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| Coffeepot (cafetière "campanienne"), part of a service, 1836, hard-paste porcelain, overall: 19.2 x 17.6 x 10.8 cm, Metropolitan Museum of Art |
Exceptionally tasty decaffeinated whole beans & pre-ground coffee are widely commercially available. Ethyl Acetate or Supercritical CO2 or the Swiss Hot Water Process, these methods are widely utilized to selectively solvate away caffeine while leaving the flavors & other compounds naturally present in the coffee.
Roasting decaffeinated beans correctly requires more precision & care, since these decaf beans are lower density. So if your worried about caffeine causing sleep problems, jittery nerves, or other health issues, you can still enjoy the lovely Carmel, Chocolate & Fruit flavors of coffee, espresso or late or cappuccino, without the wakefulness promoting pharmacodynamics of caffeine pharmacology, since caffeine & other compounds in coffee are psychoactive.
Consider Caffeine Wikipedia Pharmacology
Drinking caffeinated beverages causes caffeine to competitively bind to adenosine receptors, boosting cortisol levels which in turn slightly elevate blood glucose by initiating gluconeogenesis in the liver & muscles. By blocking the adenosine receptors, caffeine promotes wakefulness.
Consuming caffeine also releases dopamine in the nucleus accumbens, the parts of the brain that processes pleasure, while caffeine also increases synaptic release of acetylcholine, the neuroplasticity learning & memory enhancing neurotransmitter.
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| Caffeine a competitive antagonist of adenosine receptors in the human brain, its primary mechanism of action accomplished thereby |
In the absence of caffeine and when a person is awake and alert, little adenosine is present in (CNS) neurons. With a continued wakeful state, over time adenosine accumulates in the neuronal synapse, in turn binding to and activating adenosine receptors found on certain CNS neurons; when activated, these receptors produce a cellular response that ultimately increases drowsiness. When caffeine is consumed, it antagonizes adenosine receptors; in other words, caffeine prevents adenosine from activating the receptor by blocking the location on the receptor where adenosine binds to it. As a result, caffeine temporarily prevents or relieves drowsiness, and thus maintains or restores alertness.
Caffeine is an antagonist of adenosine A2A receptors, and knockout mouse studies have specifically implicated antagonism of the A2A receptor as responsible for the wakefulness-promoting effects of caffeine.
Antagonism of adenosine receptors by caffeine also stimulates the medullary vagal, vasomotor, and respiratory centers, which increases respiratory rate, reduces heart rate, and constricts blood vessels. Adenosine receptor antagonism also promotes neurotransmitter release (e.g., monoamines and acetylcholine), which endows caffeine with its stimulant effects; adenosine acts as an inhibitory neurotransmitter that suppresses activity in the central nervous system. Heart palpitations are caused by blockade of the A1 receptor.
Because caffeine is both water- and lipid-soluble, it readily crosses the blood–brain barrier that separates the bloodstream from the interior of the brain. Once in the brain, the principal mode of action is as a nonselective antagonist of adenosine receptors (in other words, an agent that reduces the effects of adenosine). The caffeine molecule is structurally similar to adenosine, and is capable of binding to adenosine receptors on the surface of cells without activating them, thereby acting as a competitive antagonist.
In addition to its activity at adenosine receptors, caffeine is an inositol trisphosphate receptor 1 antagonist and a voltage-independent activator of the ryanodine receptors (RYR1, RYR2, and RYR3). It is also a competitive antagonist of the ionotropic glycine receptor.
While caffeine does not directly bind to any dopamine receptors, it influences the binding activity of dopamine at its receptors in the striatum by binding to adenosine receptors that have formed GPCR heteromers with dopamine receptors, specifically the A1–D1 receptor heterodimer (this is a receptor complex with 1 adenosine A1receptor and 1 dopamine D1 receptor) and the A2A–D2 receptor heterotetramer (this is a receptor complex with 2 adenosine A2A receptors and 2 dopamine D2receptors). The A2A–D2 receptor heterotetramer has been identified as a primary pharmacological target of caffeine, primarily because it mediates some of its psycho-stimulant effects and its pharmacodynamic interactions with dopaminergic psycho-stimulants.
Caffeine also causes the release of dopamine in the dorsal striatum and nucleus accumbens core (a substructure within the ventral striatum), but not the nucleus accumbens shell, by antagonizing A1 receptors in the axon terminal of dopamine neurons and A1–A2A heterodimers (a receptor complex composed of 1 adenosine A1receptor and 1 adenosine A2A receptor) in the axon terminal of glutamate neurons. During chronic caffeine use, caffeine-induced dopamine release within the nucleus accumbens core is markedly reduced due to drug tolerance.
Caffeine, like other xanthines, also acts as a phosphodiesterase inhibitor. As a competitive nonselective phosphodiesterase inhibitor, caffeine raises intracellular cyclic AMP, activates protein kinase A, inhibits TNF-alpha and leukotriene synthesis, and reduces inflammation and innate immunity. Caffeine also affects the cholinergic system where it is a moderate inhibitor of the enzyme acetylcholinesterase.
Caffeine from coffee or other beverages is absorbed by the small intestine within 45 minutes of ingestion and distributed throughout all bodily tissues. Peak blood concentration is reached within 1–2 hours. It is eliminated by first-order kinetics.
Caffeine metabolites in urine +48 hours
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| Caffeine metabolized in liver via demethylation, resulting in 3 primary metabolites, paraxanthine (84%), theobromine (12%), and theophylline (4%), depending on which methyl group is removed. |
Caffeine is metabolized in the liver by the cytochrome P450 oxidase enzyme system, in particular, by the CYP1A2 isozyme, into three dimethylxanthines, each of which has its own effects on the body:
- Paraxanthine (84%): Increases lipolysis, elevating glycerol & free fatty acid levels in blood plasma.
- Theobromine (12%): Dilates blood vessels and increases urine volume. Theobromine is also the principal alkaloid in the cocoa bean (chocolate).
- Theophylline (4%): Relaxes smooth muscles of the bronchi, and is used to treat asthma. The therapeutic doseof theophylline, however, is many times greater than the levels attained from caffeine metabolism.
1,3,7-Trimethyluric acid is a minor caffeine metabolite. 7-Methylxanthine is also a metabolite of caffeine. Each of the above metabolites is further metabolized and then excreted in the urine. Caffeine can accumulate in individuals with severe liver disease, increasing its half-life.
A 2011 review found that increased caffeine intake was associated with a variation in two genes that increase the rate of caffeine catabolism. Subjects who had this mutation on both chromosomes consumed 40 mg more caffeine per day than others. This is presumably due to the need for a higher intake to achieve a comparable desired effect, not that the gene led to a disposition for greater incentive of habituation.
The physiology & biochemistry & metabolism of caffeine much more complicated than this, but these are the major effects that cause caffeine to have psychoactive properties. Much remains to be discovered about the biological effects of the many thousands of other compounds present in coffee, espresso & other aqueous infusion between water & ground coffee beans.
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| Brew Ratios | Coffee to Water 1:1 or 1:25 or 1:40 10 g coffee pulled with 10 g water 1:1 RISTRETTO 10 g coffee pulled w 25 g H2O ESPRESSO 10 g coffee pulled w 40 g H2O LUNGO 10 g coffee pulled with 60 g H2O COFFEE |
A single (official Italian) shot of espresso made with ~7 grams of finely ground coffee contains around ~75 mg of caffeine. Double shot made with 14 g coffee & triple shot made with 21 g coffee. Pull time 25 seconds, at 9 bar pressure & water temp of 90 deg C. Single shot 25 ml, double shot 50 ml, triple 75 ml respectively. Use a gram scale under the shot glass & a timer function scale to time the shot. Scales optimized for espresso analysis start a timer as soon as the mass starts increasing from the expresso entering the shot during the pull.
At 90 centigrade & 9 bars of pressure, the brewing ratio of 1 to 1 for RISTRETTO means that 10 grams of finely ground coffee extract with 10 grams of 90 deg C. water at 9 bars of pressure. Espresso made with 25 grams of hot pressurize water. LUNGO made with a brewing ratio of 3-4+ parts water to 1 part finely ground coffee beans, so you pull a shot with 10 grams espresso grind coffee using 40+ grams of water over 25-35 second pull.
You adjust the pull time by adjusting the grind to the point of diminishing returns. Too coarse of a grind will produce a fast under extracted shot that's acidic and tart in under 20 seconds, that's too fast. Grind your beans finer until it takes about 30-35 seconds to pull a shot. If you grind them too fine, it will take 40+ seconds to pull a shot that's over extracted with bitter flavors that people like me actually like. I actually pull 3 shots out of 7 grams.
The 1st shot 25 ml tastes exceptional, balanced acidity & sweetness with a hint of toasty caramel dark chocolate taste & good mouth feel. The 2nd pull tastes more like the difference between espresso & coffee, perhaps a LUNGO like flavor. The 3rd pull tastes like weak coffee, with a hint more flavor that typical coffee. Again, the resulting brew, regardless of ratio, contains a lot more than just caffeine. The overwhelming majority of the chemical substances in the ground coffee extracted by the hot water are not caffeine.
