Hello everyone! Today I’ll be talking about the future of our food: how humans are trying to come up with alternative food sources to sustain our food supply and ensure food security in the world.

In week 9, we had a tutorial where each one of us in our project group had to pick and read one reading out of the four readings that were available. At the start of the tutorial, we were split into our “specialists” groups to discuss about the reading and after which, we went back to the project groups to share with one another what our readings was about. This way, each person only has to read one reading but would be able to get information from all four different readings!! Yay.

In my case, I read the article called: The meat of affliction. Initially when I read the article, I assumed it would probably just be about the usual kinds of meat we are consuming in our daily lives, how unsustainable the practices to produce all these meat actually are etc. But shortly into the reading, I found out that this article is actually about entomophagy, which is the eating of insects!

This article talks about how insects are actually full of nutrients and proteins and should be considered a very viable alternative source of food, not only in times of crisis.

The view that Western people typically have is that they will never in their lives treat insects as real food and consume them willingly, unless there is really no other choice. Only at the verge of starvation would they consider the consumption of insects.

Personally, I actually would want to try eating insects (but only those that are handled properly though!! :’)) but only for the sake of novelty, to know how these insects actually taste like. If someone told me that I had to eat a bowl of insects for breakfast/lunch/dinner I probably wouldn’t be able to take it. Hence, I understand where people are coming from. It’s a huge step for most people.

However, the article also mentioned ways that could overcome this problem such as improvements in marketing and packaging of these insects. When consumers do not see the insect as a whole, they become slightly more willing to give these insect-based food a shot. Hence, disguising these insects and maybe grinding them up into powder and shaping them into other kinds of food may be helpful in getting people to get used to the consumption of insects? If they didn’t know that it was made from insects they would probably just think that it tastes like chicken or something lolol.

Jumping from the food we consume now straight to insects may be too drastic, so alternatives such as plant-based food are actually getting more popular. Many plant-based food such as the Impossible patty has proven themselves to be just as delicious as their meat-based counterparts and could very likely be the main source of food for humans in the future.

For more technological alternatives, we have the 3D printing of food, which is a very interesting and novel idea. The possibilities for 3D printing is endless. We could print ready-made food, such as 3D printed gummies that are currently already available in the market, or 3D print uncooked food such as pizza from the raw ingredients before cooking it using conventional methods like baking. Alternatively, we could 3D print the food using the raw ingredients and cook it at the same time using heat from lasers. With more research being done in this area, 3D printed food may also be a possible food source in the future.

From all these readings, it can be seen that tackling food security issues may be a handful. We need to ensure we do not starve, but also ensure that our practices are sustainable and not damaging to the earth. Some viable food sources such as insects may not be pleasant to consumers as of now but who knows if their mentalities would change in the future.

That’s all for this post. Thank you for reading!

Hello everyone! Today I’ll be sharing on ice cream and chocolate!

In week 7 we had a workshop on Chocolate and Sorbet, held by Professor Linda Sellou. In this workshop, we learnt a little about molecular gastronomy, the science behind chocolate and ice-cream and even had a hands-on experience on making Chocolate Chantilly, as well as Ribena Sorbet! Let’s start by talking about the Chocolate Chantilly.

Chocolate

Chocolate Chantilly is a mousse/foam-like chocolate dessert that was invented by the father of molecular gastronomy – Hervé This.

To make the Chocolate Chantilly, we only require 2 ingredients: chocolate and hot water! We have to first melt the chocolate in hot water completely, before placing the melted chocolate over another larger bowl containing ice to cool the chocolate down. While cooling the melted chocolate, we continuously whisk the melted chocolate in order to achieve the desired mousse texture.

Initially, when I saw the steps involved, I thought that we will just be re-solidifying the melted chocolate and it seemed pretty pointless to me. But that was because I didn’t understand the science behind the whisking. Whisking the liquefied chocolate is actually the most important step involved in making the Chantilly! What whisking does is that it introduces air into the liquefied chocolate, which is considered to be an emulsion.

Emulsion refers to a mixture of oil and water. Oil and water have different chemical properties which makes them immiscible in each other and when mixed together, they tend to separate into two different layers. However, the addition of emulsifiers may help to solve this problem as these emulsifier molecules position themselves at the oil-water boundary to make sure separation between the 2 layers does not occur.

