James Hoffmann Answers Coffee Questions From Twitter Tech Support WIRED

I'm James Hoffman, an author and coffee expert, and I'm here to answer your questions from Twitter. This is Coffee Support. First up, Black Horse Cough asks, caffeine myths, dark versus light. Does the type of roast affect how much caffeine is in coffee? This is a really good question. Let me get some dark and light roasts for you. Now, a lot of interesting stuff happens in the roasting process. With a lighter roasted coffee, technically speaking, more of the caffeine that was in the raw coffee is still in the coffee. To get a darker roast, the coffee spends more time in the roasting drum, and it gets up to the kind of temperatures where caffeine sublimates. It goes from a solid to a gas, which is kind of interesting. But this is the important thing. This coffee is denser, and if I took 10 grams of this coffee and 10 grams of this coffee, there'd be more beans to make up the 10 grams if I was using the darker roast. So while there might be less caffeine per bean, I'd be using more beans. And so ultimately, the amount of caffeine will vary a lot more by the type of coffee being roasted, whether it's Arabica or Robusta, whether it's high-grown or low-grown. The roast itself is not something you really need to worry about. Robin Jerry Lee asks, is there any good instant coffee? There is. There is good instant coffee now. For a long time, there was not instant coffee. The point of instant coffee was cheap, cheap, cheap coffee, and that applied to the raw coffee going into it. These days, there are good specialty coffees being turned into instant coffees. But really, the difference is down to the raw materials. By putting good raw coffee, well-roasted, into the whole process, you get a surprisingly good result out. Alison D. Rush asks, how do coffee beans grow decaffeinated? Good question. Coffee does not grow decaffeinated. Coffee trees actually produce caffeine as a form of insect repellent. The higher you grow coffee, the less caffeine it needs to produce because the less insects there are. Now, when we decaffeinate coffee, that's actually a process that's done after harvest, but before the coffee is roasted. And there's a bunch of different ways to decaffeinate coffee, some of which have very nice-sounding names like Swiss water process. Others have terrifying names like ethyl acetate. But ultimately, all decaf processes are very safe and generally have to remove 99.5% of the caffeine from coffee to be certified as decaf. However, they are now starting to experiment with new varieties of coffee that are naturally very low in caffeine. So keep an eye out for those. Those don't need decaffeination, and they'll have way, way lower levels of caffeine than normal coffee. Let's see what's next. The Pour Over blog asks, what's the ideal temperature for coffee? That's a good question. It has a bunch of different answers because I don't know at what point you're talking. If you're talking about brewing coffee, then generally speaking, close to boiling point is the right temperature for water for brewing coffee. If you're talking about drinking coffee, that's a very different answer. Now, the interesting thing is very hot coffee doesn't taste as good as coffee getting closer to kind of body temperature. When coffee goes from hot to kind of enjoyably warm, it starts to taste much, much, much better. And so letting your coffee cool down a little bit before you drink it gives you a more complex, more interesting experience, ultimately because you as a human, you're just not very good at tasting stuff that's a long way away from body temperature. JNKVMK asks, does anyone know how to make espresso without machine, LMAO? Okay, I have to do it. I have to just cover this quickly. The drink is technically espresso, not expresso. A large faction of the internet will get very angry with you for using the wrong one. I'm not one of those. And actually in France, it is the correct term. It is espresso in France. Anyway, espresso is interesting. You can't really make it without a machine because of what defines it as espresso. Now, espresso machines are really expensive because they do a bunch of stuff in terms of temperature and pressure and all that kind of stuff. But if you just wanted to make really good, but really, really strong coffee, there are a couple of bits of coffee kit though that can make really delicious, strong coffee. Let me show you what I mean. I love both of these and they're very different, but they can both make really strong coffee. This is an Aeropress. It's super cheap, indestructible, $20, $25, worth having, great to travel with. And this is the time-honored classic. This is a mocha pot or a stovetop brewer. Both of these can make really strong coffee. And by sort of strong coffee, I'd be anything from almost espresso strength of like one part coffee to three parts water up to a kind of traditional mocha pot brew of one part coffee to 10 parts water. Or if you have a way to foam milk at home, you can make a delicious kind of homemade cappuccino. But Kaya next door asks, what about coffee makes me have to dookie? Like, I don't understand that part. It is weird. It's kind of weird that when you drink coffee, that can happen really quickly. Like, like really quickly. There's no way that it worked its way through your digestive tract all the way down and then made the magic happen. So science doesn't truly understand what's going on. The sort of main theory is that it actually triggers a hormone response. So when you drink coffee, your body releases a hormone and that's what triggers the need to run to the bathroom with great speed. At Sleepy Lyra asks, why do people put milk and sugar in their tea and coffee, especially sugar? Like calm down and learn to love the bitter and not alter and change what the drink is supposed to be. It's a good point. There's a lot of reasons to put milk in coffee and mostly they are the coffee tastes bad. Now milk is gonna add a little bit of sweetness to that drink. That's definitely gonna help but milk does another very cool thing. It acts as a bitter blocker. So when you've got harsh, bitter coffee, sugar doesn't actually decrease bitterness. You can add a little bit of salt and actually if your coffee is really bitter, a tiny pinch of salt is a wonderful thing but milk comes in and actually masks some of the bitterness and that's partly the sort of proteins in the milk and also the fat in the milk too, which will give it a kind of nicer texture and mouthfeel. As for tea, yeah, I don't know. I don't, I don't really get milk and sugar in tea either. So I'm with you. At snack impact pod asks the timeless question, what's the difference between hashtag cold brew and hashtag iced coffee? This is a big one and this is where people really divide into camps, especially on the internet. So cold brew is cold coffee made with cold or room temperature water. That means you have to steep it for a really long time because cold water isn't very good at pulling the flavors out of the grounds. Iced coffee is hot coffee made strong and then rapidly chilled by brewing directly onto iced. That way you tend to get all of the complexity of the sort of the coffee because it was brewed with hot water but you get a nice chilled delicious beverage at the end of it. Cold brew is generally less kind of complex and interesting and has a kind of cold brew taste that some people really like and other people, especially those who work in the coffee industry tend to identify as a slightly oxidized and stale taste in coffee and they get very angry about cold brew. However, a lot of people think cold brew is better for their stomachs. They like the taste. If you enjoy cold brew, enjoy cold brew but if you really love cold coffee I would recommend at least trying iced coffee. TS Organics asks what climate is best for growing coffee? The best climate for coffee has a couple of really important things. It has warm sunny days and then cool evenings. You tend to find that at higher altitudes. The lower altitudes will get lots of sun but they won't have the cool evenings. The reason you want this kind of diurnal swing as they call it between days and nights is that you want to feed the fruit or the tree with loads of sunshine but then you want cool nights to slow the maturation process that gives you a denser coffee seed and more complex, ultimately, cup of coffee at the end of it. So the best, most valued, most kind of delicious coffees tend to come from countries that have tons of very high altitude. Colombia or Panama or Costa Rica, Ethiopia, Kenya, countries like that. Then you also have these weird little sort of exceptions to the rule which are called island coffee. So places like Hawaii where you have less altitude but because it's an island and you get the cool sea breeze coming in the evenings you get this kind of matching climate where you have warm sunny days and cool nights. On to the next one. Lab Splaining asks, okay, I have an important question for coffee drinkers. How much coffee do you put in your coffee? What's your grounds to water ratio? Because apparently, compared to my friends, I drink pure rocket fuel. So now I'm curious. Firstly, when it comes to coffee to water ratios there's no correct answer. It's basically preference but there are some guidelines that work for most people. I would recommend people brew 60 grams of coffee per liter of water. Or if you turn it back into a ratio, one part coffee to 16 parts water, but it could be 15 to 17. That's the kind of rough area there. To help you with this, I would strongly recommend a kitchen scale like this one. The reason I like these is that I'm usually making coffee before I've had coffee. And I don't really wanna think about the coffee making process but if I know just how much coffee to put in, how much water to put in, I'll get it right every single time and I'll be very kind to myself. So these cheap, essential, good for cooking, get a set of scales. Philip Brown asks, does grinding your own coffee beans make much of a difference to the taste? It makes a huge difference to the taste. If there was one thing that I could sort of make everyone in the world do, it would be grind their own coffee beans fresh. It is delightful. They smell amazing and your drink tastes so much better. I feel like almost everyone owns a pepper grinder. You're willing to do like a little bit of work for a tiny component of one dish and coffee, that's the only ingredient and you get all the benefits. It tastes better, more complex, more delicious, more enjoyable and you get the smell as an extra bonus. Grinding your own coffee is a wonderful thing. Satnam asks, there's no real difference between a latte, flat white and cappuccino, is there? We're just humoring them. No, no, there's a difference. They all have different histories and they have some key differences in terms of strength as well as texture. A latte is probably the weakest of the drinks there. It's a milky coffee. It might have a thin layer of foam. Conversely, a cappuccino should be a much stronger drink. It should have a nice thick moussey layer of foam on top of it's good. Now the flat white, the Antipodean invention, lives between those two things. It's the texture of a latte but the strength of a cappuccino. In terms of histories, the oldest drink by far is the cappuccino and it's not Italian, it's Austrian. Back then it was called a cappuccino and it was just black coffee and milk mixed to the color of the Capuchin monks robes which is very specific. Cafe latte really is kind of an American invention. That sort of happened when coffee spread outside of Italy. Latte macchiato exists in Italy maybe but the flat white, that's Antipodean and they argue, the Kiwis and the Aussies about who invented it. We don't know but that's their invention probably in the 1990s. Bob Hyatt asks, okay coffee snobs, help me in my ignorance. The difference between drip coffee and pour over coffee is, well, not that much. In terms of the finished drink, they're the same thing. It's kind of down to how they're made. If you see pour over in a cafe, that's probably an individually made cup of coffee where you have something like a cone, coffee inside and someone's pouring water over the top of it. Drip is kind of the category of filter coffee and it can come from a batch brew, it can come from a pour over, a Mr. Coffee at home. That's all making drip coffee. Pour over is just like the fancy subset within drip coffee. Van Vicious asks, I was thinking that maybe siphon for coffee brewing works the same like a bong, eh? Hashtag bong, hashtag coffee, hashtag weed. Can't speak to bong usage but I will show you how a siphon works because it is a lot of fun. Gonna need a few different bits for this though. This is the fanciest way to heat a siphon. This is an halogen light heater. And then this is a siphon and it works in a lovely way. It's a nice science demonstration. We're gonna start with putting some hot water in the base of this thing. Start to get it hot, yeah. And then we're gonna put this piece in here because these little balls here act as a nucleation point. If you boil water in a smooth vessel, you can actually superheat the water and that's bad. Don't do that. So once the water starts to boil, we'll put this top piece on and that will create a seal in this bottom chamber. And as the water boils, it creates steam and that steam's gonna expand and push the water through the tube up into this top section here where we can add coffee and we can brew. So this is clever because even though this water is boiling hot, this water isn't boiling hot and it's kind of a nice temperature for brewing coffee. So you can reduce the heat a little bit here and then we're gonna add our coffee. Give it a little mix. You want all those grounds to be nice and wet. Now this is one of the most enjoyable brews to sort of smell as you go at the start. Smells kind of harsh and piney and resinous. And after about a minute, it will start to smell really sweet and you kind of know the brew's pretty much done. And at the end of the brew, this is the fun bit. When you turn off the heat here, that steam is gonna start to cool and it'll start to contract and it will create a kind of negative pressure that will start to suck the grounds and the water through the filter. We'll end up with our delicious brewed coffee down at the bottom here. And you're ready to pour and enjoy your siphon brewed coffee. Guaranteed to impress your friends, though not something you wanna do every morning. Perfect Daily G asks, full immersion or filter coffee? What's your favorite? Now this refers to the kind of two big schools of coffee brewing that are out there. Let me show you examples of each one. You've got full immersion, and that's like a French press where all of the coffee and all of the water hang out together for a while and then you separate and strain them. Versus filter coffee, that's usually more of a percolation. And there, you're pouring water onto a bed of coffee and the water is sort of passing through and percolating through it. And these can be a little bit more difficult to get right. These are very easy ways to make a coffee. And so I love a French press for being really, really simple, effortless, and a wonderful way to brew almost any coffee really well. So from an ease perspective, definitely love full immersion brewing. A question from at Fislawerb4, can you eat raw coffee beans? I mean, you can, you shouldn't. Don't chew them, they're really hard. Raw coffee is much, much harder. It's a plant seed and it's quite big. It's about the size of a peanut. So don't chew it, you might crack a tooth. But if you ingest it, yeah, it's just gonna pass right through you. That's what seeds are designed to do. So, you know, some people have chosen to drink the results. Don't do that, don't do that. Coffee fruit, however, if you get the chance to eat fresh coffee fruit from a tree, is delicious. They look like grapes, but they're mostly seed and they're kind of tangy, watermelon-y, delicious little fruits. Definitely eat those. David Alvarezzi asks, who invented coffee? I wanna kiss you, but after this poop, I just had coffee. This is a great question because we don't know. It's really interesting. We kind of have no idea of this really important moment in humanity's history. We know that people were drinking coffee in the 15th century in and around Yemen and the Arabian Peninsula. And we know that before that, in Ethiopia where the sort of coffee tree first flourished, people were eating coffee fruit from the tree. But this moment where someone was like, I'm gonna take the seeds from this fruit, squeeze them out, I'm gonna dry them. Then I'm gonna roast them. Then I'm gonna smash them to little pieces. Then I'm gonna put it in hot water and then I'm gonna drink that hot water. That moment of genius, we have no idea when and where that happened. Tommy Udo asks, is it possible or desirable to roast your own coffee beans at home in a domestic gas oven? Well, it's possible. I would not say it's desirable. I have a little bit of raw coffee here. That's raw coffee. It's pale, it's green. It's a very dense plant seed. Now the roasting process is where a bunch of magic happens. It's where it goes from tasting like a plant to tasting like a delicious cup of coffee. You can do it in an oven, but that coffee won't roast evenly. The bits in contact with your baking sheet will sort of roast a lot faster because the convection of the air and the conduction of the pan itself. A commercial roaster will constantly churn and toss and move the coffee around to make sure that it's roasting evenly. And uneven roasts tend to taste harsh, bitter, charcoaly, and a little bit burnt, but it can be done. And people do do it, so feel free to experiment. But I warn you, if you think coffee is a weird hobby, coffee roasting is far more of a terrifying rabbit hole. At Darren Shaw asks, should you freeze your coffee beans? And I would say, yes, yes, you should freeze your coffee beans if you're going to store them for a long time. If you've got way too much coffee in the house and you're not gonna get through it in the next few weeks, package it up, sort of airtight, that's kind of important, and then freeze it. It'll keep a really long time in the freezer. You can grind from frozen, but I wouldn't recommend kind of opening a bag and pulling out a handful of beans at a time. If you're gonna sort of brew a bag, pull it out. You can defrost it, it's fine. You can use it from frozen that first time. It doesn't really matter. But freezing the coffee beans is definitely a very good thing. Don't bother putting them in the fridge. Don't put ground coffee in the fridge. That doesn't really slow down the staling process and you can kind of cross-contaminate. You can make your food smell of coffee and your coffee smell like the food in your fridge. So freezer is good, cupboard is okay, fridge is bad. Innit Ink asks, why are they putting nitro in my coffee? What's happening? Well, they're doing it for two reasons. Firstly, it looks really cool. You get that kind of Guinness effect, a kind of nice foamy head. It looks beautiful. And then they're doing it for the same reason that kind of beer does it, in that it adds some really nice texture to the finished drink. You end up drinking this kind of black coffee that's somehow almost creamy like a cappuccino. That's mostly it. I think beer pioneered this stuff and coffee was like, we can use the same equipment and do the same thing and the results are pretty fun. So a very common question from Food Express Ink, is coffee actually good for you? And I think we can say with a decent degree of certainty, yes, yes, coffee is good for you. Now, there's a load of different studies done on coffee and we've got good data saying coffee is good for the microbiome. It contains a surprising amount of fiber. Coffee is good for your heart. We see reductions in heart disease as well as arrhythmias. There's lots of supporting evidence from loads of different studies around the world that says coffee drinkers live longer. But, and this is a really important but, that doesn't mean you should just drink as much coffee as you want. The moment that coffee starts to interrupt or disrupt your sleep, that's too much coffee and it's now bad for you again. So that's the sort of line in the sand. The minute you start to struggle to go to sleep or have decreased sleep quality, that's when you need to dial back your caffeine consumption. Coffee Fiend MA asks, what is the difference between hashtag coffee and hashtag espresso? Espresso is a very small, very strong cup of coffee brewed from incredibly finely ground coffee under high pressure at high temperatures. So it's like an intense extract of coffee. Typically it's brewed at nine bars of pressure, which may not mean much to anyone, about 130 PSI. And you do that because when you grind the coffee really, really, really fine, you need to sort of push the water to be able to get it through the coffee. Now I've got some samples of grounds here. Espresso ground coffee, it's not quite flour fine, but if you sort of pinch it, it will retain its shape. It's really pretty fine. Whereas for drip, it's more like a coarser sugar kind of thing. You can feel much bigger pieces between your fingers. And with espresso, you're gonna use a lot less water because you need less water because there's a lot more flavor exposed in the grounds by grinding them so finely. So that's the definition of espresso. A small amount of liquid, tons of coffee flavor, brewed under pressure, which also gives it a lovely red-brown foam on top called crema, and it must be done under those high pressures. At katiebizguz33 asks, I think I burnt my coffee. Is that even a thing? And the answer would be maybe, it depends how you think you burnt your coffee. If you think you burnt your coffee by putting boiling water on it and you've got a kind of burnt, harsh taste, no, you didn't burn it. That flavor is just in the coffee already and the very hot water extracted the flavor out of it. However, if you think you burnt it by putting it on a hot plate for half an hour, an hour, then yes, you kind of did. You kind of cooked it, you generated a bunch of new tastes in the liquid and yeah, it's gonna taste harsh, bitter, and unpleasant. And then yes, you did burn your coffee. Marcia Herald asks, I have a question since I'm not a parent. At what age do you start letting kids drink coffee? There's not like a rule here. There's actually no real guidance. I read at one point schools in Brazil were giving coffee to children to help them concentrate in math lessons. Kids as young as nine. So, you know, from a biology perspective, nothing particularly bad is gonna happen. But if you have a traumatic bedtime most evenings, I suspect giving your children caffeine is not a very good idea. Young Salami Boy asks, mistakenly got sugar in my coffee. Absolutely disgusting. Who does this? A lot of people put sugar in coffee. Now, sugar doesn't reduce bitterness, but a lot of bad coffee can also be quite sour. And at that point, sugar is kind of making things a little bit better the way that sugar makes lemon into lemonade. So sugar does balance out acidity, make the whole thing more enjoyable, and ultimately a little sugar helps the medicine go down. But if your coffee is good to start with, if it's well brewed, if it's, you know, fresh, it should have a nice natural sweetness. It shouldn't be dominantly acidic or bitter. Then sugar kind of makes it all kind of out of sorts, out of balance, and it does indeed ruin it. So good coffee needs no sugar, but if you like a little sugar in your coffee because you like sweet things, then go right ahead. At Molly Wood asks, why does coffee taste gross when you microwave it? And it's not just microwaves. If you reheat coffee from, say, cold back to kind of hot again, what you're doing is feeding in a bunch of energy and getting a bunch of chemistry going again. And that chemistry generates new flavor compounds. Those are often quite harsh, astringent, and bitter. And so you just want to avoid reheating coffee. Sadly, if it's gone cold, there's not much you can do to make it taste good again. VidCon asks, how many cups of coffee a day is too much? And this is a difficult one to answer. I'll give you what we know. There is a guideline for most places saying for caffeine consumption, 200 to 300 milligrams a day is your recommended dose. That's great, except you have no idea how much caffeine is in the particular cup of coffee that you're drinking. And two competing businesses will sell, let's say two cappuccinos that will have wildly different amounts of caffeine in them. In addition to this, there is a genetic component. Some people are fast caffeine metabolizers. Some people are slow caffeine metabolizers. So generally speaking, for most types of coffee out there, three or four cups a day is probably fine, unless it's messing with your sleep. Some people can drink more and feel absolutely fine. They can have a double espresso after dinner and go straight to sleep. They are the fortunate few. But for most people, three, four cups a day, I would say is a good sort of level to aim at. At Aimer, Anna asks, what makes Turkish coffee has this strong spice taste to it? Well, the strong bit is how you grind coffee for Turkish brewing. You grind it almost as fine as flour. So it's going to be very strong because you're going to get all the flavor out of those grounds. Secondly, it is not unusual to add spices to the pot as you're brewing. Cardamom is very common and that will obviously give it a delicious sort of spicy twist. At Salt Grumpy asks, Irish whiskey in my coffee. Good for a cough suppressor, right? I can't speak to that aspect of it. If that works for you, that's great. It is delicious though. I think whiskey and coffee are totally good friends and not just Irish whiskey, all whiskeys and coffee, I think can play very nicely. Recommended if you haven't tried it. And finally, Aksha asks, what happened to Dalgona coffee? You're moved on so quick. Well, they let us go outside again. I think that was a key part of this. Dalgona blew up during the pandemic when we were stuck inside and it involved things that most people had at home. It was instant coffee, sugar and a little bit of water, a whisk and spare time. We all had those things and I think Dalgona was the perfect coffee treat for the time. However, as fun as it is, it's not particularly delicious and I think once we could start going to cafes again and enjoying the great coffee scene, we wanted to do that. All right, those are the questions. That was coffee support. I hope you learned something. I hope you're in the mood to go and brew a cup of coffee and enjoy it. Thanks so much for watching. I hope you have a great day.