In an op-ed published at Law&Crime this Tuesday, former chief White House ethics lawyer Richard Painter and Yale psychiatrist Bandy X. Lee argue that President Trump is not fit to stand trial for impeachable offenses "because of his apparent mental incapacities."
Despite the pair's credentials, they point out in the op-ed that "one need not be a Board Certified Psychiatrist or a former White House Ethics Counsel to see that Donald J. Trump is not psychologically well."
"Currently the one person designated by the U.S. Constitution as Commander-in-Chief and thus authorized to order the use of nuclear weapons—at his whim—has, in all likelihood, a severe and serious mental impairment," the pair writes.
If a Senate trial were to move forward, Trump must first be declared "mentally competent to stand trial under the principles of Justice well established in the United States."
"Until there is an evaluation, the determination that he is competent to stand trial cannot be made, nor assumed," the op-ed states.
"To be debating whether you should have the evidence admitted, to be debating whether you should allow witnesses, is to be debating whether you should have a cover-up," Chairman Nadler accused.
— (@)
McConnell late Monday released the rules under which the Senate will try the President, starting this week, for the high crimes and misdemeanors of abuse of power and contempt of Congress. Those rules force votes on nearly every aspect, including whether or not to take up the issue of whether or not to allow witnesses.
The rules also force a vote on each and every document that would be submitted into evidence. By contrast, the Senate impeachment trial of President Bill Clinton automatically allowed the evidence the House had included in its impeachment to be submitted to the Senate.
President Donald Trump's historic impeachment trial begins in earnest Tuesday in the Senate, with Democrats calling for his removal from office and Republicans determined to acquit him -- and quickly, if possible.
Four months after the Ukraine scandal exploded and went on to overshadow the end of Trump's term, and 10 months before Americans go to the polls to decide whether to re-elect him, the 100 members of the Senate will gather at 1 PM (1800 GMT) with chief justice John Roberts presiding over the trial.
The job of these lawmakers, sworn in last week as jurors, is to decide if Trump abused his office and obstructed Congress as charged in two articles of impeachment approved last month by the House of Representatives.
They state that Trump tried to pressure Ukraine into interfering in the 2020 US election to help him win, and then tried to thwart a congressional probe of his behavior.
It will be only the third time a president has endured an impeachment trial, after Andrew Johnson in 1868 and Bill Clinton in 1999.
Part of the scandal centers on a July 25 telephone call in which Trump pressured Ukrainian President Volodymyr Zelensky to announce an investigation of former Vice President Joe Biden, Trump's potential opponent in the November vote.
Democrats, who control the House of Representatives and led the investigation, accuse Trump of manipulating Ukraine by withholding nearly $400 million in military aid for its war against Russian-backed separatists and a White House meeting for Zelensky until the latter announced a Biden probe.
- 'Nothing wrong' -
"The president did nothing wrong," Trump's lawyers responded in a 110-page brief submitted to the Senate on Monday.
This echoes the repeated assertions of the 73-year-old real estate magnate that the saga is a political witch hunt and a hoax, and that his phone call with the Ukrainian leader was "perfect."
In the president's brief, his 12-man legal team contested the very idea of his impeachment.
They called the two articles of impeachment -- approved largely along party lines in the Democratic-controlled House -- the product of "a rigged process" and "constitutionally deficient on their face" because they involved no violation of established law.
That team, which has recruited high profile lawyers such as Kenneth Starr, who tried to bring down Clinton over his affair with Monica Lewinsky, said in the brief, "The Senate should reject the Articles of Impeachment and acquit the president immediately."
- 'Worst nightmare' -
"President Trump abused the power of his office to solicit foreign interference in our elections for his own personal political gain, thereby jeopardizing our national security, the integrity of our elections, and our democracy," the House managers said Saturday in a memorandum.
They said the president's behavior "is the Framers' worst nightmare," referring to the authors of the US Constitution, and that Trump deserves to be removed from office.
But Trump looks almost certain to be acquitted because of the 53-47 Republican majority in the Senate.
He will be abroad as his trial opens; Trump left late Monday for the economic forum in Davos, Switzerland.
How long the trial will last is up in the air.
The first order of business Tuesday will be to set the rules, such as how long they will hear the arguments of the House managers, or prosecutors; how long they will hear the defense; the time allotted for questions, submitted by the senators but read by Roberts; and whether they will call witnesses or seek other evidence.
