Chuckie: Eww! This coffee tastes like mud!Good coffee can be a connoisseur's delight, while bad coffee is Bad to the Last Drop. It might be very cheap, very poorly brewed, or very stale coffee, or it can be ersatz substitutes for coffee that just don't make the grade. To some extent, even good coffee is an acquired taste; many people load it up with cream and sugar when they first start drinking coffee for this reason. That's not this trope. This is when the stuff's so awful that if the drinker wasn't in the midst of a Must Have Caffeine moment, it would be thrown out. Sometimes subverted by coffee purists who argue that coffee should be cheap and poorly brewed, and call anyone invoking this trope on such beverages a snob. The trope name is an allusion to the Maxwell House slogan "Good to the Last Drop".note While this trope most commonly features coffee, any bad non-alcoholic drink can go here. Bad alcoholic drinks should see the Sister Trope, A Tankard of Moose Urine. Klatchian Coffee may overlap with this, or simply be another Sister Trope. Descriptions of such beverages may be some variant of "It Tastes Like Feet."
Tommy: It is mud.
Tommy: It is mud.
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- A 1979 Yuban coffee commercial has a wife lamenting that her coffee is so bad, her husband "never has a second cup of coffee at home."
- Parodied in Airplane! (with the same actress). "Jim never vomits at home..."
- A spot for Skechers shoes has comic book character Too Much Coffee Man freaking out because he has no filters for his coffee maker. He uses a shoe instead. The results are obvious; the taste of the coffee dubious.
Anime and Manga
- Fullmetal Alchemist has a running gag of the coffee in military headquarters being awful. And the one at the Northern HQ is not free.
- One Piece: In Ace's cover story, the Marines on their ship are complaining about the coffee being really bitter and all-around distasteful. (Adding milk, courtesy of one Marine officer's dairy farmer daughter, seems to improve the coffee ... which as noted above is Truth in Television.)
- In Zoids: Chaotic Century, Fiona's Trademark Favorite Food is salt. She puts it on or in everything she makes, including the coffee. Van normally likes drinking coffee, but can't drink anything she brews up because she uses salt instead of sugar.
- This is Ms Smith's reaction in Daily Life with Monster Girl when she tries drinking a cup of the cheap instant coffee served at a police command center. On the other hand, she thinks that Kimihito's coffee is the best brew ever, which confuses the heck out of him because it's the cheap instant stuff.
- Preacher: When a federal cop tells the state cop their coffee tastes like someone came in it, the state cop snarks back that they were so excited to finally get a 'real' cop that they just couldn't contain themselves.
- The very first lines spoken in Planetary, in a crappy diner in the middle of nowhere:
Elijah Snow: Coffee tastes like your dog took a leak in it.Waitress: Dawg's gotta go someplace.
- Another Warren Ellis-penned example, from his run in Excalibur: there were a few lines indicating that Moira MacTaggert's coffee was just awful (issue #88, in special, was a bit of a ragfest).
- In The Flight Of The Alicorn, Blueblood regularly burns his coffee while he's brewing it. Turns out he's never had a good cuppa in his entire life, so he thinks coffee is supposed to taste that bad. It's a revelation when Rarity brews him some good coffee.
- In A Slice Of Life, Princess Celestia's royal coffee-maker, Soggy Grounds, apparently has the special talent of making bad coffee.
- In Origin Story, Alex Harris is a "definitive coffee snob" who usually enjoys a special Indonesian coffee blend that costs $35 a pound. In Chapter 30, she is drinking a cup of coffee she bought at a New York City deli while staking out a badguy's job. She specifically remarks that she knows the coffee is Colombian because "it tastes like the oily mud the beans were grown in."
- In Godzilla (1998), the lead French investigator finds the New York coffee his assistant gives him to be awful. He still drinks it.
- The Three Stooges sketch "Of Cash and Hash" has the Stooges running a cafe with their usual screwing-up. One of their customers complains that the coffee tastes like paint, so Shemp drinks from the mug to see what's wrong. He grimaces, then says, "It is paint." He grabs another coffee mug. "That's the coffee." When Shemp drinks from it, and makes an even worse face. He goes back to the cup of paint: "This is better."
- Parodied in Austin Powers: The Spy Who Shagged Me, when Austin mistakes a stool sample for a cup of coffee.
Austin: Cor! This coffee smells like shit!
Basil: It is shit, Austin.
