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Stories from the kitchen,
backed by the data.
Coffee Water Hardness and pH: What the Numbers Mean and How to Check Yours
SCA targets for brewing water are 150 ppm TDS, about 4 grains of hardness and pH 7, but sources disagree on the ranges. Learn to read your report and test.
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Coffee and Depression: What Two Meta-Analyses and a 50,000-Woman Study Show
Higher coffee intake is linked to lower depression risk in a 2011 study of 50,739 women and two 2016 meta-analyses. See the numbers and what they cannot prove.
Coffee and Gout: What the Studies Say and What They Cannot Tell You
A 12-year study of 45,869 men and a 2016 meta-analysis link coffee to lower gout risk. See the numbers, the decaf result and why it is not a treatment.
Coffee and Sleep: How Late Is Too Late, According to the Research
A 24-study meta-analysis found caffeine cut sleep by 45 minutes on average. See the cutoff times researchers suggest and how to work out your own.
Coffee and Heart Health: Palpitations, Heart Rate, AF and Heart Disease
In the DECAF trial, AF patients told to drink coffee relapsed less (47% vs 64%). See what trials and big cohorts say on palpitations, heart rate and disease.
Coffee and IBS: What the Studies Say and How to Test Your Own Trigger
Heavy caffeine carried 47 percent higher odds of IBS in a 3,362-adult study, and dietitians advise capping tea and coffee at three. Test your own trigger.
Coffee and ADHD: Does Caffeine Help Focus? What the Trials Actually Show
A 2023 meta-analysis of caffeine trials in children with ADHD found no significant benefit over placebo. Here is what the evidence does and does not say.
How Much Caffeine Is in a Latte and a Chai Latte? Shots, Size and Syrup
A latte's caffeine follows its espresso shots, not its cup size, and a chai latte can hold anywhere from none to about 60 mg. Here is the arithmetic.
Coffee and Iron Absorption: What the Studies Show and How to Time Your Cup
Coffee with a meal cut iron absorption by 39 percent in a classic study, yet coffee an hour before eating did not. What the data show and how to time it.
Coffee and Kidney Health: What the Genetic and Pooled Studies Show
Genetic data from 227,666 people and two pooled analyses link coffee to lower chronic kidney disease risk. What the numbers show and where they stop.
Coffee and Migraines: Trigger, Treatment or Both? What the Studies Show
Coffee can ease a migraine or set one off. A 98-person diary study, a withdrawal trial and a Cochrane review show where the line sits and what to do.
Espresso Grind Size by Machine and Grinder: Why the Setting Belongs to the Grinder
Searching for an espresso grind setting for your machine? Sourced starting points for three grinders, plus why the number never transfers.
Coffee and Weight Loss: What the Trials and Meta-Analyses Actually Show
Does coffee help you lose weight? A 24-week trial, two meta-analyses and the calorie math on what goes in the cup, with the effect sizes and caveats.
Coffee and Liver Health: What the Cirrhosis, Fibrosis and Liver Cancer Studies Show
Coffee drinkers have lower rates of cirrhosis and chronic liver disease in large studies. What the numbers show, which results are weaker, and what to ask.
How Much Caffeine Is in an Espresso Martini? The Math by Recipe
An espresso martini holds about 65 to 130mg of caffeine, almost all from the espresso. Per-recipe math, the Kahlua figure, and how to count it toward 400mg.
How Much Caffeine Is in Starbucks Bottled and Canned Drinks? Doubleshot, Frappuccino and More
Bottled Starbucks drinks run from 45mg to 375mg of caffeine. Per-ounce math for Doubleshot Energy, Frappuccino, Iced Espresso and Refreshers, and source gaps.
Matcha vs Coffee Caffeine: Why Per-Gram and Per-Cup Answers Disagree
Matcha has 19 to 44mg of caffeine per gram, coffee beans 10 to 12. Yet cups land close together. Here is the per-scoop math, a table, and a 400mg plan.
How Much Caffeine Is in Blue Bottle Coffee? What the Company Tests and What It Doesn't
Blue Bottle publishes caffeine for four canned and boxed drinks, 170 to 234mg, and tests nothing else. Per-ounce math, a 400mg day plan, and the gaps.
How Much Caffeine Is in 7-Eleven Coffee? What the Lab Test Found
7-Eleven brewed coffee averaged 280mg in a 2017 lab test, at 19 to 22mg an ounce in New York stores. Size math, chain comparisons and the data gaps.
AeroPress Inverted vs Standard: Which Method Fits Which Cup, and What the Champions Actually Use
Standard and inverted AeroPress brew the same coffee in different ways: drip-through, steep control, flip risk. See both with real champion recipes.
Coffee and Dementia: What the 43-Year Harvard Study Found, and Why Decaf Didn't Show the Effect
A 2026 JAMA study of 131,821 people over up to 43 years linked 2-3 cups of caffeinated coffee to 18% lower dementia risk. Decaf showed nothing.
Coffee and Cholesterol: Why the Brew Method Matters More Than the Cup Count
Paper-filtered coffee barely moves LDL, while French press and boiled coffee raise it. What the trials show, and how to brew around the problem.
How Much Caffeine Is in Caribou Coffee? Brewed, Depth Charge and Cans
A medium Caribou brewed coffee carries 305mg and a large Depth Charge 445mg, past the FDA's 400mg reference. Full size-by-size figures and cans.
How Much Caffeine Is in La Colombe? Draft Latte, Triple and Cold Brew
La Colombe's canned cold brew lists 180mg per 9 oz, while its draft lattes range from 100mg to 175mg depending on the flavor and the year of the can.
What Is Mushroom Coffee, and Does It Actually Do Anything?
Mushroom coffee evidence rests on small lion's mane supplement trials, not coffee blends, and chaga carries a documented kidney risk. Here is what holds up.
What Is Bulletproof Coffee, and Does It Actually Do Anything?
A Walter Reed-sponsored trial found 12 weeks of butter and MCT oil in coffee did not raise LDL, but a 2023 review found no proven focus or energy benefit.
Coffee and Gut Health: What the Research Actually Shows
A 2024 study of 22,867 people found coffee drinkers carry up to eight times more of one gut bacterium, an effect that holds, though weaker, for decaf.
Coffee and Intermittent Fasting: Does It Actually Break a Fast?
A mouse study found coffee triggers autophagy within hours, but a small human trial of fasting black coffee found no change in glucose or triglycerides.
Coffee and Testosterone: Does It Raise or Lower It?
A 2,264-person Finnish cohort found coffee raises men's total testosterone, but also raises SHBG, which lowers the testosterone the body can actually use.
Coffee and Diabetes: What the Evidence Actually Says
A 1.1 million person meta-analysis found coffee cuts type 2 diabetes risk 9% per cup, yet a controlled trial found caffeine raises post-meal glucose 21%.
How Much Caffeine Is in Dutch Bros Coffee? Rebel, 911, Cold Brew and More
A large Dutch Bros coffee carries 187mg, the 911 holds 280.5mg at every size, and the cold brew can packs 293mg, per Caffeine Informer's figures.
Japanese Iced Coffee: Ratio, Method, and Which Dripper to Use
Japanese iced coffee ratios split two ways: about 1:10 by poured water, 1:15 to 1:20 by total liquid. Here is why, plus the grind and method by dripper.
Coffee and Blood Pressure: What the Evidence Actually Says
Caffeine raises blood pressure about 8 over 6 mmHg within an hour, yet a 463,973-person analysis found habitual coffee does not raise hypertension risk.
Caffeine Withdrawal: Symptoms, Timeline, and How Long It Actually Lasts
Caffeine withdrawal starts within 12 to 24 hours, peaks by day two, and is a real DSM-5 diagnosis. Here is the actual timeline, and what tapering changes.
Coffee and Cortisol: Does It Actually Spike Your Stress Hormone?
A 96-person trial found caffeine raises cortisol after abstinence, but daily drinkers build partial tolerance within days. Here is the real dose picture.
Coffee and Anxiety: What the Evidence Actually Says
A meta-analysis of 546 people found caffeine's anxiety effect is moderate under 400mg and severe above it. Here is the real dose curve, and who is most at risk.
How to Descale an Espresso Machine: Frequency, Vinegar vs Citric Acid, and the Full Process
Descaling frequency depends on water hardness, not a fixed calendar. Here is citric acid versus vinegar, real ratios, and the full step-by-step process.
Clever Dripper: Ratio, Grind Size, and How It Compares to a V60
The Clever Dripper ratio splits 1:15 to 1:16 across three sourced guides. Here is the grind, the full brew steps, and how it compares to a V60 and Hario Switch.
Vietnamese Coffee (Phin): Ratio, Grind Size, and How to Use One
The phin ratio runs 1:2 to 1:8 depending on the source. Here is why the gap is real, the grind size that works, and the full step-by-step brewing method.
How Much Caffeine Is in Starbucks Nitro Cold Brew? Why There Is No Venti Size
A Grande Starbucks Nitro Cold Brew carries 280mg of caffeine, and Starbucks caps the drink at Grande because a Venti would land near 430mg.
How Much Caffeine Is in Costa Coffee? The UK Chain That Out-Doses Starbucks
Costa's medium cappuccino carries 325mg of caffeine, per an August 2026 Which? test, almost three and a half times Starbucks' 89mg at the same size.
How Much Caffeine Is in Peet's Coffee? The Official Numbers by Roast, Shot, and Size
Peet's own brewed coffee hits 267mg in a 16oz cup, and its blog reports roast level moves caffeine by about one percentage point, from 1.08% to 1.17%.
How Much Caffeine Is in Panera Coffee? The Official Numbers, by Size and Roast
Panera's own March 2026 guide puts a 16oz coffee at 189mg no matter the roast, and ordering iced with no ice nearly doubles the caffeine in the cup.
Percolator Coffee: Ratio, Grind Size, and How to Use One
The percolator ratio is one tablespoon of coarse grounds per cup of water. Here is the grind size and the heat control that stops it turning bitter.
Does Coffee Cause Acid Reflux, or Is That a Myth?
Coffee relaxes the lower esophageal sphincter and GERD affects 1 in 5 Americans. Here is the real mechanism, what actually helps, and what does not.
Coffee Before a Workout: Does It Actually Help Performance?
A 2012 gene study found caffeine cut 40km cycling times 4.9% in fast metabolizers, 1.8% in slow ones. Here is the real dose, timing, and genetics.
Americano vs Long Black vs Filter Coffee: What Is Actually Different
The Americano pours espresso first, then water, stripping the crema. The Long Black reverses the order and keeps it. Here is what that actually changes.
How Much Caffeine Is Really in Decaf Coffee?
A 2006 lab test found Starbucks grande decaf at 12 to 13.4mg, about half the 25mg Starbucks itself lists. Here is what decaf actually contains.
Coffee on an Empty Stomach: Benefits, Risks, and Why It Makes Some People Nauseous
An 8,000-person Japanese study found no ulcer link. Cleveland Clinic and Healthline agree on what coffee on an empty stomach actually does to you.
Is Coffee a Laxative? What the Evidence Actually Says
A 1990 study found only 29 percent of coffee drinkers feel the urge to go. A meta-analysis of 432,000 people found coffee actually lowers IBS risk overall.
Cortado vs Flat White vs Cappuccino vs Latte vs Macchiato: Every Espresso Drink Compared
Two sourced guides put the flat white at roughly 1:2.5 to 1:4 milk to espresso. A third claims the opposite. Here is the real ratio for all five drinks.
Espresso Dose Ratio: How Much Coffee In, How Much Espresso Out
Four sourced guides agree on an 18g to 36g, 1:2 normale ratio, but disagree on where ristretto ends and lungo begins. Both readings, reconciled.
How Much Caffeine Is in Tim Hortons Coffee? Every Size, By the Numbers
Tim Hortons published caffeine figures back in 2008: 140mg small to 330mg extra-large brewed coffee. Espresso and lattes split sharply by country, though.
Pour-Over Coffee to Water Ratio and Grind Size: The Complete Guide
Three sourced guides converge on a 1:16 to 1:17 ratio for a V60 pour-over, with medium-fine grind, bloom timing, and a staged pour schedule explained.
Cold Brew Coffee to Water Ratio and Grind Size: The Complete Guide
Three sourced guides converge on a 1:8 concentrate ratio for cold brew, with the coarse grind, dilution step, and steep time by temperature explained.
How Much Caffeine Is in a K-Cup? The Real Range, By Size
Two independent trackers agree: a standard K-Cup runs 75 to 125mg of caffeine. The cup-size button changes dilution, not the fixed dose in the pod.
How Much Caffeine Is in Dunkin' Coffee? Every Size, By the Numbers
Dunkin' publishes an approximate caffeine range, unlike some chains. Two trackers confirm the size-by-size numbers: 180mg small to 330mg extra-large hot coffee.
Moka Pot Coffee to Water Ratio and Grind Size: The Complete Guide
Two sourced guides reconcile to 1:7 to 1:8 by weight for moka pot, with gram doses by pot size, the right grind texture, and a full brewing routine.
How Much Caffeine Is in McDonald's Coffee? Every Size, By the Numbers
McDonald's has never officially published its coffee's caffeine content. Two independent trackers agree closely: 109mg small, 145mg medium, 180mg large.
How to Store Coffee Beans: The Right Container, and Why the Fridge Isn't It
Two sourced guides agree: opaque, airtight, and never the fridge. Here is the reconciled container setup, the valve question, and what actually degrades beans.
The Best Water Temperature for Coffee, and Why Roast Level Changes It
The specialty standard is 195 to 205F, but two sourced guides agree light and dark roasts need different ends of that range, and one shows the rule's limit.
Why Does My Coffee Taste Burnt? The Real Causes, Ranked
Burnt coffee usually means over-roasted beans or water above 205F, not bad technique. Two sourced guides show how to tell burnt from bitter, and fix it.
Chemex Coffee to Water Ratio and Grind Size: The Complete Guide
Chemex ratio lands at 1:16 across two sourced guides, with a medium-coarse grind built around its thick filter. Here is the math and full brew steps.
Why Does My Coffee Taste Sour? The Real Causes, Ranked
Sour coffee is almost always under-extraction. Three sourced guides agree on the top fixes, but disagree on how much water temperature actually matters.
Instant Coffee Caffeine Content: How It Really Compares to Brewed
Instant coffee runs 30 to 150mg of caffeine per cup against brewed coffee's 80 to 100mg. Two sourced guides explain why the range is so wide.
Espresso Shot Too Fast or Too Slow? The Real Causes, Ranked
Espresso windows run from about 28 to 36 seconds depending on the guide. Two sourced guides agree dose and grind are the top causes of a fast or slow shot.
Does Coffee Expire? The Real Shelf Life Timeline for Beans and Ground
Coffee does not expire like milk, it goes stale. Three sourced guides put whole bean shelf life anywhere from 1 to 9 months. Here is what each one measures.
Starbucks Brewed Coffee Caffeine: Pike Place, Blonde, and Dark Roast by Size
Blonde Roast beats Dark Roast on caffeine at every Starbucks size, up to 475mg at Venti. Two sourced guides agree closely. Here is the full size-by-roast table.
Nespresso Caffeine Content: OriginalLine vs VertuoLine, Every Pod Ranked
Nespresso pods run from 1.7mg decaf to 200mg for Melozio Boost. Two sourced rankings mostly agree, except on Kazaar and Vertuo decaf. Full breakdown.
Drip Coffee Ratio: How Much Coffee Per Cup, Actually
Drip coffee ratio runs 1:15 to 1:18 across two sourced guides, and a machine's cup marking is rarely a true 8 ounces. Here is the real gram math.
Siphon Coffee Ratio and Grind Size: The Complete Guide
Siphon coffee ratio runs 16:1 by one sourced guide and 1:13 by another. Here is the reconciled range, the vacuum-brew method, and the grind it needs.
Why Is My Espresso Crema Thin or Missing? The Real Causes, Ranked
Thin or missing espresso crema traces to a short list of causes. Two independently sourced troubleshooting guides agree on stale beans, grind, and pressure.
Kalita Wave Coffee to Water Ratio and Grind Size: The Complete Guide
Kalita Wave ratio lands at 1:16 across two sourced guides, with a medium to medium-fine grind. Here is the flat-bed design, the math, and the brew steps.
Turkish Coffee Ratio and Grind Size: The Complete Guide
Turkish coffee ratio runs 1:8 to 1:12 depending on strength, with a grind finer than espresso. Here is the gram breakdown, the cezve method, and why it works.
Espresso Channeling: What It Is and How to Fix It
Channeling explains why an espresso shot can taste sour and bitter at once. Here is what causes it, how to spot it, and the puck prep fix that actually works.
French Press Coffee to Water Ratio: The Complete Guide by Strength and Batch Size
The real french press ratio range, 1:12 to 1:17, gram amounts for every press size, and James Hoffmann's full recipe timed out step by step.
How Much Caffeine Is Really in Death Wish Coffee? The 472mg vs 728mg Split, Reconciled
Death Wish Coffee gets quoted at both 472mg and 728mg of caffeine a cup. We pulled the actual lab numbers and found out whether they really disagree.
Coffee Consumption by Country: Why the Rankings Never Agree
Finland tops one coffee-by-country ranking and Luxembourg tops another, both citing the same trade data. We pulled the real sources to explain why.
Why Does My Coffee Taste Watery or Weak? The Real Causes, Ranked
Coffee tasting thin, watery, or weak despite a careful brew? We rank the real causes, dose, grind, temperature, and dilution, each with a fix.
The Coffee to Water Ratio Chart, and Why the Golden Ratio Is a Range
Gram amounts for every brew method and batch size, what the SCA's Golden Cup standard actually specifies, and why ratio alone cannot fix a bad cup.
Coffee Grind Size Chart by Brew Method: The Complete Micron Reference
Every brew method's grind size in microns, with a texture test you can feel, typical brew time, and why the numbers never transfer between grinders.
Can You Freeze Coffee Beans? What the Research Actually Shows
The 'never freeze coffee' rule turns out to be mostly wrong. A Scientific Reports grinding study and freshness research show what freezing really does.
AeroPress Coffee to Water Ratio and Grind Size: A Complete Guide
AeroPress ratios run from 1:4 concentrate to 1:18 full immersion. Here's the grind, water temperature and steep time for each mode, plus a fix it table.
How Much Caffeine Is Really in a Shot of Espresso?
The 63mg-per-shot figure everyone quotes traces to one USDA entry. Cafe-measured shots range far wider, and most cafes actually pour a double.
The Origin Atlas: How Where Coffee Grows Changes What You Taste
A working guide to coffee origins, Ethiopia, Kenya, Colombia, Brazil, Central America, Sumatra, plus the variety, altitude, and processing that shape each cup.
Coffee Roast Levels, Decoded: What Light, Medium and Dark Actually Mean
What happens during roasting, what light, medium and dark do to flavor and body, the caffeine myth debunked, and how roast should guide your brew method.
How Much Caffeine Is Really in Cold Brew? Reconciling the Wild Disagreement
Brand labels, a real lab study, and coffee blogs all quote wildly different cold brew caffeine numbers. We pulled the actual sources and reconciled them.
Why Does My Cold Brew Taste Woody, Bitter, or Sour? Five Real Causes
Cold brew coming out woody, harshly bitter, or oddly sour despite following a recipe? We walk through steep time, grind, ratio, beans, and vessel, with fixes.
Why Your French Press Coffee Is Muddy, and How to Fix It
The physics behind muddy, sludgy french press coffee, the exact fixes for grind, stirring and plunging, and James Hoffmann's no-plunge method explained.
Why Your Moka Pot Coffee Tastes Bitter (and How to Actually Fix It)
Moka pot coffee running bitter? Here's the physics behind it, five real causes ranked by impact, and a minute-by-minute heat curve to fix it tonight.
Why Your Pour-Over Stalls: Every Cause of Slow V60 Drainage, Fixed
Water pooling on your V60 and refusing to drop? We break down all five real causes of a stalled pour-over, from grind size to water chemistry, with fixes.
Trade Coffee vs Bean Box: What We Found Researching Both Subscriptions
A research-based comparison of Trade Coffee and Bean Box on pricing, matching, roasters, freshness and reviews, ahead of our hands-on long-term test.
Why Is My Coffee Bitter? The Real Causes, Ranked
The real, ranked causes of bitter coffee: grind size, water heat, brew time, dose, dirty gear, roast level and water chemistry, with a fix for each.