⚗️Chemistry ⚗️
Thomas Salter's Flagship Chemistry 7
When I was 8 years old, I had my first chemistry set.
Many of the experiments in the manual included a lot of chemicals available in the kitchen. That was also where I conducted my experiments because of the kitchen table and the sink.
It included Kosher salt (NaCl), sugar (C₁₂H₂₂O₁₁), baking soda (NaHCO3), vinegar, caustic soda (NaOH), Epsom salt (MgSO₄ 7H₂O), citric acid (E330), coffee filters, etc.
Hexagonal Honeycomb Periodic Table
The first periodic table to become generally accepted was that of the Russian chemist Dmitri Mendeleev in 1869; he formulated the periodic law as a dependence of chemical properties on atomic mass.
I am going to focus on: Na, Mg, K, Ca, Cu, Fe, F, Al, Zn, Au, Hg, N, P, Si, Br, S, Cl, Se, I, etc. Some for nutrition, some for metals commonly used in kitchenware and their physical properties.
Biochemistry
Pickling vs. Fermentation
Pickling vs. fermentation – what's the difference and what can you ferment?
Fermented foods have become popular for their potential health benefits, while pickling has long been used as an easy way to preserve food. But what exactly is the difference between the two methods – and why is fermentation often touted as the healthier choice?
Both pickling and fermentation extend the shelf life of foods, but they work in very different ways. Pickling often involves vinegar and sugar, while fermentation is a natural fermentation process where beneficial bacteria convert carbohydrates into lactic acid. Here the differences between pickling and fermentation are explained.
Pickling: A Quick Preservation Method
Pickling is a process in which vegetables (or fruit) are stored in an acidic liquid – typically vinegar, often with added sugar, salt and spices. The acid creates an environment that inhibits bacterial growth and extends the shelf life of the food.
Advantages of pickling
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Quick process – vegetables are ready in a few hours or days
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Extends shelf life for months
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The taste becomes sour and fresh due to the vinegar
Disadvantages of pickling
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Contains no live bacteria as vinegar kills microorganisms, and is therefore not beneficial for digestion
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Can be high in sugar and salt, especially in ready-made products
Examples of pickled foods
Pickled cucumbers pickled red onions, pickled beets, pickles, chutney.
Fermentation: A Natural Fermentation Process
Fermentation is a biological process in which naturally occurring bacteria and yeast convert carbohydrates into lactic acid, alcohol, or acetic acid.
Unlike pickling, fermentation does not use vinegar but allows lactic acid bacteria to grow naturally. This process creates a sour taste and adds beneficial probiotic bacteria that can support the intestinal flora.
Benefits of fermentation
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Contains live probiotic bacteria that can benefit the colon flora
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Provides a deeper and more complex flavor than pickling
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May increase the bioavailability of nutrients
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Long-lasting, but requires refrigerated storage
Disadvantages of fermentation
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Can take several days or weeks to complete
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Improper fermentation can result in mold or unwanted flavors
Examples of Fermented Foods
Sauerkraut (fermented cabbage), Kimchi (spicy fermented Chinese cabbage), lactic acid fermented cucumbers, Kombucha (fermented tea), Kefir (fermented milk), Miso and tempeh (fermented soy products).
What vegetables can be fermented?
Almost all vegetables can be fermented, but some are better suited than others.
1. Cabbage and leafy greens
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White cabbage: Used for sauerkraut
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Chinese cabbage: The main ingredient in kimchi
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Kale and spinach: Can be fermented, but requires a good brine
2. Root Vegetables
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Carrots: Retain their crispness and gain a slightly sour taste
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Beets: Often used in fermented beetroot juice or sliced in brine
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Parsnips and parsley roots: Gain a mildly sour taste
3. Red Onion and Garlic
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Red Onion: Fermented for a softer and sweeter flavor
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Garlic: Can be fermented alone or in combination with other vegetables
4. Cucumbers and other fruit-bearing vegetables
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Gherkins: Can be fermented and become lactic acid-fermented pickles
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Tomatoes: Small tomatoes can be fermented whole in a light brine
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Peppers and chilies: Used in fermented hot sauce
5. Legumes and Sprouts
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Soybeans: Used for miso and natto
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Chickpeas and lentils: Can be fermented and used in spreads or soups
6. Mushrooms and exotic vegetables
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Mushrooms and Shiitake: Can be fermented in brine, but rarely used
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Lotus root: Used in certain Asian fermentation methods
Which vegetables are less suitable?