Austin: Oh well then it's not just me. [Drinks] It's a bit nutty.
- We don't know because it's never tasted, but in Dead Men Don't Wear Plaid Rigby makes Swede a cup of his "java," which consists of an entire bag of coffee grounds and two raw eggs (including shells). But Rigby & Swede are shot before they drink it.
- A running gag in Men in Black 3 has Agent K lamenting every morning that "This coffee tastes like dirt", to which Agent J (in the present) or Agent O (in the past) would reply, "It should, it was just ground this morning." (This joke clues O in on the fact that J actually knew K, after K was killed in the past by Boris the Animal.)
- In Elf, Buddy sees a sign on a Greasy Spoon diner declaring they have "the world's best cup of coffee", and he naively believes it. Later, on his first date with Jovi, Buddy tries to surprise her with coffee at this diner.
Buddy: Reach out in front of you and take a sip. Don't look.
[Jovie is blindfolded. She sips the coffee and makes a face.]
Jovie: It tastes like a crappy cup of coffee. [Removes the blindfold] It is a crappy cup of coffee.
Buddy: No, it's the world's best cup of coffee!
- In the Buster Keaton comedy The Navigator, a pampered heir tries to make coffee for the first time in his life; he uses ocean water. He adds a spoonful of sugar, tastes it- then dumps the entire container of sugar in his mug.
- Harper begins by showing the low-rent life of Paul Newman's title detective character as he wakes up. He sees he's out of coffee, so he uses yesterday's grounds in a filter pulled from the trash. He doesn't like the result.
- In The Polar Express the hobo offers the protagonist a "cup of joe", he gags on it, then the hobo takes his socks out of the coffee pot.
- In Love Finds Andy Hardy, older sister Marian, charged with fixing the meals when mother Emily is away tending to her own ill mother, makes atrocious coffee. Andy and the judge, seeking not to hurt her feelings, pronounce it excellent. This almost causes the new cook to quit when she comes to work, tries Marian's coffee, and pronounces it "mud."
- Monsters, Inc. subverts this trope by showing a scene in which Waternoose turns the spigot on a "coffee" machine, and a thick sludge slowly oozes out of the machine. This is expected of Monsteropolis coffee (much as smelling bad which normally calls for the use of odorants).
- In Pirates of the Caribbean: Dead Men Tell No Tales, the "tea" that Shansa offers her guests is pallid green and has a noticeably phlegmy consistency. Barbossa declines the drink.
- In Ancillary Justice, Radchaai have strong opinions about what does and does not qualify as "tea". Most of what's served in "uncivilized" space doesn't.
- In the In Death series set in the 2050-2060s, genuine coffee is an expensive luxury that only the rich can afford, most people making due with an artificially flavored substitute. Considering that the ersatz coffee on tap at Cop Central is notoriously bad even by this lowered standard, the top-quality real coffee that Eve's multi-billionaire husband Roarke supplies for her is treated as more precious than liquid gold.
- Robert A. Heinlein's Glory Road. The protagonist Oscar Gordon describes coffee as coming in five descending stages: Coffee, Java, Jamoke, Joe, and Carbon Remover. Carbon Remover is this trope.
- In the Discworld, we have the brew provided by Sham Harga, the one-cook biohazard who runs the renowned eatery, Harga's House of Ribs. Sam Vimes likes the coffee here, which is indescribably foul. (To the extent that when Harga actually cleaned the coffee urn, Vimes found the resulting coffee too weak, or, in his words, "love-in-a-canoe" coffee. It's fucking close to water.)
- There's a tea example in Exile's Valor — Alberich got some vile drinks as part of the Sunsguard, but even he considers the herbal teas at City Guard stations undrinkable.
- Horatio Hornblower suffers from the problem of very finite coffee supplies at sea. Usually, what he gets to drink is burnt bread and hot water.
- In Spirit Hunters Sura manages to make tea with the color and consistency of pine tar.
- In John Dies at the End, David compares the taste of John's coffee to a cup of battery acid that someone had pissed in and then cursed at for several hours.
Live Action Television
- The Beverly Hillbillies: Possibly the first instance of this trope on a television series, as it pertains to coffee. Elly May was a Lethal Chef and her coffee was highly viscous and nigh indigestible.
