification. And if lard ever reappears on supermarket shelves I may pull out one of Mum’s old recipes.
For high temperature cooking, I often use refined oils, like safflower, which have high smoke points; olive oil and tasty nut oils are reserved for salad dressing and other cool uses. The pros and cons of different oils otherwise confuse me because the composition of healthy fatty acids (usually meaning omega-3s) and antioxidants vary with the source, season, and storage conditions. Of course, we choose those that taste best (the unprocessed kinds), but I am more focused now on safe cooking to avoid nasty radicals generated by oxidation. And I am more careful about storage conditions, meaning for shorter periods in the cool and dark. I even squeeze drops of vitamin E from capsules into bottles of vegetable oil to help preserve them.
These concerns about dietary fats are new to me, though they shouldn’t be. As long ago as the late 1950s, Denham Harman (1916-2014), a gerontologist at the University of Nebraska, was expressing doubts about the wholesale adoption of vegetable oils in the national diet. As a former chemist at Shell Oil, he knew that unsaturated fats are unstable and susceptible to oxidation. In one of my books published in the 1990s (Cheating Time), I mentioned his free radical theory of how oxidized lipids cause cell aging and disease. But the penny didn’t drop in a lifetime of cooking until I leaned over a smoky wok one day.
[In coming weeks I will post about sugar and salt]
For kids growing up in London during the austere decade after WWII, it was a special treat to be taken to the zoo by parents or school teachers. The zoos were crowded. Children had to be hoisted on the shoulders of grown-ups to see the big cats pacing in their cages, and catch the eye of Guy the gorilla across the moat. We had no guilty feelings then about their cramped quarters, because we assumed the animals were there for our entertainment. Nor did we learn much about their wild nature or the habitats from which they were taken. We thought it would be cool to be zookeepers pushing joints of meat under the bars for tigers, tossing herrings for sea lions to catch, and locking our school ma’am in the reptile house at the close of day. But, in hindsight, there wasn’t much difference between the zoo and Wormwood Scrubs prison, except for the species incarcerated.
There were no parklands for those animals to roam, except outside London at Whipsnade. But zoos have come a long way. The naturalist and author, Gerald Durrell (1925-1995), was regarded by the Establishment in those days as a maverick for calling on zoos to change into centers for captive breeding of endangered species instead of being public exhibitions of unhappy creatures. As is the way of pioneers, he is now celebrated as a visionary and memorialized at the Durrell Wildlife Park for conservation, but there was one thing he never changed. You still had to go to his zoo to see animals.
One of our master naturalist friends, Clyde, is also a zookeeper, but not the kind I ever imagined. He was more radical than Durrell when he created a portable zoo that could be taken to children in their classrooms and to public parks. The critters were collected in his neighborhood or the local churchyard under state collection and exhibition permits. Reptiles and amphibians were returned to where they were caught a few days earlier, while other creatures were cared for at home. His zoo is transported in shopping bags in his car trunk and, although none of the big predators and venomous snakes beloved by children can be included, his small critters have been tremendous hits. Since it was launched in 2007, he has entertained and educated over 13,000 children and adults across five school districts in south-east Virginia.
The mission of this zoo is education instead of conservation. Clyde was concerned that most children are less connected with nature nowadays than when he was growing up. Few of them grow up on farms or want to visit city zoos or are allowed to roam the countryside unsupervised, and their days are brimful of organized activities and screen time. The writer, George Monbiot, worries that, Without a feel for the texture and function of the natural world, without an intensity of engagement almost impossible in the absence of early experience, people will not devote their lives to its protection.
We can hope the newly-minted generation will be more caring about the environment than their predecessors, but I think the chances are much greater for those who have met Clyde and seen his menagerie. Watching how they respond to his lessons warms our hearts, the lower grades 2 through 5 especially. When Clyde and his “zoo cru” of helpers transfer critters from Tupperware boxes and glass jars to trays on the front desk, there is plenty shuffling as boys and girls strain to identify the collection of beasts—beetles and butterflies, mantises and millipedes, slugs and snails, salamanders and skinks, toads and turtles. There are a few skins, scales and shells for creatures that are too rare or too dangerous for live ones to be let loose. The boldest kid steps forward to ask if a giant hissing cockroach could rest on his sleeve. Even those who stood nervously behind the front row eventually want to tickle a roly-poly or poke the leaf litter to make a centipede scurry. Giggles and questions go in circles like whirligigs. Some questions from minds full of innocent curiosity are disarmingly penetrating.
Clyde explains that every species has its own life history, then tells their stories. One of his favorites is about the community that lives under logs, where he finds many of his critters. He asks the class what they expect to find when they roll a log over. A short arm shoots up with an answer, usually its “beetles” or “spiders.” He then spins nine yards of ecology, and I doubt any other lesson that day captures more attention.
Leaning forward to the class, he tells them dark secrets about beetles. They feed on the wood rotting on the underside of the log. He shows them a little bag containing brown, granular material. “It’s beetle poop,” he confides (more giggles). “It will be made into healthy soil particles by tiny things called decomposers.” But life under the log is not all rosy. There are predators just as voracious as on the African plain. Beetles, slugs, and spiders are eaten by salamanders, frogs and toads, and occasionally a long black racer winds under the log to gobble all of them up. “After we looked under the log, we must roll it back,” he tells them. “We have to care for nature because all things are connected, including ourselves.”
Clyde loves to quote the wisdom of American Indians, but it was Rachel Carson who expressed his role, If a child is to keep alive his inborn sense of wonder … he needs the companionship of at least one adult who can share it, rediscovering with him the joy, excitement and mystery of the world we live in.
Most children in this district only have one opportunity to see his zoo, so you might wonder if they will remember his stories in the future. Surely, their memories will gradually sink in their unconscious minds and become overlaid with hosts of new stories and experiences. But they won’t die. I think they will linger underground, maybe for years or even decades, like fungal hyphae which, when fertilized by soil, season, and time, will suddenly sprout above ground into the light as toadstools full of fruitful spores.
Clyde is now a retired zookeeper, but others are continuing his mission.