Espresso

Gevi 15 Bar Professional Espresso Maker & 1.5L Removable Water Tank, in Silver, 1100W

Making espresso with a pressurized near boiling water system was invented in Italy at the end of the 1800's, machines made in small volumes were produced 1 per day by an Italian craftsman. Early espresso was designed to make fast coffee, very different from espresso pioneered after the 1940's, which is a concentrated coffee extract that people call a shot, that baristas "pull a shot" since the first of such machines were entirely manual & contains a lever that was used to pressure extract the coffee with near boiling water. Coffee contains the worlds most popular psychoactive stimulant, caffeine, but also contains lots of other biochemicals & compounds that contribute to its nutritional profile, mouth feels, flavor, aroma, smell, all of which are strongly influenced by where the coffee trees are grown, the climate & weather of that year, the soil conditions, the roast of the beans, the level of grind fineness, the brewing water temperatures & how long the water in contact with the ground coffee, how fresh the coffee is, and other variables. 

Coffee is not caffeine, any more than a banana is sugar, or cheese is milk. The roasting of coffee produces many other flavor compounds, such that darker roasts tend to have more flavors, deeper more bitter notes, less floral & more "burned", just as barbecuing or smoking foods can add more flavor, or the way they roast the inside of oak barrels for spirit making, softening the neutral spirits & adding wood chemicals that produce whisky, bourbon & other spirits. Charing while cooking produces similar reactions that produce more flavor chemicals & more aroma & a bigger  taste profile. 

Espresso a 15-20 bar high pressure (278-290 psi) near boiling hot water 197 F (91.7 C) extraction of ground coffee beans that produces a symphony of flavors in with notes of bitter caffein mix with thousands of other compounds extracted from the roasted coffee bean grounds. This specific temperature pressure generated by a water boiler & motor driven mechanical pump that directs the heated pressured water through the filter assembly filled with coffee ground & produces an optimal extraction known as "Crema" 

The filter handle made of a metal cup with a rubber gasket & plastic assembly inside, with a plastic handle, into which a portafilter with a plastic filter valve assembly inside inserted, which contains 8-16 grams of coffee grounds, that a tamping tool used to compress to about 30 lbs (13.6 kg) of compression pressure to make a compact cake of coffee grounds. Unhappy with this plastic inside of metal design of the basket & portafilter, I ordered an aftermarket 51 mm stainless steel basket holder & basket with a wood handle, bottomless for $40 

This kind of bottomless filter eliminates the pouring spouts & other stuff in the way & allows the extracted espresso to exit in a beautiful display like this, directly into your espresso cups, in my case hand blown double-wall clear glass containers, the 4 pack listed later in this posting. 

The stainless $13 stainless steel tamper I ordered on amazon arrived in its foam envelope missing. The box containing it was smashed & the end of the envelope was torn open. Amazon gave me my money back after I gave them my phone number & customer support called me.  I used the refund applied to my prime account about 2 hours later to get a dosing filter for the same price. It is made of machined aluminum & contains 4 magnets to hold onto the filter basket easily, which makes adding the on demand super fine ground espresso bean powder easier to add to the basket without spilling. 

I was using a cheap high speed blade spice grinder to grind my coffee beans, but it always produces a spectrum of particle sizes, super fine dust mixed with big chunks like rock salt. Its also super loud & heats the coffee to over 100 F (warm hot) after just 20 seconds of pulse grinding to get to near espresso size. Doing many hours of research on YouTube I found a coffee expert James Hoffman (Expresso Explained <- click link) by mining his YouTube videos I learned about conical & flat burr grinders that grind the coffee more evenly & at lower speeds & lower temperatures. 

Espresso enthusiasts use high quality expensive NICHE Zero or Option-O Lagom P64. On Amazon you can find several different Espresso machines that make super fine grinds, ranging from the $199 for the Breville Smart Grinder Pro to the $299 Fellow Ode, or the $425.00 Rancilio Rocky Espresso Grinder, or the MiiCoffee DF64 Single Dose Coffee Grinder. 