Senate Majority Leader Mitch McConnell late Monday proposed rules calling for each side to have 24 hours over two days to present their arguments. That makes for long trial days stretching late into the night but is a significantly quicker pace than in Bill Clinton's impeachment trial in 1999. The chamber will debate and vote on the proposed rules Tuesday.
Senate Democratic leader Chuck Schumer said McConnell is rushing the trial and also making it harder for witnesses and documents to be presented.
"On something as important as impeachment, Senator McConnell's resolution is nothing short of a national disgrace," Schumer said in a statement.
The Democrats want key Trump administration officials to testify, such as acting chief of staff Mick Mulvaney and former national security adviser John Bolton, in the belief that they know a lot about Trump's dealings with Ukraine. Bolton has said he is willing to testify if subpoenaed.
The White House has said it expects the trial to be over in two weeks. Clinton's trial lasted five weeks.
McConnell has said he won't consider the witness issue until after the arguments and questioning take place, and his majority means he will likely prevail.
You can watch the Senate trial and additional coverage below:
US President Donald Trump arrived in Davos on Tuesday for the annual WEF forum, where he was to give a keynote speech just hours before his impeachment trial kicks into high gear in Washington.
Trump's Marine One helicopter touched down in the picturesque Swiss ski resort shortly ahead of his scheduled speech to the World Economic Forum, which this year is focusing on climate change.
He was also due to meet separately with the president of Iraq, Pakistan's prime minister and the head of the European Union executive body.
Meanwhile in Washington, Trump's impeachment enters a new phase in the Senate with legislators debating the format for the trial.
Although Trump's Republican party holds a majority in the Senate and is almost sure to acquit him on charges of abusing his power and obstructing Congress, the impeachment adds volatility to an already tense 2020 presidential election.
Democrats are poised to hold a vote in the House of Representatives on Thursday to "terminate" President Donald Trump's ability to wage war against Iran.
The resolution was written by Rep. Elissa Slotkin (D-MN), who was a CIA analyst and worked for the Director of National Intelligence before running for office.
"Congress has not authorized the President to use military force against Iran," the resolution reads.
The resolution says, "Congress hereby directs the President to terminate the use of United States Armed Forces to engage in hostilities in or against Iran or any part of its government or military" unless Congress declares war or there is "an imminent armed attack."
"Today, to honor our duty to keep the American people safe, the House will move forward with a War Powers Resolution to limit the President’s military actions regarding Iran. This resolution, which will be led by Congresswoman Elissa Slotkin, will go to the Rules Committee this evening and will be brought to the Floor tomorrow," Pelosi announced on Wednesday.
Republicans have worked to undermine and attack witnesses, particularly the whistleblower who filed a complaint alerting Congress President Donald Trump was using military funds to Ukraine to demand they open an investigation into former Vice President Joe Biden.
When speaking to MSNBC about the hearing, former U.S. Ambassador to Russia Michael McFaul went off on Trump's allies, who are working to attack the integrity of the veteran.
"First, I know Colonel Vindman; we served together in Moscow," McFaul said. "He was a military attaché there. A first-rate officer, knows Russia, knows Ukraine. One of the best and the brightest. And when I hear this disparagement of him by some people allegedly claiming this might be an allegation of espionage, it really angers me."
McFaul called the claim outrageous for Republicans to destroy a soldier that spoke out only because he took his sense of duty seriously.
"It is outrageous, and it needs to stop," an angry McFaul told MSNBC. "This is somebody who has served on the battlefield and off. You can disagree with his actions, and we can talk about that, but you cannot attack his integrity, and you certainly cannot slander him because of his ethnicity. It really bothers me. Sorry."
McFaul said that Vindman was reaffirming what was already known and revealed by both the whistleblower and the White House summary of the Ukraine call.
"He happened to be on the call, and what you have here is just clear as day, it is the use of a public office, in this case, the Oval Office, the president of the United States, for private personal gain in his reelection efforts for 2020," he continued. "It's just clear as day. There should be no argument about what the facts are. The argument is whether that's right or wrong and an impeachable offense or not, but the facts are clear, and Col. Vindman is adding more detail to what we already know."
British MPs are gathering for an extraordinary session of parliament on Saturday to debate and subsequently vote on the Brexit deal that Prime Minister Boris Johnson made with the EU.
British MPs gather Saturday for a historic vote on Prime Minister Boris Johnson's Brexit deal - a decision that could see the UK leave the EU this month or plunge the country into fresh uncertainty.
The vote is widely seen as too close to call but Johnson warned his deal was still the best way out of the tortuous Brexit process that has left Britain in political turmoil since 2016.
"There is no better outcome than the one I'm advocating," he told the BBC on Friday evening, calling it a "fantastic deal for all of the UK".
Securing a deal was a personal victory for Johnson, a "Vote Leave" leader in the referendum campaign who has vowed to deliver Brexit on October 31 in all circumstances.
But parliament -—like the frustrated public—- is still divided over how and even if Britain should end 46—years of integration with its closest neighbours.
The debate starts from 0830 GMT and coincides with a mass demonstration to parliament demanding a "People's Vote", with an option to reverse Brexit.
If the deal passes, Johnson is expected to introduce legislation on Monday to ratify the text, which must be pushed through before the end of the month.
He insists that Brexit must happen this month to end to uncertainty that has weighed on the economy and dominated political and public debate.
But his political situation is more fragile than May's, after he expelled 21 of his own Conservative MPs who refused to accept his threat to leave the EU with no deal.
Businesses and markets on both sides of the Channel fear a disorderly exit, and EU leaders have twice delayed Brexit already to avoid such an outcome.
Some of the Tory rebels are supporting an amendment on Saturday asking MPs to back the deal only on condition that it is ratified before Britain leaves the EU.
Johnson could also face opposition from eurosceptics who fear his deal will not fulfil their dreams of abolishing decades of EU rules and regulations from British life.
Northern Ireland's Democratic Unionist Party, which props up Johnson's minority government, will vote against it because of its arrangements for the British province.
The main opposition Labour party meanwhile warns the deal could lead to only a loose trading relationship with the EU after Brexit, which could damage the economy and lower environmental and labour standards.
No extension
EU leaders in Brussels this week urged lawmakers to back the deal, to allow both sides to move on to discussing their future relationship.
"This deal means there is no need for any kind of prolongation," European Commission President Jean-Claude Juncker said.
Rejecting the deal would create an "extremely complicated situation", he added.
The deal covers Britain's financial settlement, protects the rights of EU citizens and sets out a post-Brexit transition period potentially until 2022 to allow both sides to agree new trade terms.
The most controversial element relates to arrangements to keep open the border between British Northern Ireland and EU member Ireland.
The previous "backstop" plan, which could have kept Britain in the EU's customs union potentially indefinitely, has been replaced by a new system that will allow London to strike its own trade deals.
But there would be new checks on trade between Northern Ireland and mainland Britain, to the outrage of the DUP.
Archaeologists are set to unveil the answer to a 200-year-old question over the remains of a French general who died during Napoleon's 1812 campaign in Russia.
Charles Etienne Gudin was hit by a cannonball in the Battle of Valutino on August 19 near Smolensk, a city west of Moscow close to the border with Belarus.
His leg was amputated and he died three days later from gangrene, aged 44.
The French army cut out his heart, now buried at the Pere Lachaise cemetery in Paris, but the site of the rest of his remains was never known, until researchers found a likely skeleton this summer.
"As soon as I saw the skeleton with just one leg, I knew that we had our man," the head of the Franco-Russian team that discovered the remains in July, Marina Nesterova, told AFP.
Genetic analysis is being carried out to confirm the identity, using DNA from one of the general's descendants, with the results to be announced on Thursday.
Gudin is said to have been one of Napoleon's favourite generals and the two men attended military school together. His name is engraved on the Arc de Triomphe monument in Paris.
The fresh search for his remains has been underway since May, funded by a Franco-Russian group headed by Pierre Malinowski, a historian and former soldier with ties to the French far-right and support from the Kremlin.
The team in Smolensk first followed the memoirs of a subordinate of Gudin, Marshall Davout, who organised the funeral and described a mausoleum made of four cannon barrels pointing upward, said Nikolai Makarov, the director of the Russian Institute of Archaeology.
When that trail ran cold, they checked another theory by a witness of the funeral and found pieces of a wooden casket buried under an old dance floor in the city park.
A preliminary report concluded that the skeleton belonged to a man who died aged 40-45.
Gudin's death near Smolensk came near the beginning of Napoleon's march toward Moscow, 400 kilometres (250 miles) further east.
Napoleon had hoped to defeat the Russian army at Valutino and sign an advantageous treaty, but it managed to escape and Russian Tsar Alexander refused to discuss peace.
"This battle could have been decisive if Napoleon hadn't underestimated the Russians," Malinowski said.
"Heavy losses in this battle showed Napoleon that he was going to go through hell in Russia."
Napoleon's march on Russia ended in a disastrous retreat as Russians used scorched earth tactics and even ordered Moscow to be burnt to sap Napoleon's resources.
Less than 10 percent of his Grand Armee survived Russian invasion.
US President Donald Trump will address the nation on Monday after two shootings left 29 people dead and sparked accusations that his rhetoric was part of the problem.
The rampages turned innocent snippets of everyday life into nightmares of bloodshed: 20 people were shot dead while shopping at a crowded Walmart in El Paso, Texas on Saturday morning, and nine more outside a bar in a popular nightlife district in Dayton, Ohio just 13 hours later.
Trump will again find himself in the role of consoler-in-chief after a tragedy -- which he has struggled with in the past -- when he speaks at 10:00 am (1400 GMT).
Following the shootings, Trump said "hate has no place in our country," but he also blamed mental illness for the violence.
"These are really people that are very, very seriously mentally ill," he said, despite the fact that police have not confirmed this to be the case.
"We have to get it stopped. This has been going on for years... and years in our country," he said.
In Texas, 26 people were wounded, and 27 in Ohio, where the shooter was killed in roughly 30 seconds by police who were patrolling nearby.
- 100-round drum magazine -
Dayton Police Chief Richard Biehl told a news conference that the quick police response was "crucial," preventing the shooter from entering a bar where "there would have been... catastrophic injury and loss of life."
Biehl said the shooter wore a mask and a bullet-proof vest and was armed with an assault rifle fitted with a 100-round drum magazine.
Police named the gunman as a 24-year-old white man called Connor Betts and said his sister was among those killed. She had gone with him to the scene of the shootings.
Six of the nine people shot dead were black, but Biehl said Betts' motive was still unclear.
In Texas, police said the suspect surrendered on a sidewalk near the scene of the massacre. He was described in media reports as a 21-year-old white man named Patrick Crusius.
He was believed to have posted online a manifesto denouncing a "Hispanic invasion" of Texas. El Paso, on the border with Mexico, is majority Latino.
- 'Amplifying and condoning' hate -
Seven of the 20 people killed in the El Paso shooting were Mexican, the country's foreign minister, Marcelo Ebrard, said Sunday.
Ebrard, who will travel to El Paso Monday, said Mexico was looking at legal action which could lead to extradition of the gunman.
"For Mexico, this individual is a terrorist," he said.
The manifesto posted shortly before the shooting also praises the killing of 51 Muslims at two mosques in Christchurch, New Zealand in March.
Police said the suspected shooter has been charged with murder offenses that can carry the death penalty, and a federal official said investigators are treating the El Paso shooting as a case of domestic terrorism.
At the Walmart in El Paso, terrified shoppers cowered in aisles or ran out of the store as gunfire echoed.
Most of the victims were inside the store but some were also in the parking lot outside, police said.
"Shooting kids and women and men, to him it mostly mattered that they were Hispanic," said Manuel Sanchez, a resident of the city.
These were the 250th and 251st mass shootings this year in the US, according to the Gun Violence Archive, an NGO that defines a mass shooting as an incident in which at least four people are wounded or killed.
Despite a string of horrific mass shootings in the US, where gun culture is deep-rooted, efforts to strengthen firearms regulations remain divisive.
The latest two shootings ended a particularly tragic week for gun violence in America: three people died in a shooting at a food festival last Sunday in California, and two more Tuesday in a shooting in a Walmart in Mississippi.
On Twitter, Trump described the El Paso attack as "an act of cowardice."
But critics said the president's habit of speaking in derogatory terms about immigrants is pushing hatred of foreigners into the political mainstream and encouraging white supremacism.
"To pretend that his administration and the hateful rhetoric it spreads doesn't play a role in the kind of violence that we saw yesterday in El Paso is ignorant at best and irresponsible at worst," said the Southern Poverty Law Center, a major civil rights group.
It cited Trump actions like calling Mexican migrants rapists and drug dealers and doing nothing when a crowd at a Trump rally chanted "send her back" in reference to a Somali-born congresswoman.
The Republican mayor of El Paso, Dee Margo, seemed to discount any race element to the Texas shooting, telling Fox News the gunman was "deranged."
But multiple Democratic presidential hopefuls said Trump bears some of the blame for the violence.
"Our president isn't just failing to confront and disarm these domestic terrorists, he is amplifying and condoning their hate," Mayor Pete Buttigieg tweeted.
"Mr. President: stop your racist, hateful and anti-immigrant rhetoric. Your language creates a climate which emboldens violent extremists," Senator Bernie Sanders wrote on Twitter.
US President Donald Trump will address the nation on Monday after two shootings left 29 people dead and sparked accusations that his rhetoric was part of the problem.
The rampages turned innocent snippets of everyday life into nightmares of bloodshed: 20 people were shot dead while shopping at a crowded Walmart in El Paso, Texas on Saturday morning, and nine more outside a bar in a popular nightlife district in Dayton, Ohio just 13 hours later.
Trump will again find himself in the role of consoler-in-chief after a tragedy -- which he has struggled with in the past -- when he speaks at 10:00 am (1400 GMT).
Following the shootings, Trump said "hate has no place in our country," but he also blamed mental illness for the violence.
"These are really people that are very, very seriously mentally ill," he said, despite the fact that police have not confirmed this to be the case.
"We have to get it stopped. This has been going on for years... and years in our country," he said.
In Texas, 26 people were wounded, and 27 in Ohio, where the shooter was killed in roughly 30 seconds by police who were patrolling nearby.
- 100-round drum magazine -
Dayton Police Chief Richard Biehl told a news conference that the quick police response was "crucial," preventing the shooter from entering a bar where "there would have been... catastrophic injury and loss of life."
AFP / Megan JELINGER Shoes belonging to victims of the shooting outside Ned Peppers bar, in Dayton, Ohio, are piled after a gunman armed with an assault rifle killed nine people
Biehl said the shooter wore a mask and a bullet-proof vest and was armed with an assault rifle fitted with a 100-round drum magazine.
Police named the gunman as a 24-year-old white man called Connor Betts and said his sister was among those killed. She had gone with him to the scene of the shootings.
Six of the nine people shot dead were black, but Biehl said Betts' motive was still unclear.
In Texas, police said the suspect surrendered on a sidewalk near the scene of the massacre. He was described in media reports as a 21-year-old white man named Patrick Crusius.
He was believed to have posted online a manifesto denouncing a "Hispanic invasion" of Texas. El Paso, on the border with Mexico, is majority Latino.
- 'Amplifying and condoning' hate -
Seven of the 20 people killed in the El Paso shooting were Mexican, the country's foreign minister, Marcelo Ebrard, said Sunday.
Ebrard, who will travel to El Paso Monday, said Mexico was looking at legal action which could lead to extradition of the gunman.
"For Mexico, this individual is a terrorist," he said.
AFP / Megan JELINGER A couple mourn at a vigil for victims of the shooting in Dayton, Ohio, which killed nine people 13 hours after another gunman in El Paso, Texas, murdered 29 people
The manifesto posted shortly before the shooting also praises the killing of 51 Muslims at two mosques in Christchurch, New Zealand in March.
Police said the suspected shooter has been charged with murder offenses that can carry the death penalty, and a federal official said investigators are treating the El Paso shooting as a case of domestic terrorism.
At the Walmart in El Paso, terrified shoppers cowered in aisles or ran out of the store as gunfire echoed.
Most of the victims were inside the store but some were also in the parking lot outside, police said.
AFP / Mark RALSTON A reporter for Spanish-language Telemundo breaks down beside a makeshift memorial outside the Cielo Vista Mall Wal-Mart (background) in El Paso, Texas, where a shooting left 20 people dead, including six Mexicans
"Shooting kids and women and men, to him it mostly mattered that they were Hispanic," said Manuel Sanchez, a resident of the city.
These were the 250th and 251st mass shootings this year in the US, according to the Gun Violence Archive, an NGO that defines a mass shooting as an incident in which at least four people are wounded or killed.
Despite a string of horrific mass shootings in the US, where gun culture is deep-rooted, efforts to strengthen firearms regulations remain divisive.
The latest two shootings ended a particularly tragic week for gun violence in America: three people died in a shooting at a food festival last Sunday in California, and two more Tuesday in a shooting in a Walmart in Mississippi.
On Twitter, Trump described the El Paso attack as "an act of cowardice."
But critics said the president's habit of speaking in derogatory terms about immigrants is pushing hatred of foreigners into the political mainstream and encouraging white supremacism.
AFP / Kun TIAN Major mass shootings in the United States since 2012
"To pretend that his administration and the hateful rhetoric it spreads doesn't play a role in the kind of violence that we saw yesterday in El Paso is ignorant at best and irresponsible at worst," said the Southern Poverty Law Center, a major civil rights group.
It cited Trump actions like calling Mexican migrants rapists and drug dealers and doing nothing when a crowd at a Trump rally chanted "send her back" in reference to a Somali-born congresswoman.
The Republican mayor of El Paso, Dee Margo, seemed to discount any race element to the Texas shooting, telling Fox News the gunman was "deranged."
AFP / Nicholas Kamm Critics of Trump say his habit of speaking in derogatory terms about immigrants encourages white supremacists
But multiple Democratic presidential hopefuls said Trump bears some of the blame for the violence.
"Our president isn't just failing to confront and disarm these domestic terrorists, he is amplifying and condoning their hate," Mayor Pete Buttigieg tweeted.
"Mr. President: stop your racist, hateful and anti-immigrant rhetoric. Your language creates a climate which emboldens violent extremists," Senator Bernie Sanders wrote on Twitter.
Democratic presidential candidate Julián Castro reacted to the weekend mass shootings in El Paso, Texas and Dayton, Ohio by knocking down the conservative premise that a "good guy with a gun" can stop the violence.
In an interview on CNN, Castro said that President Donald Trump is "making it worse" by "fanning the flames of bigotry and of hate."
The candidate also blasted the NRA's talking points.
"The NRA, for years, has said that the answer to these mass shootings is more guns, that a good guy with a gun is the answer," Castro added. "We’re in Texas. That shooter went into a situation where people routinely carry guns."
"Concealed carry is allowed here. Open carry is allowed here. Campus carry is allowed here," he continued. "He knew that he was going into a Walmart with 1,000 or 2,000 people in it. Certainly people are packing. That didn’t deter him. And it didn’t keep those people safe."
Coffee is unique among artisanal beverages in that the brewer plays a significant role in its quality at the point of consumption. In contrast, drinkers buy draft beer and wine as finished products; their only consumer-controlled variable is the temperature at which you drink them.
Why is it that coffee produced by a barista at a cafe always tastes different than the same beans brewed at home?
It may be down to their years of training, but more likely it’s their ability to harness the principles of chemistry and physics. I am a materials chemist by day, and many of the physical considerations I apply to other solids apply here. The variables of temperature, water chemistry, particle size distribution, ratio of water to coffee, time and, perhaps most importantly, the quality of the green coffee all play crucial roles in producing a tasty cup. It’s how we control these variables that allows for that cup to be reproducible.
How strong a cup of joe?
Besides the psychological and environmental contributions to why a barista-prepared cup of coffee tastes so good in the cafe, we need to consider the brew method itself.
We humans seem to like drinks that contain coffee constituents (organic acids, Maillard products, esters and heterocycles, to name a few) at 1.2 to 1.5 percent by mass (as in filter coffee), and also favor drinks containing 8 to 10 percent by mass (as in espresso). Concentrations outside of these ranges are challenging to execute. There are a limited number of technologies that achieve 8 to 10 percent concentrations, the espresso machine being the most familiar.
There are many ways, though, to achieve a drink containing 1.2 to 1.5 percent coffee. A pour-over, Turkish, Arabic, Aeropress, French press, siphon or batch brew (that is, regular drip) apparatus – each produces coffee that tastes good around these concentrations. These brew methods also boast an advantage over their espresso counterpart: They are cheap. An espresso machine can produce a beverage of this concentration: the Americano, which is just an espresso shot diluted with water to the concentration of filter coffee.
All of these methods result in roughly the same amount of coffee in the cup. So why can they taste so different?