Chocolate contains oil (in the form of cocoa butter) and an emulsifier (soy lecithin). When hot water is added, the combination of water and oil leads to the formation of an emulsion. The air cells introduced by whisking gets coated by oil particles and when it is cooled, the oil solidifies into fats and traps the air within it. These tiny pockets of air trapped in the mixture leads to an airy, mousse-like Chantilly.

The chocolate our group used was from the brand Chocolat Stella and it’s a dark chocolate made with 100% cacao.

Not sure why our Chantilly did not end up looking like a mousse… maybe too little water was used? But anyway, one word of advice if anybody wants to try this out: please don’t use chocolate with 100% cacao!!!! It was so bitter and one of our classmates actually gagged after trying our Chantilly LOLOLOLOL. Nevertheless, it was still a fun experience!!

I consume chocolate very often but have never really thought much about the process of obtaining it. Through the readings, I’ve learnt a lot more about chocolate. Here are some of the things that I’ve learnt:

• Most chocolates contain cocoa butter, cocoa powder, sugar and vanilla. In the case of milk chocolate, there is the addition of milk powder.
• White chocolate is made up of mainly cocoa butter and it is white because it does not contain polyphenols and cocoa liquor, which give chocolates their distinct taste. Hence, some people do not consider white chocolate to be a form of chocolate.
• Cocoa liquor is the paste from roasted beans and is widely considered to be the heart of chocolate due to the many compounds present which gives rise to the flavor of chocolate.
• Polyphenols, particularly flavanols, are responsible for the health benefits of chocolate. Such compounds have anti-oxidant properties and can help to combat cancer, lower blood pressure and prevent heart diseases. The higher the cacao content in the chocolate, the greater the anti-oxidant properties. This is why dark chocolate is considered to be healthier than other forms of chocolate.
• Phenylethylamine, a molecule that stimulates release of dopamine and norepinephrine molecules which give rise to positive emotions, could be found in trace amount in chocolate. This is why people assume that the consumption of chocolate tends to lift our spirits. However, the phenylethylamine actually gets metabolized very quickly in the body, leaving it with insufficient time to have any effects on our brains.
• Compounds like caffeine and theobromine contributes to bitterness in cocoa beans.
• To produce chocolate, cacao beans have to first be fermented and roasted. While roasting, the Maillard reaction occurs since the beans contain amino acids, peptides, sugars and carbohydrates.
• There are 6 different crystal forms of chocolate and only type V is desired in a chocolate bar. To achieve type V crystals, tempering has to be done. Tempering of the chocolate allows the finished product to have a nice gloss, snap and taste. It also prevents “fat blooming” – where cocoa butter fats re-solidify, causing a gray-ish film to form on the product.

Ice cream

Besides the Chocolate Chantilly, we also had a go at making our own Ribena Sorbet! This is even simpler than the chantilly, all we had to do was pour the ribena juice into a bowl, add a few tablespoonfuls of food grade (!!) dry ice and just keep stirring until all the dry ice sublimes.

The making of ice cream/sorbet is actually a thermodynamic process of releasing heat energy from food. Dry ice is added to cool the liquid down rapidly by allowing the heat energy to be transferred over to itself, causing it to sublime into gas. As the liquid cools, the molecules in the liquid start to re-arrange themselves into orderly positions, leading to the formation of solids. Stirring of the liquid is important for a uniform suspension and to ensure that no large chunks of ice crystals are formed.

This was our group’s final product and it honestly tasted really good!! I was very tempted to make sorbet on my own at home after this but Ziquan said that they only sold the food grade dry ice in 5kg packs 🙁 don’t think I will ever need 5kg of dry ice… LOL

Moving on to what I’ve learnt from the readings about ice cream:

• Ice cream is a complex and multi-phase emulsion since it consists of fats dispersed in water in 2 different phases – solid and liquid.
• The 5 basic ingredients of ice cream are: ice, fats, sweetener, air and other solids.
• Ice crystals are formed when water freezes at temperatures below its melting point. Ice crystals make up the body of the ice cream, giving it its structure. However, the size of the ice crystals formed is crucial as it determines how smooth the ice cream will be. Smaller ice crystal sizes are preferred since large ice crystals gives the ice cream a grainy mouthfeel.
• Fats are typically obtained by using milk or cream. Apart from imparting richness and flavor to the ice cream, fats also improves the texture of the ice cream since higher proportion of fats means less proportion of water and that decreases the chance of formation of large ice crystals. However, a very high proportion of fats in ice cream is also not desirable because the resultant ice cream would taste less refreshing to us. This is because the thermal capacity of water is much larger than for fats and water has a greater ability to draw heat away from our tongue, giving us the cold and refreshing sensation.
• Sweeteners are used not only to impart sweetness to the ice cream, but also helps in modifying the ice cream’s texture.  When sweeteners are added, the freezing point decreases and this ensures that the ice cream does not freeze solid. If no sweetener is added, the ice cream mix would freeze into a rock hard solid and it would be difficult to scrape. If too much of it was added, the mix would not sufficiently freeze and would still exist as a liquid.
• Air helps to build volume in the ice cream, altering its texture. The word “over-run” is used to describe how much air is incorporated into the ice cream and ice cream with higher over-run is more airy and has less content per unit volume.
• Other solids that could be added includes proteins, mineral salts or toppings. Addition of other solids may prevent formation of large ice crystals but would also affect the texture of the ice cream.
• The creation of a good tub of ice cream all boils down to balance between the different components found in the mix.

After the readings for this chapter, I realised how I’ve always taken a bar of chocolate or a bowl of ice cream for granted. I’ve never really thought about the science behind it but with all these new knowledge, I think that I’ll be able to better appreciate the effort behind the chocolate/ ice cream that I consume.

That is all for this chapter, thank you for reading!

Hello everyone! Today’s topic would be on baking and cooking, something that I’m pretty excited to share about!

This may come as a surprise to many (considering how undomesticated I look) but I was actually immensely interested in baking and cooking a few years ago. In my free time, I’ll always be on Youtube watching Laura in the Kitchen, a cooking channel where the host, Laura, shares “simple” recipes with her viewers. There was something really satisfying about watching her effortlessly whip up amazing looking dishes and since she made it look so easy, I thought I could do the same too. I mean, I just had to follow what she did in her video step by step and I will definitely end up with the same mouth-watering dish too right? Apparently not.

I remember the first time I tried following her chocolate chip cookie recipe, back in 2012 or so. The recipe seemed relatively easy to follow: cream together the butter and sugars (white and brown), add eggs, vanilla extract and mix before adding in the dry ingredients such as flour, salt, baking soda and chocolate chips. After giving everything a good stir, scoop the cookie dough onto the baking sheet and send it into the oven where all the magic happens, or at least was supposed to happen.

But no magic happened and I got slapped back to reality. All I remember was me looking into the oven in absolute horror as I watched my cookies “melt” (?), merge with one another and then inflate (not in a good way). When I took it out of the oven, it looked like a huge sheet of spongy bread which was really really really weird considering how they were supposed to be cookies….? Safe to say, no one else in my family dared to try this bread-looking-cookie thing I created but I did try it and honestly (totally not biased at all), it tasted quite okay!!

Even after this bread-cookie misadventure I did still continue to bake (wow talk about resilience) and the next few times I was actually able to produce decent looking bakes, even though I must say that tastewise everything I made was really average. Not great but here are some of the things I baked back in 2012!

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Considering the fact that it was done by a 14 year old, I guess it’s passable….?

Anyway, this passion of mine soon died down because no one wanted to eat what I’ve baked and I had to finish everything on my own LOL (:-(((() And also, I realised that I digressed a lot. Let’s just get to the main point of this blogpost now shall we.

Pancake making workshop

In week 5, we had a pancake making workshop in school. The thought of making pancakes in the library instead of studying was very exciting!! We were split into groups of 4 and our group was tasked to make Western style pancakes. The recipe seemed relatively easy too: crack the eggs, mix in the milk, vanilla extract, melted butter and sugar, mix well and then add the wet ingredients into the dry ingredients consisting of sifted flour, baking powder and salt. After a good mix, the batter is ready.