Vegetables with a high-water content, such as lettuce and cucumber, can become too soft if fermented without the support of other vegetables.
Potatoes and other starchy root vegetables tend to become slimy and are rarely recommended for fermentation.
Should you choose pickling or fermentation?
If you simply want to extend the shelf life of your vegetables, pickling is a quick and easy solution. If, on the other hand, you want to add more probiotic bacteria to your diet, fermentation may be a good choice. Both methods have their advantages – and the best part is that you don’t have to choose.
Remember, you can also combine them in your cooking and enjoy both the fresh pickled taste and the gut-friendly bacteria from fermented foods.
For more information on autolysis and fermentation of dough
see the pizza section.
Oxidation
Redox reactions
Scorzonera is a root vegetable that is often called "winter asparagus" because its consistency and cooking uses are similar to green asparagus. When peeled, they oxidize quickly and turn brown in contact with the oxygen in the air, so they are peeled in a bowl of water with a few slices of sour lemon.
Preservation
There are two key factors that inflict the conservation of food. One is water and the other is contact with air.
Sodium vs. Potassium
Osmose/Osmosis
Preservation
There is no such thing as something you can just smear on anything and be germ-free, because different bacteria have different levels of resistance to different things. Salt will kill some things and not others, and the bacteria that normally live on your skin are already resistant to elevated salt concentrations because they have to survive your sweat.
First of all, it doesn't matter what % NaCl it is until you dissolve it in water. The maximum concentration of NaCl in water you can get at room temperature is ~36% by weight (or 6.3 M).
Second, even if you rubbed a 36% w/w aqueous solution of NaCl into your skin, you wouldn't be germ-free. It wouldn't do anything to kill viruses, for example. And some of the bacteria on your skin, in addition to being salt-resistant to begin with, would be hidden between your dead skin cells, where your rinsing wouldn't reach them. (This is one reason soap is useful: it reduces the surface tension of water, making it easier for water to get into smaller cracks.)
Sure, you could peel your skin off first, but a) at that point you don't need a saltwater cleanse, and b) the saltwater cleanse would kill your own cells without skin to protect them.
If you're referring to its use in food preservation, it's more bacteriostatic than anything else. In brine, it acts as a desiccant to limit the free moisture that bacteria can use to multiply, as well as drawing water out of bacterial cells through osmosis at higher salt levels.
Achieving the same thing on your skin probably wouldn't end well. Your skin would have to have a high enough salt content to dehydrate your epidermis, which relies on moisture, and would allow bacteria to penetrate the fluids in your dermis and multiply there.
There was a reason why it was politically mandated to add iodine to conventional salt, even though it has a metallic aftertaste. Common diseases such as goiter and dwarfism can be attributed to iodine deficiency. Subsequently, Kosher salt without added iodine came into the picture.
Blood pressure vs. Pulse rate
Blood pressure is the pressure of the blood against the walls of the blood vessels, while pulse is the
number of heart beats per minute.
Blood pressure shows how hard the heart is working and is given as two numbers.
The first number is the highest systolic pressure, and the last number is the lowest diastolic pressure.
Pulse is a measure of the heart's speed and is given as the number of beats per minute (e.g. 60-80 at rest).
Sodium/Potassium regulates those values.
All of this becomes very important if you're looking into survival cooking.
An increased intake of potassium increases blood pressure/heart rate and thus increases pressure on the colon.