- Green Acres: Another early instance of this trope on a television series from producer Paul Henning. Eva Gabor's character, Lisa Douglas, was terrible at all things domestic and her coffee was no different. It would come out of the pot in a thick black sludge in many, many episodes much to her husband's dismay.
- A non-coffee example would be some of Mrs. Davis' concoctions on Our Miss Brooks. Mrs. Davis' coffee was usually fine (the time she made "Bulgarian Coffee" notwithstanding). However, being a Cordon Bleugh Chef, Mrs. Davis sometimes makes horrid liquid (albeit non-alcoholic) drinks that are truly Bad to the Last Drop.
- Barney Miller: The coffee is almost always horrible. Everyone thought it was the way Nick made it, until one time when Nick felt unappreciated and Wojo made some.
Nick: makes sour face All this time I thought it was just me.
- And during a water shortage, Wojo tries a coffee substitute: hot Dr. Pepper.
- Castle: Rick claimed that the coffee in the squad room tasted like a monkey had peed in battery acid. It was so bad he bought the squad room a cappuccino maker.
- One episode of Kojak had an elderly woman come to the station to give a statement. While there she asked for a cup of coffee, and upon tasting it gently tells the detective interviewing her that it's absolutely terrible.
- On Gilmore Girls this is a running joke; almost nobody but Luke can make coffee that's up to the girls' standards, and no one else can handle it at the strength they make it themselves.
- In the sci-fi series Starhunter, Percy comments on how bad the coffee in her cup is. She is seen chewing it.
- Stanley in Rizzoli & Isles makes really bad coffee. Jane accuses him of putting his sweat socks in the coffee maker.
- Blackadder the Third: Blackadder gives one of his circuitous insults to Mrs Miggins, owner of a coffee shoppe.
A cup of your best hot water with brown grit in it - unless, of course, by some miracle, your coffee shop has started selling coffee.
- An extended sequence in Blackadder Goes Forth has Baldrick explain just why his coffee is so awful; turns out the war means they ran out of real ingredients years ago, so in typical Baldrick style he's been using ersatz coffee (mud), ersatz milk (phlegm), and ersatz sugar (dandruff).
- M*A*S*H had several examples:
B.J.: This coffee is terrible, even by my standards!Hawkeye: And this is coming from a man who drinks lime koolaid with strips of bologna in it!.Klinger: Colonel, how would you like a delicious cup of coffee?Potter: I'd love it!Klinger: Me too, this stuff stinks..Potter: I told 'em strong, not lethal!Winchester: The undrinkable washing down the inedible.
- Narrowly averted in an episode of Night Court. The case of the night concerns the ashes of a man named Herb, whose two wives each want to keep the ashes. They are temporarily in Harry's custody. Meanwhile Harry's coffeemaker is on the fritz and the building manager Art fixes it. Later Harry finds the urn empty.
Art: Oh sorry, your honor, I had to use that herb tea to test the coffeemaker.Harry: Art, that wasn't herb tea, that was Herb.Cut to Dan frozen in place with a cup just about to touch his lips
- On Gimme a Break!, Chief Kiniski was on a stakeout and his partner drank from the thermos of coffee he brought (which was made by one of the daughters). He asked if it was supposed to be coffee. Kiniski looks at it and says "I think so. Turpentine doesn't have grounds in it."
- Neelix liked to experiment with coffee in Star Trek: Voyager. One first-season episode has him invent a glutinous "better-than-coffee substitute" that drives Janeway to redouble her search for energy supplies. During the "Year of Hell," he tries again with a concoction made of ration cubes.
Seven: It is offensive. Fortunately, taste is irrelevant.
- Crusade: In Visitors From Down The Street, Captain Gideon laments the poor quality of what passes for coffee available aboard starships (it was established on Crusade's predecessor Babylon 5 that real coffee is prohibitively expensive to get off-world). He goes on to voice suspicions that they only caffeinate the stuff to mess with him, thus setting the Conspiracy Theorist tone for the episode.
- Monty Python's Flying Circus: "Conquistador coffee brings new meaning to the word 'vomit'." (It's a sales pitch.)
- Angel had Angel Investigations' godawful coffee become something of a running gag, since none of them could afford the good stuff.
Angel: I think my oesophagus is melting.
- Ellery's coffee in Ellery Queen. In one episode Ellery's father (who, it should be pointed out is a homicide detective and therefore used to bad coffee) takes one sip and pours his cup down the sink. After a moment's thought, he follows this by pouring the entire pot down the sink.
