Many believe the answer is espresso. After all, espresso is concentrated coffee, brewed by the pressure of hot water flowing through finely-ground coffee beans. With espresso being a small, concentrated amount of coffee, it would make sense that espresso has the most caffeine. But, drip brew coffee has hot water continuously passing through coffee grounds, potentially extracting more and more of the caffeine out of the bean, so drip brew has to have more caffeine than espresso. Then again, with a french press, coffee grounds are soaked with hot water for a full infusion, steeping with full on contact for 4 minutes, so french press brewing has to extract more caffeine than both espresso and drip brew… right?

Back in ’79, Bunker and McWilliams published a paper after studying the caffeine content of common beverages. Here are their coffee-based findings (caffeine content noted in mg):
* espresso: 1 cup (1.5–2 oz, 45–60 ml) = 100 mg
* brewed: 1 cup (7 oz, 207 ml) = 80–135 mg (107.5 mg average)
* drip: 1 cup (7 oz, 207 ml) = 115–175 mg (145 mg average)

Case closed. Drip brew has the highest caffeine content and espresso the lowest. Well, in reality, it’s not that straight forward and is a little difficult to answer which brewing method has more caffeine because, I believe the answer depends on a lot of different factors…

Variety of Bean (robusta vs. arabica)
Robusta coffee beans have twice the caffeine content than arabica beans. Although arabica beans are considered to be of higher quality, robusta beans are used in many dark roast espresso blends… so, naturally, this will cause a higher caffeine content in espresso or any kind of blended (non-single origin) coffees that use robusta.

Roast level (light roast vs. dark roast)
Surprisingly, roast level impacts caffeine content. Dark roasted coffee is often associated with being “bold” and having a lot of caffeine, but that’s simply not true. The longer a coffee bean is roasted, the more the caffeine is burned off during the roast – so lighter roasts have a higher caffeine content than darker roasts. Since dark roasted coffee is generally used for making espresso, this impacts (lowers) the caffeine content.

Temperature of Water
Brew temperature is an important factor. Proper coffee extraction happens between 195-205 degrees, but most drip brewers only get up to about 190 degrees. Espresso machines usually do a good job brewing at near boiling temps. With french press coffee, you have total control over the temperature. If you want to pour boiling water (212 degrees) over your grounds, you can (but we don’t recommend it!). The point is, water temp. can vary by brewing method, and the hotter the water is, the better the extraction (to a point, please don’t exceed 205 degrees). With better extraction comes better tasting coffee, but also better caffeine extraction, too.

Amount of Ground Coffee Used
This one seems rather obvious, but I admit I didn’t really think about it until I wrote this post. The more coffee grounds you use, no matter your brewing method, the higher the caffeine content. Duh. But, it’s important to list as a variable, since some use more ground coffee than others when brewing based on taste preference.

Length of Brew Time
Another factor is the length of brew time. Generally speaking, drip brew coffee does have more caffeine than espresso. Why? Because with drip brew, hot water is continuously dripping through a bed of coffee grounds for 3 minutes. A shot of espresso is pulled in 20-30 seconds. Compared to drip brew, where coffee is in contact with hot water 6 times longer than the hot water that is in contact with coffee grounds during an espresso extraction, you can see how drip would have more caffeine. Not to mention with french press, and a recommended steep time of 4 minutes, more caffeine could potentially be extracted. It’s easy to see that, in terms of length of brew, drip brew coffee makes contact with hot water much longer than espresso does. But, if french press coffee steeps for 4 minutes, usually a minute longer than drip brew, how come french press coffee doesn’t have the highest caffeine content? The answer is the coarseness of the coffee grounds, which we speak to next.

Grind Level
The size of the grind makes a difference. For french press coffee, we use a coarse grind. For drip, a medium grind. Espresso, a fine grind. If you have a conical burr grinder, you may notice that you have to “dial in” the right grind to get your coffee to taste better. Maybe it’s too coarse, so you adjust the setting. Or it’s too bitter, so you adjust the setting to make it coarser. The finer you grind your coffee, the shorter the amount of time it will take to brew/extract, and if you leave all other variables the same (amount of coffee used, amount of hot water, brew length, etc.), a finer grind can mean more caffeine extraction.

Beverage Size
Sure, drip brew coffee generally has a higher caffeine content than espresso. But is that really comparing apples to apples? I mean, for drip brew, you could be using an 8 or 12 oz mug. Meanwhile, a shot of espresso could be 1.5 oz. Should we really be comparing the two the way we do? If we look at caffeine content per ounce, espresso would win. Just a thought.