So, if you have problems with hard stools, increase your intake of potassium.
100g of raw vegetables or 600g of cooked vegetables per day is recommended.
Salt
Everything about salt
Sorts of Salt
Maldon Salt is a premium, hand-harvested sea salt produced in Maldon, Essex, England, since 1882. Renowned for its unique, pyramid-shaped crystals and crunchy texture, it is used as a finishing salt to add a clean, delicate, and savory flavor to dishes without overwhelming them.
Freezing Point
Salt lowers the freezing point of water through a process called freezing point depression. By dissolving into ions (Na⁺ and Cl⁻), salt disrupts the ability of water molecules to bond and form a solid crystalline structure (ice), meaning the water must be colder than 0°C (32°F) to freeze.
Triple Point
The triple point of water is the very specific combination of temperature and pressure at which water exists simultaneously as solid ice, liquid water, and vapor in thermodynamic equilibrium. This occurs at exactly 0.01°C (273.16 K) and a pressure of 611.657 pascals (approx. 0.006 atm).
Sugar
Maillard reaction
Adding a little sugar to a steak while it's cooking can help caramelize the crust, so also when caramelizing onions.
For sweet desserts, it is more important to serve the dessert cold, as warm is interpreted as being too sweet.
Sugar is added to ice cream to prevent the formation of ice crystals. Too much sugar takes longer time to freeze.
The Maillard effect is a chemical reaction between amino acids residues and reducing sugars that leads to the formation of melanoidins, contributing to the distinct flavor and brown color of foods and reducing sugars in the egg white when exposed to high heat. This process creates melanoidins, which are responsible for the brown color and nutty flavor.
It commonly occurs when frying at high temperatures or in fat like butter or oil.
The Maillard reaction is a fundamental, non-enzymatic chemical process between amino acids and reducing sugars that occurs when food is heated, typically between 140 and 165 °C (280–330 °F). It produces brown pigments called melanoidins and hundreds of flavor compounds, creating the savory crust on steaks, roasted coffee, bread, and fried foods.
Ice Cream
Glucose (dextrose) lowers the freezing point of ice cream more effectively than regular sugar (sucrose), resulting in a softer, creamier texture.
Glucose/Dextrose/Dextrose: Are the same (monosaccharides). They are less sweet than regular sugar but have a greater ability to lower the freezing point. This prevents the formation of large ice crystals, resulting in a silky-smooth ice cream.
Regular sugar (sucrose): Is a disaccharide. It is sweeter but has a less freezing point lowering effect compared to glucose.
Glucose syrup: Used to add body and prevent crystallization and is less sweet than sugar.
Calcium
Vitamin-D
Calcium absorption is not working optimally in the bloodstream.
Calcium increases blood pressure by constriction of blood vessels, Magnesium decreases it.
Milk
Introduction
Whole milk is generally considered best for preparing hot meals.
However, lactose-free milk often has a longer shelf life when unopened because it is highly pasteurized and therefore contains fewer bacteria. However, once opened, it is more susceptible to bacteria and should be stored in the refrigerator, where it typically lasts 7-10 days, unlike regular milk, which has a shorter shelf life after opening.
Unopened
Longer shelf life: Higher pasteurization temperatures kill more bacteria, giving lactose-free milk a longer shelf life. Storage: Shelf life can be up to 1-2 months when stored in a cool, dark place, but always check the date on the package.
Opened
Shorter shelf life: The milk's content of lactic acid bacteria, which normally protects against other bacteria, is lower in lactose-free milk due to the high pasteurization. Once opened, the shelf life typically lasts 7-10 days in the refrigerator if stored correctly at a max. of 5°C/40°F.
Lifestyles
Chemistry
5 A Day
Aim for at least five portions of a variety of fruits and vegetables each day, with one adult portion being about 80g.
This "5 A Day" campaign is based on World Health Organization (WHO) advice to reduce the risk of serious health problems like heart disease, stroke, and certain cancers. Benefits also include maintaining a healthy weight, supporting eye health, and reducing inflammation.
What counts as a portion?
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Fresh, frozen, or canned: 80g of fruit or vegetables is one portion.
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Dried fruit: 30g is one portion (limit intake due to high sugar content).
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100% fruit/vegetable juice and smoothies: A maximum of 150ml counts as one portion per day. This is because it's higher in sugar than whole fruit and can cause tooth decay.
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For children: A portion is roughly the amount they can fit in their palm, and a variety of colors is recommended.
Examples of portion sizes
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A medium-sized apple, banana, or orange
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A handful of berries or grapes
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A large slice of melon
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One cup of leafy greens (raw) or half a cup (cooked)
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Five to eight broccoli florets
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A medium carrot
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Half a large bell pepper
Prediabetes
Prediabetes is a condition where your blood sugar is elevated, but not high enough to be diagnosed with type 2 diabetes, and it can often be reversed through lifestyle changes such as diet, exercise, and weight loss. Without changes, prediabetes increases your risk of developing type 2 diabetes, heart disease, and stroke. It is important to get your blood sugar checked, as there are typically no obvious symptoms of prediabetes.
Vegetarian vs. Vegan
Vegetarianism excludes meat, fish, and seafood, but may include dairy products and eggs, while veganism is a stricter form that excludes all animal products and by-products from the diet, including dairy, eggs, and sometimes honey, and can also extend to avoid animal-derived materials like leather. Both can be healthy with proper planning, but vegans must pay closer attention to ensure they get enough vitamin B12, calcium, and vitamin D.
Pescetarian
Pescetarianism is a diet that excludes land animals and poultry but includes fish, seafood, and other animal products like eggs and dairy. The term is a portmanteau of the Italian word pesce (fish) and vegetarian. Reasons for choosing this diet include potential health benefits, such as increased omega-3 fatty acids from fish, and environmental concerns about the impact of meat production.
Keto
Keto refers to the ketogenic diet, a low-carbohydrate, high-fat eating plan that shifts the body's primary fuel source from carbs to fat, inducing a metabolic state called ketosis. In ketosis, the liver produces ketones.
Ketones are acids the body produces when it converts fat into energy instead of glucose from carbohydrates. This typically happens during fasting, a low-carb diet, or when there is too little insulin. While normal levels of ketones are harmless, too many can lead to a life-threatening condition called ketoacidosis, especially in people with diabetes.
Ketones become the main energy source for the body and brain when glucose is scarce. This diet significantly reduces carbs, often to 20-50 grams per day and replaces them with fats and moderate protein, leading to potential benefits like rapid weight loss, improved blood sugar control, and a boost in energy.
How it works
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Carbohydrate restriction
The core of the keto diet is a drastic reduction in carbohydrate intake, limiting foods like grains, fruits, and starchy vegetables.
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Ketosis
With very few carbs to burn, the body enters ketosis, a state where it turns fat into ketones for energy.
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Fat for fuel
Instead of glucose, the body and brain primarily use these fat-derived ketones as their main fuel source.
Key characteristics
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High fat
The majority of daily calories (around 70-80%) come from fat.
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Moderate protein
Protein intake is kept moderate to avoid conversion to glucose, which would hinder ketosis.
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Low carbohydrate
Typically, carbohydrate intake is kept below 50 grams per day.
Potential benefits
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Weight loss
The diet can lead to significant short-term weight loss.
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Blood sugar control
It can cause massive reductions in blood sugar and insulin levels.
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Mental clarity and energy
Some people report enhanced mental focus and increased energy levels.
Considerations
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Initial side effects
You may experience initial symptoms like fatigue, headaches, and brain fog as the body adapts.
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Nutrient deficiencies
A varied diet is essential to avoid deficiencies in fiber and other nutrients.
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Medical supervision
It is advisable to consult a doctor or registered dietitian before starting, especially for those with underlying health conditions.