- General Hospital: Brenda serves Sonny coffee, which he declares to be "the worst coffee I have ever had in my life."
- In the song "I Don't Want No More of Army Life", one of the verses goes:
The coffee in the army, they say it's mighty fine.It's good for cuts and bruises but tastes like turpentine!
- Kate Bush's "Coffee Homeground": "Well, you won't get me with your Belladonna, in the coffee"
- The bus drivers in Crankshaft endure Lena's notoriously bad coffee (which is still better than her unspeakable brownies).
Irma: Oh, that's our coffee. Our tea tastes like transmission fluid.
- In Irma's diner where Jon complain about the drink he was sold; he couldn't tell whether it was coffee or tea because it tasted like turpentine.
Irma: Interesting question... No one's ever asked for a second cup.
- Another one in Irma's diner has Jon ask if the refills are free before tasting the coffee.
- Happens on Cabin Pressure:
Arthur: Here you are, skipper. Nice, hot cup of coffee.
Martin: [takes a sip] Ugh, it's cold!
Arthur: Nice cup of coffee.
Martin: It's horrible!
Arthur: Cup of coffee.
Martin: I'm not even sure it is coffee.
- The Deadlands setting has a spell called "Coffin Varnish" note , which conjures coffee of this kind that doubles as a Hideous Hangover Cure.
- In the GURPS setting Transhuman Space, "Martian coffee" is slang for "really bad coffee" (because of the poor water quality in the Martian colonies). The colonists tend to spice it very heavily to mitigate the taste.
- In Phoenix Wright: Ace Attorney, the coffee that Lethal Chef Armstrong serves is, in coffee addict Godot's words: 'worth a sip for the experience alone.' Just a single sip...
- In Max Payne, Max makes a stop during his one man war on to mob at an all-night diner where he drinks several cups of coffee that in his own words "tasted like engine oil."
- One of Jesse McCree's lines in Overwatch at the start of a match in the Route 66 map while the team is in a spawn point that is a diner is "Yeah, I wouldn't drink the coffee. Always tasted like boiled dirt."
- One of the "MessageMates" (small programs which display a short humorous animation and end with a message ... and try to infect your computer with spyware), titled "Bad Coffee", is about the characters complaining that the coffee they're drinking tastes like "monkey piss" and then discovering an actual monkey inside the coffee vending machine.
- The Order of the Stick:
- In the graphic novel "Start of Darkness", Xykon is something of a bad coffee fan, as drinking a really horrible cup of coffee reminds him of all the good coffee he can compare it to. He's infuriated when he tries his first coffee after becoming undead, and can't taste it at all, good or bad.
- In one strip, Vaarsuvius pranks Belkar by leaving out "Explosive Runes" brand coffee. V filtered the coffee through Roy's sweaty socks, to ensure Belkar would be disgusted enough to grab and read the coffee can.
- In Something*Positive, Aubrey complains that the coffee in a donut shop "tastes just like a diaper smells." Flinging the cup to the ground, she claims that she could "menstruate a better cup of coffee." When the cashier tells her to leave or he'll call the police, she counters with, "When it comes to bad coffee and donuts, whose side do you think a cop will be on?"
- In this page from Blood Stain, Elliot can barely drink Serge's coffee, but since she's a new employee she doesn't want to rock the boat, so she says that it's great.
- In Freefall, after Florence the Bowman's Wolf expresses concern about coffee being possibly toxic to her, Dvorak synthesizes a canine-safe substitute. It smells like a frightened rabbit, which is distinctly appealing to her wolf instincts, but the taste drove her to scald the taste off her tongue with regular coffee.
- DuckTales (1987): In ''Aqua Ducks", Gyro Gearloose invented a new type of health drink that, in Launchpad's words, tasted like "old tires." It turns out vulcanized rubber was a major ingredient.
- In one "Mr. Know-It-All" segment of Rocky and Bullwinkle, Bullwinkle goes to a coffee shop and waiter Boris suggests "Cafe Minuto". Bullwinkle drinks it and cringes, then Boris says it "should be bad to last drop."
- On Ricochet Rabbit and Droop-a-Long Coyote, Deputy Droopalong's coffee is so thick, it has to be cut with scissors when it's poured.
Ricochet: Is that coffee I smell, or is somebody burning a boot?
