Chemical Engineering in Daily Life – Question 30: How do North American Indians make maple syrup? Standard answer already available
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This post was last edited by yjqin1 on 2015-9-24 at 20:07. People of Chinese descent in North America, especially in Canada, usually bring American ginseng and various health supplements when they return to their home country. The more fashionable ones will also bring some maple syrup back as a gift for relatives and friends. Maple syrup is useful for eating toast and drinking coffee; don’t people often say they’re pretentious? Have you ever eaten toast dipped in maple syrup? The year before last, I took the children to a nearby Native American tribe to learn how to make maple syrup. Everything is primitive: small buckets made from bark, a pile of stones for heating, a stone basin used as a pot, a stone awl for drilling holes in maple trees, a wooden tube to draw out the sap from the maple trees, as well as some stone basins and bowls, wooden shacks, wooden tables, wooden chairs, and wooden bowls. In short, there were no iron tools, no metal utensils. They poured the extracted tree sap from small buckets into the stone pot, and added hot stones heated by fire into the pot; this caused the water to boil, thereby concentrating the maple syrup. Please note that the initial sugar concentration is only around 2–3%, whereas the sugar concentration in regular commercial maple syrup is 30–40%. A few years ago, while waiting for a connection at Toronto Airport and having some free time, I wanted to buy some maple syrup to take back home as a gift. While wandering around, I happened to run into an old classmate from the department of mechanics, whom I had met during my doctoral studies in 1988; it had been over 20 years since we last saw each other. Thank you, maple syrup! During harsh winters when food was scarce, Indians could survive by drinking tree sap. Question 1: The maple trees used to produce sap are so thick that two people are needed to hold them together. Why then do they make only three holes the thickness of a pencil in each tree, and why is only one hole used at a time to extract the sap? Question 2: Why don’t the maple trees in China produce sap? Question 3: Why do maple trees in Canada and the United States produce syrup when they have nothing better to do? Again, try to consider things from the perspective of chemical engineering as much as possible.
Teacher, your question is a bit too intense; it’s better to take things slowly over time – that’s how a better series can be created
If too much is applied at once, it will kill the maple tree; to use it over the long term. Maple syrup is the energy reserve of maple trees. It may be related to living conditions. It also attracts animals for pollination.
Are maple leaves sweet? This issue has not been considered before.
Speaking of something off-topic, maple syrup is actually made from the sap that comes from maple trees; I thought it was made from the nectar of maple trees. When I was a child at home, we ate the nectar of birch trees – it was golden in color and very sweet
Standard answer: Question 1: The maple trees used to produce sap are so thick that two people are needed to hold them together. Then why do they make only three holes the thickness of a pencil in each tree, and why is only one hole used at a time to extract the sap? Answer: The view from the third floor: If too much is applied at once, it will kill the maple tree; it’s necessary to use it in moderation for long-term use. That’s the case, but people in this country generally don’t think that way. Question 2: Why don’t the maple trees in China produce sap? Indeed, Chinese maples do not produce sap. In regions with distinct seasons, some of the energy stored in woody plants is present in the roots in the form of starch or sugar. When the weather is cold, this sugar is transported back from the roots to the stems and dry parts under the action of capillaries, where it oxidizes slowly, thereby releasing heat and keeping the plant’s temperature slightly higher than that of the surrounding air. Or are Chinese maples more cold-resistant and do not need this feature? But I think: mainly in North America, there is still a lot of precipitation in winter, and the groundwater level is high; local maple trees make full use of this condition. In northern China, precipitation occurs mainly in summer, with the amount of precipitation throughout winter being less than 10%, or even 5%, of that in the United States and Canada at the same latitudes. So, over millions of years, the local maples have evolved to this extent. What I still don’t understand is: how can capillary force be strong enough to lift a dilute sugar solution dozens of meters up inside a tree trunk? However, if the capillaries within the bark are thin enough and have sufficient hydrophilicity, it is possible according to the Kelvin equation or the Laplace-Young equation. Question 3: Why do maple trees in Canada and the United States produce syrup when they have nothing better to do? In autumn, maple trees store part of their energy in the roots in the form of starch or sugar. When the weather is cold, this sugar is transported back from the roots to the trunk, stems, and branches through the capillaries, where it oxidizes slowly, releasing heat that raises the temperature inside the maple tree slightly above that of the surrounding air. Maple trees have survived for millions of years in the cold regions of North America in this very way. Around 10,000 to 30,000 years ago, Indians who arrived in North America from Asia via the Bering Land Bridge accidentally discovered that broken maple trees contained a liquid that flowed out; when they tasted it, they found it sweet, so they began to suck the maple sap. At first, it was interesting and satisfying, but during times of scarcity it became a means of survival.
I learned it! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !