Questions tagged [chemistry]

All about the chemistry of coffee, from the Maillard reaction to the extraction of dissolved solubles in coffee.

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Question about coffee brew chemistry

Does anybody know, what happens, when you brew coffee for a long time and/or on a high temperature (above 100°C). I found only this: Temperature affects the solubility and volatility of the coffee ...
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Is black coffee a solution, a colloid or a suspension?

I've only gotten answers about normal coffee, like with milk in it. There is nothing about black coffee so could you help me? Is it a solution, colloid, or suspension?
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What is the process of coffee acting as a taste blocker in conjunction with menthol/mint

Background, I vape a mint (spearmint and peppermint) with menthol. When I drink any kind of coffee and for some time after, the vape has a different (not so nice) taste. It can be black coffee, ...
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2 votes
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Does L-theanine affect caffeine's half-life?

Does consuming L-theanine with caffeine, either in drink (like matcha) or in pill form, affect the half-life of caffeine? I have heard something like "L-theanine slows caffeine absorption", ...
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1 answer
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Why is coffee sometimes nitrated but never carbonated?

I've seen a lot of cold "draft" coffee appearing that is infused or pressurized with nitrogen gas (as with Guinness beer). The added nitrogen leads to a "smooth, creamy" mouthfeel....
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How to make a "normal" cup of coffee with instant coffee

I drink freeze dried instant coffee usually and when I have it I find that it is much stronger than regular brewed coffee. I figure that im putting too much powder in. This got me thinking, if one ...
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What is the industrial method for extracting caffeine to make decaf? [duplicate]

Is this a solvent extraction method? If so what solvent is used and if it is organic, do the manufacturers verify elimination of a certain percentage of residual solvent?
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2 answers
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What type of coffee maker creates the most coffee scent?

I stopped drinking coffee for a while but recently picked it back up, mainly because I enjoy the scent. Previously I had a Keurig machine; convenient, but produces almost no smell during brewing. ...
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Effects of coffee consumption on testosterone production

Does consumption of coffee affects hormone, precisely testosterone production in a noticeable way? And if so does it increases it or decreases it? Also I'm not looking for any type of super ...
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3 votes
3 answers
242 views

What acids are there in coffee?

I don't know what acids extract with what temperature. For example, in 93 °C what acids hurt and what acids extract. I want to know for better flavor and less bitterness in my espresso, what can I do?
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5 votes
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How much "coffee" is there in my cup?

Kind of a strange question... Suppose you brew your coffee to your liking, a v60 filter or an espresso. The ingredients are water and coffee grounds. But how much 'coffee' is there actually in the ...
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Using Arabica coffee beans for making instant coffee

I saw in this article that instant coffee is usually entirely consisting of Robusta beans. Would making a instant coffee of Arabica beans make a better quality instant coffee? Would the process making ...
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Could light transmittance be used to timely determine extraction?

I was wondering if I could get perfect extraction timing by measuring the light transmittance (of course with the same coarseness of grind) like a Beer's law sort of thing. Anyone have any readings? ...
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10 votes
7 answers
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Warm Brew Coffee?

I usually hot brew coffee as it's the most convenient method. I occasionally cold brew coffee for a less bitter coffee, which I prefer, but is a bit of a pain in the a***. I'm assuming the bitterness ...
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7 votes
0 answers
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Empirical data on reuse of grounds, by flow and filter

We wanted to know are there quality empirically generated chemical composition tables examining the relationship between filter porosity, flow by volume per time, and grounds of different varieties?
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12 votes
2 answers
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Theobromine in coffee

Wikipedia lists coffea arabica as a plant species with a high theobromine content, but does not include coffee on the list of significant dietary sources. I searched around, and it looks like the ...
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Why do aeropress columns get abrasions, or scars, near the top?

A friend and I both have aeropresses that have been through 2-4 years of use. I noticed that mine has what looks like coffee-stained abrasions near the top of the column, furthest away from the filter....
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2 answers
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Can I reduce harmful terpenes?

There are reports that terpenes in coffee made without a paper filter raise cholesterol and risk of atherosclerosis / heart disease. (See Coffee and Cholesterol and Warning: Going to the Coffee Shop ...
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Is it good to have the "floating oil" on the surface of some coffee drinks?

Coffees prepared with some standard home machines (e.g., non-paper-filtered methods like moka, Turkish, or even some espresso machines) have something on the surface. It looks like oil from the beans. ...
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Why do some grounds float and others sink when brewing by pour over

When brewing by the pour over method (in my case with a Chemex) I've noticed that some ground beans will float when I fill the filter with hot water, and other beans will not float. It's consistent ...
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10 votes
1 answer
328 views

Is stale coffee less healthy for you than fresh coffee?

I recently read an article on chemistry of grinding coffee beans and it suggests stale coffee might be less healthy than freshly-roasted coffee, in terms of micronutrient and antioxidant loss over ...
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6 votes
1 answer
170 views

Does coffee really stunt your growth?

I have heard that coffee (or other chemicals such as caffeine in it) can actually prevent you from growing. Is this really true?
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4 votes
2 answers
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Quantifying flavor differences between varieties?

Different coffee varieties can produce very different flavour profiles. A different flavour profile points to differences in the chemical mix inside the cup. Are there any studies that quantify ...
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Is decaffeinated coffee more acidic?

Apparently caffeine is weakly basic. This means, presumably, that in coffee the caffeine actually neutralises some of the acids. Is decaffeinated coffee more acidic than caffeinated coffee as a ...
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12 votes
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Is coffee a solution or an emulsion?

According this article about the chemical composition of coffee, 12% of the dry weight of green unroasted coffee beens are chlorogenic acids. It does not mention if these acids fully dissolve in water ...
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