- In the Steven Universe episode "Drop Beat Dad", Sour Cream's biological father (and Greg's old manager) Marty tries to shill Guacola, a guacamole-flavored soda, at Sour Cream's rave. The stuff resembles green slime and everyone in the audience hates it (with the exception of Sour Cream's half-brother Onion, for some reason).
Ronaldo: Guacola. It’s a soda that pays people to say they like it, so you know it’s good.
- Ronaldo Fryman later agrees to shill for Guacola on his blog to make some extra cash, even though he can barely hide his disgust for the "drink" and the nicest things he can say about it are that "it is technically edible (even if you do have to chew it sometimes)" and that it can also be used as industrial mortar (or to "clog a drain that runs too smoothly").
- In the Rated "A" for Awesome episode "Sleep Smart", Cashola Company releases a nasty potato flavor soda (that only Lars seems to like) and has to resort to having subliminal messages played on TV to hypnotize people into buying it.
- Ironically for the company that popularized specialty coffee and espresso in the U.S., coffee snobs see Starbucks coffee as this, due to the chain's use of dark-roasted beans. Serious coffee fans prefer lighter roasts, typically medium roast ("full city") or lighter. Darker roasts, sold as "French roast" or "Italian roast", obscure the regional characteristics of the bean. You're really only tasting the roast at this point. Roasters typically use poor-quality beans that would otherwise be thrown out for their dark roasts. Many coffee fans also dislike the overly smokey flavor of dark-roasted beans, which is why many of them nickname Starbucks "Charbucks."
- McDonald's coffee also has this reputation, especially since they used to burn it by serving at 180 degrees F instead of 140-160 like most restaurants. Before an old lady got third-degree burns and sued. (What, you thought that was a Frivolous Lawsuit? Boy, do we have a story to tell you...)
- Coffee made from percolators is said to fit this trope, especially if the coffee is allowed to brew for too long.
- Instant Coffee (brewed and then freeze-dried and packed) has a very strong reputation for this. Then again, if you find yourself needing instant coffee (i.e.: you need the coffee, but lack the time or money for a properly brewed cup), then Beggars Cant Be Choosers. The trend pretty much started in World War II where time and space constraints meant the troops had to settle for instant "Cup o' Joe". In Europe and Asia, instant brands sold tend to be of higher quality than the kind Americans are used to. The freeze-dried brands are a closer approximation to brewed coffee than the cheap spray-dried brands are. On the other hand, instant tends to dominate in markets like the U.K. and Japan, which have historically been tea cultures and simply may not know any better, and which have tea-brewing infrastructure (read: super-fast boiling kettles) that make making instant coffee very easy.
- By the same token, instant tea also has this reputation, only more so. It doesn't have much of a market, since it's not much cheaper than a lot of real tea (especially the crap they put in tea bags), and making normal tea only takes a few more minutes than instant (since you still have to boil the water to make instant, it's just a matter of waiting 3-5 minutes for your brew vs. drinking the instant, erm, instantly). On the other hand, instant green tea is getting more popular in Japan, where tea, like everything else there, is Serious Business. This is due to the desire for greater convenience, Japan's aging population, and the ability to make cold and hot tea from the same powder. It also helps that a lot of the instant green teas include a bit of matcha (a good powdered green tea with exacting standards because it's the standard bearer for tea ceremonies) for better flavor.
- Drip coffee, even if it's pretty all right to begin with, becomes this very quickly if you let the pot sit on the coffeemaker's hot plate. Most of the cheap automatic drip makers also don't get the water hot enough to get a good extraction either. Good coffee should be consumed immediately after brewing and never reheated. Otherwise, coffee should be kept in a thermal carafe or Thermos. This is why coffee buffs prefer manual pour-over drip coffee makers, though there are still ways to screw up coffee with those as well, as mentioned below.
- There are two main strains of the coffee plant: arabica and robusta. Arabica is far more flavorful and slightly lower in caffeine content, whereas robusta is nearly flavorless and relatively high in caffeine. The latter is also, true to its name, more robust and able to be grown more easily and in more environments than arabica, which prefers high elevations and shade. Thus, robusta coffee is much cheaper to grow, and is the main ingredient in very cheap coffee blends and instant coffee, mixed with a small amount of arabica coffee for flavor (on the exact opposite end, robusta is also used by a few European espresso makers to give their coffees stronger crema, the topping on an espresso). 100% arabica coffee— the kind you get at any self-respecting coffee house, and these days even on most grocery store shelves and fast food places— is much tastier than a robusta blend for this reason. And now you know.