I thought our group did relatively well in the preparation of the batter even though we had a hard time mixing in the butter because it wasn’t really melted and the measurements, especially for the milk, may not have been very accurate. Regardless, our batter was ready and we went out to start cooking our pancakes!!

This was our group’s first pancake:

Huehue not how you would expect a pancake to look like but I think this was due to 2 main reasons. Firstly, the pan was not hot enough when we added in the batter so instead of having a nice golden-brown crisped exterior, the batter just soaked up the butter and became greasy. Secondly, we flipped the pancake too early. We were supposed to flip after bubbles appear near the center but we were to anxious to flip the pancake so i guess that’s why the pancake crumbled.

Anyway, the first pancake will always somehow end up looking weird so it’s fine!! It was edible and that’s all that matters at the end of the day. 🙂

Our next few pancakes looked quite nice although I think we could have made them slightly thinner!

Tastewise, I felt that the pancakes we made tasted okay, although slightly dry and tough. The pancakes may have been dry due to insufficient milk added since we used plastic cups for measurement instead of a measuring cup, and the volume added would have been different from what was required in the recipe. The toughness of the pancake could be due to over-mixing of the batter as we tried to mix in the unmelted butter for a relatively long time and after we were done, we realised that we forgot to add sugar so we had to mix again. On top of that, we also took turns to mix the batter just for fun so we definitely did over-mix. By over-mixing, we activated the gluten in the flour, leading to denser pancakes, instead of light and fluffy pancakes as promised in the video.

Gluten is a form of protein that is formed when water is added to flour and provides elasticity to dough (especially important in bread making to trap carbon dioxide during yeast fermentation). In the case of our pancakes, too much gluten being developed is actually undesirable.

From this hands-on pancake making session, I learnt more about the dos and don’ts when it comes to making pancakes and I’ll definitely take note of them the next time I make pancakes!

Now, let’s dive into the science behind the making of pancakes. What kind of ingredients go into a pancake and what role(s) do these ingredients play in making pancakes taste like pancakes?

Flour is probably the most important ingredient for most, if not all baked goods. It is what makes up the body of the pancake, giving it its structure and texture. There are many different types of flour available in the market and even though they may all look pretty similar, they actually come with varying protein and gluten content, depending on what kind of wheat they were made from. Hence, it is actually very important to select the right type of flour for the best results. The flour was sifted so as to remove any lumps and also to aerate it, resulting in flour that is smoother and more uniform.

Baking powder is a form of chemical leavening agent that only requires water to activate. After activation, carbon dioxide gas production occurs pretty quickly and the air introduced into the batter allows the pancakes to rise. A leavening agent that works quickly is required as the pancake batter is relatively thin and is incapable of trapping gas within it, unlike bread dough etc. A leavening agent is probably the key to nice fluffy pancakes since the carbon dioxide gas trapped within the batter leads to tiny pockets of air within the pancakes when they are cooked.

Salt is a very much needed flavor enhancer in all kinds of food, even for desserts which may be sweet.  However, it is very very important to just add a small pinch of it, or else we will end up with salty pancakes :”)

Sugar may be optional but definitely necessary for me.

Eggs may also help in holding up the structure of the pancakes while imparting richness and flavor into the pancakes.

Milk is the main liquid ingredient used in this recipe. It helps to dissolve the dry ingredients and hold all of them together, giving the pancakes their structure. Milk also contains proteins which serve as a source of amino acids for the Maillard reaction.

Butter is essentially the fats obtained from milk and fats make things taste good (sorry health nuts) so the addition of butter makes our pancakes richer. Melted butter emulsifies with the eggs and milk, creating better texture. If we were to replace the butter with margarine, the taste of the pancakes would have been different. Butter is a dairy product made from animal fats while margarine is a non-dairy product made from vegetable oil (mainly). Hence, I would assume that pancakes made with margarine will taste less rich and yummy.

Vanilla extract, like salt, is added for enhancement of flavor.

All of these ingredients work hand-in-hand to create the perfect pancake batter! As the pancake batter cooks, one important reaction occurs: the Maillard reaction. The Maillard reaction is a chemical reaction that occurs between an amino acid and a reducing sugar, under heat.