When coffee meets water
There are two families of brewing device within the low-concentration methods – those that fully immerse the coffee in the brew water and those that flow the water through the coffee bed.
From a physical perspective, the major difference is that the temperature of the coffee particulates is higher in the full immersion system. The slowest part of coffee extraction is not the rate at which compounds dissolve from the particulate surface. Rather, it’s the speed at which coffee flavor moves through the solid particle to the water-coffee interface, and this speed is increased with temperature.
The Coffee Taster’s Flavor Wheel provides a way to name various tastes within the beverage.
Specialty Coffee Association of America, CC BY-NC-ND
A higher particulate temperature means that more of the tasty compounds trapped within the coffee particulates will be extracted. But higher temperature also lets more of the unwanted compounds dissolve in the water, too. The Specialty Coffee Association presents a flavor wheel to help us talk about these flavors – from green/vegetative or papery/musty through to brown sugar or dried fruit.
Pour-overs and other flow-through systems are more complex. Unlike full immersion methods where time is controlled, flow-through brew times depend on the grind size since the grounds control the flow rate.
The water-to-coffee ratio matters, too, in the brew time. Simply grinding more fine to increase extraction invariably changes the brew time, as the water seeps more slowly through finer grounds. One can increase the water-to-coffee ratio by using less coffee, but as the mass of coffee is reduced, the brew time also decreases. Optimization of filter coffee brewing is hence multidimensional and more tricky than full immersion methods.
Even if you can optimize your brew method and apparatus to precisely mimic your favorite barista, there is still a near-certain chance that your home brew will taste different from the cafe’s. There are three subtleties that have tremendous impact on the coffee quality: water chemistry, particle size distribution produced by the grinder and coffee freshness.
First, water chemistry: Given coffee is an acidic beverage, the acidity of your brew water can have a big effect. Brew water containing low levels of both calcium ions and bicarbonate (HCO₃⁻) – that is, soft water – will result in a highly acidic cup, sometimes described as sour. Brew water containing high levels of HCO₃⁻ – typically, hard water – will produce a chalky cup, as the bicarbonate has neutralized most of the flavorsome acids in the coffee.
Ideally we want to brew coffee with watercontaining chemistry somewhere in the middle. But there’s a good chance you don’t know the bicarbonate concentration in your own tap water, and a small change makes a big difference. To taste the impact, try brewing coffee with Evian – one of the highest bicarbonate concentration bottled waters, at 360 mg/L.
The particle size distribution your grinder produces is critical, too.
Every coffee enthusiast will rightly tell you that blade grinders are disfavored because they produce a seemingly random particle size distribution; there can be both powder and essentially whole coffee beans coexisting. The alternative, a burr grinder, features two pieces of metal with teeth that cut the coffee into progressively smaller pieces. They allow ground particulates through an aperture only once they are small enough.
There is contention over how to optimize grind settings when using a burr grinder, though. One school of thought supports grinding the coffee as fine as possible to maximize the surface area, which lets you extract the most delicious flavors in higher concentrations. The rival school advocates grinding as coarse as possible to minimize the production of fine particles that impart negative flavors. Perhaps the most useful advice here is to determine what you like best based on your taste preference.
Finally, the freshness of the coffee itself is crucial. Roasted coffee contains a significant amount of CO₂ and other volatiles trapped within the solid coffee matrix: Over time these gaseous organic molecules will escape the bean. Fewer volatiles means a less flavorful cup of coffee. Most cafes will not serve coffee more than four weeks out from the roast date, emphasizing the importance of using freshly roasted beans.
One can mitigate the rate of staling by cooling the coffee (as described by the Arrhenius equation). While you shouldn’t chill your coffee in an open vessel (unless you want fish finger brews), storing coffee in an airtight container in the freezer will significantly prolong freshness.
So don’t feel bad that your carefully brewed cup of coffee at home never stacks up to what you buy at the café. There are a lot of variables – scientific and otherwise – that must be wrangled to produce a single superlative cup. Take comfort that most of these variables are not optimized by some mathematicalalgorithm, but rather by somebody’s tongue. What’s most important is that your coffee tastes good to you… brew after brew.
AFP / Megan JELINGER 
AFP / Megan JELINGER 
AFP / Mark RALSTON 
AFP / Kun TIAN 
AFP / Nicholas Kamm 