- Another factor that contributes to this trope is the freshness of the roast. Green (unroasted) coffee beans can be stored for years with no ill effect, but once they're roasted (giving them that familiar brown color), you've got about two weeks to brew them before they're considered stale. You see that "Roasted On" date clearly marked on that bag of coffee at the grocery store? That's right, you don't, because they don't want you knowing how long it's been sitting on the shelf or else no one would ever buy a bag more than two weeks old. If you want truly fresh coffee, you've got to find a reputable local roaster or else do your own roasting at home.
- Even worse is coffee that's pre-ground. You know that wonderful smell that wafts out of a bag of ground coffee? That's the taste of your coffee escaping into the air instead of going into your cup. For truly good coffee that averts this trope, you need to buy whole-bean coffee and grind it immediately before brewing.
- Similar to how many fans of microbrews feel that major brands like Budweiser are A Tankard of Moose Urine, serious coffee afficionados have the same disdain toward major coffee brands like Starbucks, Folgers and Maxwell House.
- Skilled baristas can tell just by looking at the crema that a badly-made espresso shot is this.
- Even though the French press is one of the brewing methods of choice for gourmet coffee, if you let the coffee sit in the press too long, it will become overly bitter. Pour any unused coffee into a thermal carafe or a thermos. Also, the French press lets the sediment through that a paper filter will catch, which some people don't like. The press also calls for a coarse grind, or else the grounds can slip through the mesh filter.
- French soldiers during the Franco-Prussian War, when the mobile cantina wasn't here, made their coffee by boiling the crushed beans in a bucket or a tub, then filtering it through their socks. The taste was so awful that a bad tasting coffee is still called jus de chaussettenote in France over a century later.
- The Finnish Army brand tea is so horrible it is sometimes labeled as 3V Tea: Vangeille, varusmiehille ja veturinlämmitykseen ("For convicts, conscripts and compound engines").
- Coffee is normally acidic in nature, but if it tastes very bitter or astringent, something in the coffee is off balance.note Usually, it means it's gotten too strong or lost its aroma. That's why creamers, sugars, and lemon juices are common at coffee bars; all of them help to mask bitter coffee, though they can only go so far, especially if the coffee's thickened, cooled, and otherwise gone well past its prime.
- The pour-over is another go-to for coffee aficionados, but there are several things that can cause a bad cup of coffee. Water that's too hot will over-extract the coffee, making it bitter, as will using a grind that's too fine. A grind that's too coarse will give you a cup of vaguely coffee-flavored hot water.
- The coffee in workplace breakrooms, or in the cafeterias of institutions such as colleges and hospitals, is said to be appalling.
- This is especially true for coffee that's been provided for an all-day or multi-day event, like a hackathon. The coffee might taste okay in the morning soon after its been brewed, but as time goes on, you might as well dump the rest in the sink and do everyone else a favor.
- And none of these hold a candle to the awful that is truck stop or gas station coffee. Name a mistake made in the brewing process; cheap robusta beans of dubious quality that have spent who knows how long in a storage closet, too hot of water, unconditioned hard water sources, too fine or coarse a grind, machines that are never cleaned well, the pot standing too long on the hot plate, etc. Chances are several of these are in play. At least it's cheap, and if you have to drink it, you're definitely in need of it. On a related note, truck drivers tend to have really bad taste in coffee, due mostly to this being their primary source of same.
- Quote ascribed to Abraham Lincoln:
If this is coffee, please bring me some tea; if this is tea, please bring me some coffee.
- Serious coffee fans prefer burr grinders over blade grinders because the latter often leaves inconsistent particle sizes, leading to the problems with over-and-under-extraction described above. The whirling blade can even burn the ground beans. Burr grinders grind the beans evenly, which is essential for getting a good extraction.
- Steeping green tea in water that's too hot will make it taste harsh and astringent.
- Somehow a tradition arose in the US Navy that neither coffee makers nor drinking mugs should ever be cleaned. This supposedly made the coffee more palatable (or rather, less unpalatable) then it would otherwise be. Possibly this was from a time when poor water quality and lowest-bidder coffee meant that the coffee would be bad no matter what you did. In any event, the result was a bad but consistent flavor that sailors grew used to.