So what does it do and why is it so important? Due to this chemical reaction, a complex mixture of poorly characterized molecules get released and these molecules are what’s responsible for a pancake’s aroma and flavor. This reaction also leads to the browning of the pancakes as they cook. Hence, the Maillard reaction can definitely be considered to be the MVP behind our delicious, golden brown pancakes (and a lot of other foods too).

That is it for this chapter. Thank you for reading!

Hello everyone! Today I’ll be sharing about fermentation.

So what is fermentation? By definition, fermentation is a metabolic process that causes chemical changes of substrates and is carried out by microorganisms such as yeast and bacteria. Fermentation could be used to transform food, imparting complex flavors into food that may originally be plain and dull. It also helps to extend the shelf-life of these foods.

I’ve never really noticed this but fermented food are actually more commonly found in our daily lives than I originally thought! Prior to reading this chapter, when we mention fermented food, kimchi is the only dish that pops up in my mind. Other than that, there aren’t many other dishes which I would correlate the term “fermented” to right off the bat. But thanks to the workshop and readings, if someone were to ever ask me right now to name some fermented food (for whatever reason), I’ll definitely have a longer list of answers to give.

Some fermented food include: kimchi, miso, bread, yogurt, cheese, ketchup, soy sauce, vinegar, beer, wine, kombucha and even nata de coco! Never would I have thought that nata de coco is something that has been fermented. The word “fermented” makes me think of something sour, acidic and pungent – everything that nata de coco is not. How is that even possible?

Workshop

In week 4, we attended a Kombucha fermentation workshop held by Mr Ding Jie. Prior to this workshop, I have actually never heard of Kombucha, much less tasted it before.  If you’ve also been living under a rock like me and have never heard of Kombucha, it is actually fermented tea, and fermentation is carried out on tea (the substrate) by a symbiotic culture of bacteria and yeast (also known as SCOBY). The culture of bacteria consists of lactic acid bacteria (LAB) and acetic acid bacteria (AAB). LAB is responsible for the conversion of sugars into lactic acid, AAB is responsible for the conversion of sugars into acetic acid & cellulose while yeast is responsible for the conversion of sugars into ethanol. After fermentation, the sweet tea actually becomes slightly acidic, alcoholic (about 0.5%) and carbonated. There would be a visible layer sitting atop the liquid and that layer is actually called cellulose pellicle. Nata de coco is actually the cellulose pellicle of coconut water after fermentation!

The taste of the final Kombucha fermented can be affected by many factors, either intrinsic or extrinsic. Some intrinsic factors include the acidity and nutrient content whereas some extrinsic factors include temperature and gaseous exchange. A brief explanation on how each factor may affect the taste of the Kombucha:

Acidity of the culture would affect the fermentation process of Kombucha because the functioning of the yeast is pH dependent. If the pH is too extreme, it may end up deactivating or killing the yeast and fermentation would not occur.

Nutrient content refers to the amount of nutrients present in the culture for the microbes to feed on. Carbon and nitrogen sources such as carbohydrates serve as energy sources, which the microbes require to feed on and grow. If insufficient nutrients are available, the microbes may also be deactivated or killed.

Temperature affects the rate of Kombucha fermentation just like how it affects all other chemical reactions. The rate of fermentation actually follows the Arrhenius equation where every 10 Degrees Celsius increase in temperature leads to doubling of the rate of reaction. There is no rule that dictates how fast or slow the fermentation has to be. The decision on whether to store the tea at high or low temperatures should be based on how we want the final product to taste. Drawing a comparison to the fermentation of wine, winemakers prefer to ferment their wine at lower temperature since lower temperatures extends the duration of fermentation and allows more time for more aromatic molecules to accumulate. Thus, it may be the same for Kombucha.

Gaseous exchange refers to the flow of oxygen in and out of the jar containing the fermented food. For Kombucha, aerobic fermentation occurs first for about a week before it switches to anaerobic fermentation. The tea gets exposed to oxygen for the first week before it gets sealed in a tight jar where oxygen is not allowed to enter.

After making sure that we understand the basis of Kombucha fermentation, Mr DJ handed each of us a jar and a glass bottle, both filled with brown liquid.