I went with the $329 Eureka Mignon Notte Espresso Grinder. The build quality, stepless micrometric regulation, hardened steel flat burr set, high quality 260w powerful 1350 RPM motor combine in an exception machine Made in Italy & built by hand in Florence. The innovative bottom burr adjustment lets you disassemble it for cleaning & reassemble without losing your dialed in grind setting, a feature unique to Eureka grinders & important for Espresso enthusiasts. It was the best cost, build quality, performance, value combination, slotting in the middle of the price range for a quality espresso grinder.  Special thanks to Seattle Coffee Gear & their education YouTube videos & for being the seller on Amazon. With espresso, your grind quality affects the final flavor by changing the resistance of the flow in the basket as the coffee puck made with finer grinds exposes more surface area, good up to a point for complete extraction, but coffee can be ground too fine & form a jam that results in over extracted excessive bitterness. 

Eureka Mignon Notte Espresso Grinder

Dialing in the exact grind size for your specific setup & kit a process. I suggest watching YouTube videos about how to dial in your espresso grind to learn more! A quality grinder fresh grinding beans on demand, can produce higher quality espresso in a cheaper espresso machine. Also, the bottomless kit I ordered divergent from the pressurized basket that shipped on the GIVI as default to give novice users the ability to use less finely ground coffee to produce OK espresso shots, many because many of the users of such machines, like the GEVI 403U that I got, use pre-ground coffee (yuk) in bags. I did that for a while with the reusable steel K-pod in our disused KEURIG MINI. I also brew coffee in a newer red numbering on smoked polypropylene (Newer Model) Aeropress Made in America. James Hoffmann videos about how to get the best coffee out of an Aeropress are absolutely excellent if you want better tasting coffee from your Aeropress. 

Automatic Time Scale For Shot Pull Analytics 

The Espresso Mode & Pour Over Modes + Manual Mode Improves Value 

When your pulling an espresso shot & tuning in your grind size, your aiming for a certain extraction ratio like 10 grams of coffee to 25 grams of espresso out, in 25-30 seconds, indicating a proper pull, evidence ultimately should be a shot with balance salt, sugar, acid & bitter components, for a well rounded flavor that is not overly tart or overly bitter. Using a scale with an automatic time can help to dial in that shot, by adjusting your grind size from medium fine to very fine, up to the point where flow rate slows such that pull the same shot takes longer, then you dial back to a hint less fine or a tad more coarse. Your smell & taste preference will ultimately tell you what you like, but if you want to dial in official espresso shots, that's how you do it! 

On Amazon.com I got this BOMATA Coffee Scale with Auto-Time 0.1g/3kg, Drip Detection, Automatic Timing & Locking with Type-C USB charging of its internal 1200mah lithium polymer battery, it can also run on 3x AAA alkaline or lithium iron disulfide primary cells. For ~$24 shipped with tax, it was the best deal. The Hario V60 Scale was much nicer, but 50% more expensive. 

GEVI GECMC403-U 

The unit heats up quickly, something like 25 seconds like the manufacturer claims in its specifications for this machine. I ran some cleaning passes & washed the basket & holder & glass cups with dish soap & hot water. You brew hot water through the setup, collect & discard the cleaning water, up to 3 times. After you brew & stop, you press the milk frothing button, then purge the milk steamer setup a few times to clean that system out too. After 3 hot water passes, its ready to use. I used my cheap electric coffee grinder to grind 13.2 grams of 10% Kona blend medium roast beans into a very fine 600 micrometer espresso super fine grind & loaded it into the basket with the included plastic scoop tamper combo tool. I was able to brew up two glasses of espresso, 2 oz or around 60 ml each, with good strength, taste & color. I steamed about 4 oz of organic whole milk in a cup, then added the double shot of espresso to the cup to make a cappuccino & it was good. 

Sequential Rapid Shots Pulled with Soft Touch of Steam Button

Through ongoing use & testing I find that hold the steam button without clicking it, heats up the water, which cools below the optimum brewing point fast while pulling a shot, so if you want to rapid fire two pulls, this is the trick, keep an eye on the thermometer, it has some thermal inertia, so let off before it hits the espresso cup icon & the water keeps heating a little more. 

Dual temp control for brewing & milk frothing

Frothing the milk with the steam want through the stainless steel pin-socket enables smoother milk frothing while the machine produces steam at the boiling pot of water 100 C or 212 F, using a separate heating control thermostat to create the correct temperatures for both steps. The steamer spatters out hot water at first, so purge that into a separate container before steaming your milk FYI. 