The world health organization, NIH, many other public & private researchers & scientists & many millions of dollars of research resulted in official intake maximum limit recommendations for most healthy adults of 300-400 mg daily. Other research suggests that the best time to consume coffee, first thing in the morning, black without sugar or cream or milk, while also drinking water upon waking to rehydrate the body since sleeping for 6+ hours causes dehydration. Going for a 10 min walk after drinking your coffee also noted to have broad health benefits, part of staying active & fit, the early morning walk helps to burn the blood glucose released by cortisol from your liver & muscles during the cortisol ramp up before you wake up. During the day, the caffeine metabolized by the liver, its downstream products are excreted as waste.
Roasted coffee beans contain thousands of chemical substances, many substances which are soluble in hot water, the polar solvent H20. You can even cold brew 14 grams of ground coffee in 200 ml of water, in a glass jar, in your fridge for ~12+ hours, it makes a delicious low acidity flavorful stronger coffee that I absolutely love. The floral notes of fruit & dried fruit & flowers comes out along with a delicate salty acidity & a very small amount of roasted chocolate & caramel flavors. A lot of what determines the flavor of cold brew comes down to the how finely ground the coffee is, the brew time & brewing temperature. I have also had better luck improving espresso shots by placing two ice cubes in my shot glass & discharging the espresso directly on the ice. The 90 degree centigrade hot espresso, 7 grams finely ground, extract LUNGO style with 3 pulls of 25 ml each, producing 75 grams of espresso liquid. The ice cools the resulting espresso to drinking temps around 54 centigrade, enjoyable without scalding heat that can damage cells in the mouth, tongue, cheek or throat. When people consume overly hot beverages & thermally denature squamous cells, if done habitually can increase mouth cancer risks.
Espresso rides the line between a science & an art. Measuring out the ground coffee on a gram scale for precise dosing. I aim for 7 grams +- 0.5 grams for a single shot from the OEM pressurized basket of my first espresso machine, a GIVI 430-U in stainless steel. This manual setup allows a lot of shot tuning, a process where you place the shot glass onto a scale & measure how many grams of hot espresso are being deposited into the glass, also timing the shot in seconds, aiming for 25-35 seconds & a head pressure of around 9 bar. Your aiming for a grind level so fine that a espresso grinder with flat burrs & precision step-less adjustment the go to method of grinding beans by enthusiasts. I found the $329 Eureka Mignon Notte hand made in Florence Italy, distributed via Amazon by Seattle Coffee Gear, both local companies near me, as I live ~16 km east of Seattle in Issaquah. I kept the units here, aside from the currency cost in USD2022, in metric SI UNITS of measure since metric measurements are standardized in science & with espresso brewing, which started in Italy around 100 years ago, at the beginning of the 20th century.
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| Palestinian women grinding coffee, 1905 |
Coffee a beverage originating in Ethiopia many hundreds of years ago, as past down in oral tradition, with evidence of around the 15th century. In Yemen, coffee utilized to improve concentration during prayer at Sufi monasteries. Spreading to the Levant & Persia by the 16th century, eventually making it to Italy via Mediterranean trade routes organized by Mamluk & Ottoman global commercialization. By the 17th century, coffee made it to India, the East Indies & Western Europe. Coffee became fashionable in European Coffee Houses, where it would inspire lively discussion of contemporary world topics. High society embraced coffee, where class diffusion later popularized coffee with working class peoples.
It was not all roses and sunshine, coffee controversy often rose up because of how it stimulated lively discussion about all sorts of different topics, some of which were contrary to the interests of the state powers & other social movements during these times in the Middle Ages. In 1674 the "Women's Petition Against Coffee" claimed "the Excessive Use of that Newfangled, Abominable, Heathenish Liquor called COFFEE ...has...Eunucht our Husbands, and Crippled our more kind Gallants, that they are become as Impotent, as Age" Various leaders tried to place restriction on & ban coffee houses, but the delicious intellectually stimulating infusion of ground coffee extracted by water proved all too population for prohibitionary measure to succeed. Over time it became more socially acceptable to drink coffee & in some ways coffee & the caffeine it contains, may have been a driving factor to the intellectual movement in the high renaissance that gave rise to the first industrial revolution & the precursors to all modern applied technology that make the industrial world special to the point where diseases of civilization plague people who are able to sit around without moving much, while the cheapest foods contain excess simple carbohydrates, starches & sugars in addition to the pesticides, artificial preservatives, synthetic dye, pigment, stabilizers, & other questionable ingredients that are hard to pronounce. Read the ingredients of packaged foods that abound in the central isles & shelving of common grocery stores & see what you can plainly read & understand & some of the chemical jargon of the weird & potentially unhealthy or downright toxic components like some of the artificial colors, some of which are sold as chemotherapy drugs, derived from coal tar extracts and analogs created with organic chemical manipulation thereof. Thinks that make the stuff last longer on the shelf, more colorful, more flavors & aromas, but nothing natural or organic, refined oils one of the most common & most questionable in terms of impact on health, think trans fats as they become rancid or oxidize while being heated, trans fats noted for causing very negative health effects.