The jar on the left contains Kombucha starter culture which is 5 days old. It smells sour, like apple cider. The glass bottle on the right is the final product and is ready for consumption (after addition of sugar).

Using the starter culture, we were given the chance to ferment our own batch of Kombucha! All we have to do is inoculate the starter culture, which is to add some brewed (and cooled) sweet tea to it and then let it ferment for a week under aerobic conditions.

A few important points to note:

• Kombucha is a very “live” drink as it is largely dependent on the microbes present in the mixture. Kombucha prepared by different people would taste different, even different batches prepared by the same person may taste different!
• Brewed tea needs to be cooled first before addition to the starter culture or else the high heat may kill the scoby. Lukewarm tea is also not recommended since lukewarm temperatures cause the mixture to be prone to contamination
• To allow aerobic fermentation to occur, the jar should be covered with a breathable material such as a kitchen towel. This prevents unwanted material/microorganisms to enter the jar while allowing oxygen to flow in and out.
• Sugar added to the fermented tea allows carbonation to occur, causingthe Kombucha to turn fizzy.

However, being the forgetful person that I am , I left my Kombucha totally sealed and unattended to for a few days. When I finally remembered about it, it already looked like this

The cellulose pellicle formed should have been wet, smooth and clear but mine was not smooth and had lots of air bubbles on it. Not sure if it is still safe to drink but fermenting my own Kombucha was definitely an interesting experience for me.

Videos

Here are some interesting facts I’ve learnt while watching the videos about fermentation:

• Fermented food may improve our immune system and reduce risks of some metabolic diseases caused by diets
• Consumption of fermented food introduces the live microbes into our digestive system, interact with our cells and support our microbiota
• Century eggs are fermented not by yeast/bacteria but by chemicals. The eggs are covered in salt, sodium carbonate, tea, ash, quicklime and rice husks. Sodium carbonate and calcium oxide in quicklime reacts to form sodium hydroxide, the main chemical involved in fermentation of century egg. NaOH digests the egg white proteins and the peptides attach themselves to water to form the gel-like texture of the century egg.
• Lead oxide (toxic and fatal if swallowed) is involved in the fermentation of century egg
• Growth of fungi, bacteria and mold on cheese sounds disgusting but these are harmless and are essential to give the cheese complex flavors
• Milk is white but cheese is yellow because the draining away of water from the milk causes the concentration of beta-carotene
• Lactic acid bacteria produces lactic acid which is responsible for fermentation of food such as vegetables
• Addition of salt to cabbages removes water due to osmosis and causes the cabbage to be softer
• Kimchi has fruity notes attributed to geranylacetone & beta ionone and a buttery note attributed to 2,3-butanedione
• Presence of gut microbes could cause changes in brain chemistry and affect psychological stress levels

That is all for this chapter. Thank you for reading!

Hello everyone! I am Audrey, a Year 3 student majoring in Chemistry.

I am sure most of us here love our food, especially all the “good food” we constantly share with others on our Instagram, but what exactly makes these “good food” good?  Why does the same dish taste different when prepared by different people? Is there any science behind the preparation of good tasting food? Through this module, I hope to learn a little bit more about the science behind the food we consume on a day to day basis.

Workshop

In week 1, we attended a coffee workshop held by Mr Swee Heng, the founder of The Coffee Roaster, a cafe which can be found in the Faculty of Arts and Social Sciences in our very own campus.

To start off the workshop, we were handed two different cups of coffee and were told to try both of them. After tasting both, we should try to describe their taste and smell to the best of our abilities, taking note of any noticable differences between the two.

I am not too much of a coffee person actually. I rarely drink coffee because my body is relatively sensitive to caffeine so unsurprising, I am neither great at describing the taste of the coffee nor good at telling different types of coffees apart.

With these two cups of coffee, it took me some time to think about how they smelled and tasted, and what kind of words were suitable to describe them. Smell wise, for the coffee labelled C, it was relatively more bitter as compared to the coffee in the cup labelled E, which smelled more sour. For lack of a better description, I thought the coffee in E actually smelled like kimchi. Taste wise, it was the opposite. Coffee in cup C tasted more sour and acidic while coffee in cup E tasted more bitter.