You might wonder why people mix espresso extracts with frothed milk. Thats because the milk contains fats and proteins & lactose that produce fine bubbles with the steam want inserted a few mm or 1/4 inch into the surface of the milk held in a heat resistant container. As the hot steam pressure blown into the milk, the milk forms a bubbly froth. This increases the surface area of the milk such that its mixing with the expresso provides more interaction space so that the milk components can soften the bitter flavor notes while adding smoother mouth feel and sweet flavor from the lactose & other milk sugars, fats & proteins. 

Known as milk frothing, this typically done in a 250 ml stainless steel measuring cup, but can be done inside a ceramic mug or other heat resistant container. This unit includes an adjustment knob to control the milk foaming steam output. You can see the potential to make LATTE or CAPPUCCINO art by carefully pouring steamed milk foam into the espresso. Pin holes in the stainless steel foamer inject tight compact streams of steam into the milk, increasing the fine delicate milk foam production rate by creating more tiny bubbles faster. 

Small double wall glass cups utilized to capture the espresso output of the machine. This dark black liquid espresso can be enjoyed on its own, I personally love to sip it black with nothing added, though most baristas & coffee lovers prefer to mix the espresso with steam foamed milk for a smoother sweeter flavor profile. 

Sweese 408.101 Espresso Cups - 4 Ounce Double-Wall Insulated Handmade Glasses

Since the espresso exists the machine at temperatures hot enough to scald your fingers, using double wall glass cups provides a thermal insulation where the outside of the cup stays cool to the touch even though the inside of the cup holds scalding hot espresso. This facilitates easier safety handling of the espresso to transfer it into a mug to make a beautiful cappuccino. You can also just add cold water to the mug with the espresso, that helps drag down the temperatures to a mouth safe range so you do not scald your lips or tongue. Adding cool water to the hot espresso also helps to make more flavors bloom, by cold crashing some of the components out of the hot infusion, which float to the surface as micro droplets that interact with the taste receptors on the tongue to produce a more flavor packed drinking experience. 

On Amazon dot com,  the above espresso machine, tamper & cup set totally $165 Happy 39th Birthday to me today Sept. 4th 2022 :) Yes, I purchased this kit yesterday night, after doing more than 3 years of online research into espresso machine & final 2 hour round of reviews last night. I wanted something affordable with a good quality stainless steel boiler, stainless steel pump, at least 15 bars of pressure, and don't care much about milk foaming personally. I usually brew my coffee & drink it black with nothing other than cold water added to cool the hot coffee to mouth safe ~ 130 F (59 C) temps. 

I started drinking coffee the day that my late brother in law & then best friend Drake died of complications from leukemia treatment. My sister had purchased my mother a Keurig Mini machine & so the journey into coffee pods started. After many single use pods, I got 2 reusable stainless steel pods & started buying ground coffee in bags. After a while of using this setup, I got an Aeropress manual coffee brewer. I have been using that one nearly daily for over a year. I had started researching coffee with my late friend Matt Mayo back in 2003. He envisioned opening a coffee shop. Most of the commercial machines costs thousands of dollars & do not make sense for home use. More recently because of constantly online reading, perhaps in 2017, I started doing research of caffeine, coffee & tea. Meg & at the time were avid tea consumers. My favorite tea green tea, brewed with 174 F water, for 4 min 20 seconds. I had been drinking green tea since around 2003. 

1100 watts of electricity enter the espresso machine, where the control switching logic via an on off button, brewing button & foaming button, activate heating sequences where the electrical boiler heats water from the removable water tank, to near boiling temperatures, while an electric motor driven pressure pump takes the heated hot water from the boiler & pushes it through the brewing handle in which ground coffee tamper compressed into a cake inside the filter assembly in the handle so that the hot water can fully extract the coffee grounds to make espresso, which is typically collected in small double walled glass cups. This espresso then poured into a ceramic mug into which finely foam milk carefully added to make a Latte or Cappuccino drink that billions of people enjoy daily. Coffee one of the worlds most popular beverages because it contains the only OTC legal worldwide nootropic compound, caffeine, an competitive adenosine receptor agonist that blocks adenosine from activating the adenosine receptor, to promote wakefulness thereby. Normally, adenosine levels elevate throughout the day and along with melatonin, created feelings of tiredness or sleepiness to promote sleeping as part of the circadian regulatory mechanisms or circadian rhythm that regulates sleep & waking processes in the human brain & body. This is very simple overview of the way that caffeine works. 