From wikipedia on the History of Coffee
Composer Johann Sebastian Bach, who was cantor of St. Thomas Church in Leipzig, in 1723–50, conducted a musical ensemble at the local Café Zimmermann. Sometime in 1732–35 he composed the secular "Coffee Cantata" Schweigt stille, plaudert nicht (BWV 211), in which a young woman, Lieschen, pleads with her disapproving father to accept her devotion to drinking coffee, then a newfangled fashion. The libretto includes such lines as:
Coffee tree cultivation spread to Martinique by Gabriel de Clieu, who grew thousands of coffee trees, when exported allowing coffee to be grown in Brazil, Colombia, Ivory Coast, Ethiopia, and Vietnam. Today coffee mass produced. The coffee tree grows fruit pods, coffee beans are the seeds of these pods. The beans are processed from the pods using different methods, dried, then exported. Once in local buying markets, coffee roasters stir fry the coffee beans in a roasting machine, for 2-20 minutes depending on how dark they want the roast. Lightly roasted beans produce a floral fruit sweet coffee while darker roasting brings out toasty, burnt marshmallow, caramel, and chocolate flavors. Coffee's popularity took off after WWII, becoming a household commodity & one of the largest traded commodities worldwide today!
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| Pope Clement VIII: popularized coffee in Europe |
Brewing an aqueous infusion extraction by passion cold, warm, hot or pressured water past ground coffee results in the extraction of soluble fiber. A standardized American coffee contains around 3 grams of soluble fiber. Many western people get around 30% of their daily fiber intake from 3+ cups of coffee. Coffee also packed with polyphenols, healthy oils, complex sugars, essential oils, a whole range of other chemicals & substances other than caffeine. That's why high quality decaf can still taste good if roasted carefully & brewed correctly.
Espresso Flat Burr Grinding
Dialing in an Espresso shot requires trial and error, and doing it correctly requires the scientific method. In particular the successive adjustments of your coffee grinder to get espresso grinds that are fine enough to pull a good shot in 30 seconds without slowing down the extract, indicative of a grind that is too fine.
To dial in an espresso shot you have to measure the mass of the beans, mass of the pulled shot, the flow rate thus calculated. How long did it take in seconds to produce 35 grams of espresso? From there, an optical or digital refractometer can help you determine the TDS or total dissolved solids. Make sure to allow your brew to cool to 25 centigrade before testing the TDS. I also recommend putting your test sample coffee in a sealed container for cooling so that evaporation does not increase the TDS readings by reducing the fluid volume as would happen if a hot fluid sitting in an open container. TDS tells you about your extraction, your aiming for just above 23%. You can also taste test, under extracted tart & acidic, over extracted taste too bitter. A balanced dialed in pull of espresso has a bright vivid acidity & balanced sweetness & mouth feel with a touch of bitter complexity. If you grind is correct, you can pull the shot in 25 to 35 seconds.
A friend of mine, Alicia Long, worked as a barista for several years & said that a pulled espresso shot has to be added to cool or steamed milk within a few seconds to preserve the flavors of the result Latte or Cappuccino! I noticed that placing ice in the shot glass to rapid chill the espresso also greatly improved the flavors of under extracted espresso, since my high speed blade spice grinder cannot produce super fine grounds, like the Eureka Mignon Notte I am waiting for :)
When you order stuff online there is a delay for processing the order & shipping, usually between 2 hours & 5 days, from my experience. Yes, some Amazon orders ship same day locally, probably in part because I live near Amazon, many Amazon distribution centers & the corporate HQ. Seattle Coffee Gear the group that sold me the Notte also a local company. GIVI the Italian company that designed the 430-U, produces them at a Chinese manufacturing plant. This results in entry level price of around $100. Italian made espresso machines typically cost many hundreds or thousands of dollars. All said, I am into the Espresso setup around $600 so far.