During the discussion, we learnt that there are only three different species of coffee beans in the world (Robusta, Arabica and Liberica), and we tasted two of out these three. The coffee in cup C was actually brewed from Robusta, a cheaper species of coffee bean since it is more resistant to pests and is more commonly found in our local Singaporean kopis – with a more earthy and slight burnt rubber taste. The coffee in cup E was brewed from Arabica, a slightly more expensive species typically served in cafes – with a more complex flavor of fruit, chocolate and hazelnut. With this piece of information, maybe it can serve as justification as to why a cup of black coffee from Starbucks costs $2.10 whereas Kopi O costs $1.00??

Mr Swee Heng then went on to share many interesting facts about different types of coffee, such as long black, americano, latte, cappucino and macchiato etc.

Here’s a list of some of the things he shared that intrigued me the most:

• Coffee from different parts of the world tastes really different (I’ve always thought coffee was just coffee)
• Espresso needs to be brewed under very high pressure (at least 9 bars)
• Americano and long black are basically the same thing, just that long black has more crema (golden layer above coffee) because for americano, hot water is added after the espresso shot, disrupting its crema but for long black, espresso is extracted directly into the hot water. (I never knew adding the water/espresso shot first could actually make a difference. Who knows maybe the addition of milk/cereal first might also lead to a difference?)
• Flat white, latte and cappucino are basically almost the same thing too, they just have different ratios of espresso to milk to foam.
• Macchiatos does not involve any special ingredients. As long as there is “staining” on the tea (by things like foam/drizzle), it is considered a macchiato.
• Kopi O is bitter because of over-extraction. (More does not equal better)

Many different factors could affect the quality of a cup of coffee. This is where the science behind brewing of coffee kicks in. We learnt that factors such as brew ratio, grind size, brew time and hardness of water are what affects the taste of the coffee as it affects the extraction efficiency.

Brew ratio is the mass of coffee grounds to the mass of liquid espresso in a cup. A 1:1 ratio gives us a ristretto, 1:2 ratio gives us a normale, 1:3 gives us a lungo while ratios from 1:14 to 1:17 gives us a pourover. As the brew ratio increases, the espresso may be less heavy and less viscous. The taste of the espresso would thus differ and may seem clearer.

Grind size of the coffee beans is probably the most important factor that can be controlled through brewing methods. Different preparation methods may call for different grind sizes but generally the coffee beans should not be too coarse but also should not be too fine. If it is too coarse, extraction efficiency may be low but if it is too fine, too much of the coffee bean content may be extracted and that may not necessarily be a good thing.

Brew time affects the taste of the coffee because the extraction of the coffee bean follows the sequence of caffeine, acids, lipids & fats, sugars, carbohydrate and lastly plant fiber. Since carbohydrates and plant fiber are bitter, the optimal stop for the extraction is after sugars have been extracted. An under-extracted coffee would be sour due to the presence of the acids and absence of sugars to balance the sourness out. An over-extracted coffee would be bitter due to the extracted plant fibers and would taste hollow.

Hardness of the water refers to the amount of ions and minerals present in the water. Essential ions required for extraction of coffee include calcium ions and magnesium ions, which means that distilled water containing no ions are not suitable to be used for coffee extraction. Surprisingly, the hardness of the water is a factor that has a great impact on the taste of the coffee. Baristas make their own water (by adding specific ions/minerals to pure water) when taking part in international competitions because hardness of water differs across different countries. Interesting!

It can be seen that there are plenty of factors that could affect the quality and taste of a cup of coffee. All of these ultimately point to one thing – A great deal of science lie behind the creation of a good cup of coffee since the scientific knowledge of the extraction process would allow the barista to fine-tune his/her coffee brewing process to switch up the taste of the coffee he/she creates.

Overall, this coffee workshop was definitely eye-opening to me. Since I do not consume coffee that often, I never knew how complex a cup of coffee may be. The fact that such a common drink could actually have such diverse preparation methods and how much science goes behind the preparation amazes me. Even though we learnt about some technical things in the workshop, it was not boring at all as I could feel how much passion Mr Swee Heng actually has for coffee. In turn it makes me excited to share about the random interesting facts that I learnt from this workshop to my other friends who actually consume coffee on a daily basis.

That is all for this chapter. Thank you for reading!

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