Amateur Tuning of Espresso Machine

Use high quality water, it affects the final flavor & extraction efficiency

Use high quality coffee & grind it on demand right before making an espresso shot

A single shot dose 7-9 grams, a double shot dose 14-18 grams, sometimes more

Aim for 25-35 seconds extraction time

Your trying to pull about 20-30 ml for a single dose or 40-60 ml for a double dose

Clean your basket before & after you use it

Use a high quality slow speed conical grinder & grind to finer sizes for making espresso

If you grind too fine, your machine will struggle & not pull a shot fast enough, it can clog the basket. I would put that into a filter coffee maker for further extraction so as to not waste your coffee. 

You can pull more hot water through your coffee puck into another container for weak coffee after pulling your primary shot from the puck. I call this Eisenhower coffee, extracting the puck 3 x or more to get everything, even if it tastes acidic or bitter. Each pull gets lighter in color & has less or different flavors. Meg actually likes the 2nd pull better than the primary, as its less powerful or less strongly flavored. I never add sugar or creamer to my espresso & enjoy it neat or without additives. I have fooled around with steamed whole milk or a dash of that added to the shot. I have also combined pull 1 & 2 & 3 into a cup with a little dash of whole milk added to smooth it out. I am still brand new & learning about espresso making as a beginner & just sharing what I am learning as I go. 

Dialing in your grind & using a quality grinder more important than your machine

Study your machine while you use it, noting the temperature control, what is the actual temperature of the espresso in your cup after it exist the machine. Conical burr grinders that spin slower as your best bet, as they heat up the coffee less & produce a more consistent grind particle size output, with more uniform grain dimensions, which makes a more precise espresso pull. Only change one variable as you are learning by experimenting, that way you will be able to tell exactly what changed and why. Never change two variables, otherwise its impossible to know which affected the output more. In science, you always isolate the variable of interest. If you want to change your dose in grams, keep the grind size the same, brewing temp the same, brewing time the same, brewing ratio the same, same kind of water, etc. More likely, to dial in your espresso, keeping all else the same between pulls, slowing dial in a finer grind, such that each successive grind produces small grains of ground coffee. You will reach a jam point, where its too fine & the water creates a mud lock. You are not brewing with coffee dust to make espresso, your aiming for fine grind grains in the 400 to 600 micrometer range, a little smaller than common table salt crystals. 

Examine the spent espresso grounds when you remove the basket to pitch them, you can add them to your garden or compost bin to make soil with the spent coffee grounds. They also make a nice dried additive in soap making to act as a exfoliating scrub component, as does vitamin c crystals, sand or volcanic rock pumice. 

From the Wikipedia article on Caffeine 

Caffeine is a central nervous system (CNS) stimulant of the methylxanthine class used as a cognitive enhancer, increasing alertness and attentional performance. Caffeine acts by blocking binding of adenosine to the adenosine A₁ receptor, which enhances release of the neurotransmitter acetylcholine. Caffeine also increases cyclic AMP levels through nonselective inhibition of phosphodiesterase. 

Caffeine is a bitter, white crystalline purine, a methylxanthine alkaloid, and is chemically related to the adenine and guanine bases of deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). It is found in the seeds, fruits, nuts, or leaves of a number of plants native to Africa, East Asia and South America, and helps to protect them against herbivores and from competition by preventing the germination of nearby seeds, as well as encouraging consumption by select animals such as honey bees. 

The best-known source of caffeine is the coffee bean, the seed of the Coffea plant. People may drink beverages containing caffeine to relieve or prevent drowsiness and to improve cognitive performance. To make these drinks, caffeine is extracted by steeping the plant product in water, a process called infusion. Caffeine-containing drinks, such as coffee, tea, and cola, are consumed globally in high volumes. 