I abstained from buying an espresso tamper & 3D printed one in white PLA from a Thingiverse file for a 51mm brewing basket designed by someone else. This file was downloaded, imported into Slicer. I tweaked the base layer to 3mm & increase shell count to 8. Using 80% Grid Infill, it took about 5 hours to print on the PRUSA MINI. I wiped down the PEI coasted steel bed with an isopropyl alcohol wipe to remove finger oils & dust.
I had not used this 3D printer for months, its in my bedroom on a shelf assembly next to by bed, and it fired right up. On my iMac, I plugged in a USB drive, using the Slicer software to slice the 3D model with the strength optimized print settings, as a g-code file, then exported the filed to the USB key, then ejected & removed the USB dongle. Installing the drive into the PRUSA Mini, I plugged in the power supply to the NEMA 15R 120v 15 amp power out. I cleaned the printing bed, turned on the unit, selected the correct g-code, and started the print. Auto-bed leveling & nozzle purging were nominal & the 51mm PLA espresso tamper printed flawlessly on the first try, thankfully. The 3D printed PLA tamper has a mass of around 80 grams.
It feels nice in the hand & has more than 150 KG of compressive strength according to the material specs, 3mm base & shell & 80% grid infill, according to evidence from CNC kitchen testing & other online resources about 3D printed parts strength, infill strength analysis & other evidence I gleaned while researching the best print settings for the part. I always increase orbital shells on parts that need strength, aiming for a few millimeters or more. If you think about the FDM deposition, line by line, layer by layer, more shells creates force distribution improvement, just as many weak strands in a rope combined produce a very strong rope.
Line by line & layer by layer, the melted plastic fused together to make a part with a ridge on each layer, akin to tree rings, the layer height was set to 0.20mm Quality. I found that 0.2mm Quality with the OEM 0.4mm nozzle produces the strongest parts. 0.15 & 0.10 produce more part detail, and slowing down the print by 50% or more seems to improve printing precision. FDM already a very slow process. Small prints take many hours, many hundreds or thousands of layers with many more lines on each layer. The g-code a kind of machine language that tells the microcontroller how much & when to spin the axis drive & extruder/ retraction motors.
As the PLA filament enters the 3D printer, a gear driver mechanism pressure grab the plastic so that it can pull or shove the filament into the hot end, where the plastic exists to be deposited on the part. Its like controlling the bubbles in an injet printer nozzle, the extruded plastic will form thin fine hair like strings or stringing if the part has complex geometry & the hot end temp too high or the retraction or flow rate are off. There are How to Reducing Stringing in 3D FDM Printing YouTube videos & many other educational DIY 3D printing video tips & tricks on YouTube. I really like the CNC Kitchen channel.
You might wonder how caffeine & 3D printed are related. Well, in part, caffeine stimulates wakefulness. You do not have to be awake to 3D FDM print, though I high recommend supervising the start of the print, as most printing errors occur during the first few layers, which typically only take a few minutes to print. If you have good bed adhesion by cleaning the bed with isopropyl alcohol, using a PEI steel sheet as the bed, heating the bed to 60 centigrade, these are the best ways to insure a good first layer bond. The most important aspect of getting a high quality FDM print & first layer bond, is your Z calibration of adjusting how far the nozzle is from the print bed. You are going for enough squish of the emitted filament that it promotes good binding to other lines later deposited, you want the lines to melt together, the hot end can fuse the lines as it precision lays them next to each other. Too much squish is bad, it produces a ribbon that causes delaminating error failures right away. Not enough squish, the lines do not bond & your part is going to be very weak, able to break easily. Dial in that first layer height carefully. This is the most important part of setting up your 3D printer for successfully printing parts.
I am sure that many younger people who 3D print as a hobby consumed energy drinks, many of which have a high caffeine content, like 300 to 400 mg. Thankfully, most energy drinks also contain vitamins which are essential chemical substances for the biochemistry of the body. I do not think that energy drinks are healthy to consume, especially because many consumers of energy drinks drink more than one & many energy drinks contain a lot of sugar, which is a metabolic poison to people who live a low activity level or sedentary lifestyle, think typically sitting too much American lifestyles that give rise to high blood pressure & type 2 diabetes & heart diseases & dementia & Alzheimers. I think the major common cause from sugars, starches, carbohydrates, especially high glycemic index carbs that raise blood sugar levels. Say Insulin, Insulin, Insulin, the regulatory hormone that tells body cells to uptake or take in blood sugar. When people eat too much sugar or foods that produce blood sugar rapidly, this overwhelms the insulin signaling cascade & promote disease formation. This is why I like my espresso & coffee black, drink my tea neat without sugar or milk. This is why I like water as my favorite beverage & try to stay active & keep my sugar intake to a low level.
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