In 2020, almost 10 million tonnes of coffee beans were consumed globally. Caffeine is the world's most widely consumed psychoactive drug. Unlike most other psychoactive substances, caffeine remains largely unregulated and legal in nearly all parts of the world. Caffeine is also an outlier as its use is seen as socially acceptable in most cultures and even encouraged in others, particularly in the Western world

Tolerance to the autonomic effects of increased blood pressure and heart rate, and increased urine output, develops with chronic use (i.e., these symptoms become less pronounced or do not occur following consistent use)

Caffeine is classified by the US Food and Drug Administration as generally recognized as safe. Toxic doses, over 10 grams per day for an adult, are much higher than the typical dose of under 500 milligrams per day. The European Food Safety Authority reported that up to 400 mg of caffeine per day (around 5.7 mg/kg of body mass per day) does not raise safety concerns for non-pregnant adults, while intakes up to 200 mg per day for pregnant and lactating women do not raise safety concerns for the fetus or the breast-fed infants.

A cup of coffee contains 80–175 mg of caffeine, depending on what "bean" (seed) is used, how it is roasted (darker roasts have less caffeine), and how it is prepared (e.g., drip, percolation, or espresso). Thus it requires roughly 50–100 ordinary cups of coffee to reach the toxic dose. However, pure powdered caffeine, which is available as a dietary supplement, can be lethal in tablespoon-sized amounts.

Espresso from Wikipedia 

Espresso (/ɛˈsprɛsoʊ/ (listen), Italian: [eˈsprɛsso]) is a coffee-brewing method of Italian origin, in which a small amount (2 oz or ~50ml) of nearly boiling water (about 90 °C or 190 °F) is forced under 9–20 bars (900–2,000 kPa; 130–290 psi) of pressure through finely-ground coffee beans. Espresso can be made with a wide variety of coffee beans and roast degrees. 

Espresso is the most common way of making coffee in southern Europe, especially in Italy, France, Spain, and Portugal. It is also popular in Switzerland, Croatia, Bosnia and Herzegovina, Bulgaria, Greece, and Australia.

Espresso is generally thicker than coffee brewed by other methods, with a viscosity similar to that of warm honey. This is due to the higher concentration of suspended and dissolved solids, and the crema on top (a foam with a creamy consistency).

As a result of the pressurized brewing process, the flavors and chemicals in a typical cup of espresso are very concentrated. Espresso has more caffeine per unit volume than most coffee beverages, but because its usual serving size is much smaller than (for example) drip-brewed coffee, the caffeine content of a single serving of espresso is generally lower than that of a mug of drip coffee.

The actual caffeine content of any coffee drink varies by size, bean origin, roast method and other factors, but a typical 28 grams (1 ounce) serving of espresso usually contains 64.5 milligrams of caffeine, whereas a typical serving of drip coffee usually contains 150 to 200 mg.

The three dispersed phases in espresso are what make this beverage unique. The first dispersed phase is an emulsion of oil droplets. The second phase is suspended solids, while the third is the layer of gas bubbles or foam. The dispersion of very small oil droplets is perceived in the mouth as creamy. This characteristic of espresso contributes to what is known as the body of the beverage. These oil droplets preserve some of the aromatic compounds that are lost to the air in other coffee forms, enhancing the strong flavor of espresso.

Espresso is served on its own, and is also used as the base for various other coffee drinks, including caffè latte, cappuccino, caffè macchiato, caffè mocha, flat white, and caffè Americano.

The act of producing a shot of espresso is often called "pulling" a shot, originating from lever espresso machines, with which a barista pulls down a handle attached to a spring-loaded piston, which forces hot water through the coffee at high pressure. However, it is more common for an electric pump to generate the pressure.

Tamping down the coffee promotes the water's even penetration through the grounds. This process produces a thicker beverage by extracting both solid and dissolved components.

The "crema" is a layer of dense foam that forms on top of the drink.It consists of emulsified oils in the ground coffee turned into a colloid, which does not occur in other brewing methods. Crema is produced when water, placed under very high pressure, dissolves more carbon dioxide, a gas present inside the coffee that is produced during the roasting process.

Technical parameters by Italian Espresso National Institute for making a "certified Italian espresso" 

Parameter	Value
Portion of ground coffee	7 ± 0.5 g (0.25 ± 0.02 oz)
Exit temperature of water from unit	88 ± 2 °C (190 ± 4 °F)
Temperature in cup	67 ± 3 °C (153 ± 5 °F)
Entry water pressure	9 ± 1 bar (900 ± 100 kPa; 131 ± 15 psi)
Percolation time	25 ± 5 seconds
Volume in cup (including crema)	25 ± 2.5 ml (0.88 ± 0.09 imp fl oz; 0.85 ± 0.08 US fl oz)