What are your thoughts on coffee and caffeine? Are there any other variables you can think of that might influence caffeine content in these brewing methods? Let me know in the comments. -Ken

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Timing is everything… and the timing of when you grind your coffee beans matters. I’ve briefly mentioned it before, but there is a huge difference in the taste of brewed coffee when you brew within 60 seconds of grinding vs. brewing coffee with beans you ground the night before while setting up the coffee machine before bed (or worse, preground coffee). Here’s why…

The thing that makes coffee taste so good are the coffee oils found inside the coffee beans. During the coffee roasting process, sugars are caramelized and oils are formed and trapped inside the bean, encapsulated and protected from the outside world for a very short period of time. These coffee oils are essentially what gives brewed coffee its great taste.

In a perfect world, these oils would just hang out inside the bean indefinitely, but there are 2 forces working against these oils: carbon dioxide and oxygen. These two goons have a special assignment: destroy the coffee oils within 10 days, and if we let them, they’ll do just that – every time.

Let’s take carbon dioxide. One result of the coffee roasting process is that carbon dioxide is emitted from a freshly roasted coffee bean for about 2 weeks. The CO2 is the result of the volatile roasting process… think of it like a Pepsi can shaken up. It takes a little while for the Pepsi to normalize and the pressure to subside. Same thing with fresh roasted coffee – the coffee bean is in a volatile state and over the course of 10 days or so, the carbon dioxide slowly pushes the trapped coffee oils hiding inside the bean out to the surface, the oils escaping through cracks and crevices found throughout the interior and surface of the bean. The cracks are too small for oxygen to enter, so the carbon dioxide does the dirty work by forcing the oils out.

Now that the coffee oils are exposed on the surface of the bean, the second force – oxygen – takes over by attacking the oils and in a very small amount of time (30-60 minutes) the oils become rancid and if the beans are used, the resulting coffee will taste very stale and bitter.

With that background, it’s easy to see how ground coffee creates so much more surface area for oxygen to come in and do its thing. And not only do you have 30-60 minutes to brew your coffee after grinding, but 80% of any carbon dioxide left inside the coffee beans dissipate into the atmosphere within 60 seconds of grinding! CO2 is the main transport mechanism for pushing out any oils inside the bean casing into the water when we brew, so we really need to do what we can (brew quickly after grinding!) to use it to our advantage to get those oils out.

Try brewing within 60 seconds of grinding your coffee beans and I bet you’ll make a better tasting cup of coffee. -Ken

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You may not realize it, but the paper filters we use when brewing coffee in a drip-brewer or coffee dripper have a taste. A pretty disgusting taste, actually… like chewing on newspaper. Paper filters have soluble solids in them which are extracted during the brew process and this papery taste makes it into your cup. We’re so used to the taste that we don’t even notice it in our coffee anymore. But, if this filter taste was removed, we would notice the lack of paper taste in our brew, and we could get that much closer to attaining the perfect cup of coffee.

This can be done very easily! The best way, if using a drip-brew machine, is to place your filter in the coffeemaker (don’t add any coffee grounds yet!), add some water to the machine and start the brew cycle. You can use a small amount of water, about half a cup to a cup should do. The goal is to get some very hot water running through the filter to remove the paper taste. Dump the water after it cycles and start brewing your coffee like normal.

If you’re brewing with a manual pour-over dripper such as the Clever Coffee Dripper, just place the paper filter inside the dripper, place the dripper on top of your mug, and in a circular motion, pour water over the filter so that the entire thing gets wet. It doesn’t take much, and the quality of the pour matters much more than the quantity of water used. Cold water doesn’t work very well because the filter’s soluble solids (fibers, etc.), much like ground coffee beans, have a quicker extraction time the hotter the water is (that’s why french press with hot water takes 4 minutes and cold brewing takes 8-12 hours)… so, near-boiling water works best.

I typically use a coffee dripper when making coffee and when I pour hot water onto the filter, I can clearly see that the water that drips into my mug has a yellow tint and tastes very papery! Sometimes I forget to rinse the filter, especially if I’m half asleep… but, when I make a second cup, I taste a big difference when rinsing the filter. Try this for yourself. Make a cup of coffee the usual way. Then, do the rinse and make note of the yellow tint in the water. Take a small sip (gag!) and make note of what you taste. This is what cuppers (professional coffee tasters) do. They taste the good and the bad so they have experience and descriptors to use when saying why a coffee tastes good or bad. I bet if you use this rinsing technique you’ll taste a big difference in your coffee you brew at home.

One last note – in our last blog post, we discussed the importance of preheating your mug for better tasting coffee. This post ties in, as you can actually knock out both rinsing your filter and preheating your mug at the same time in most cases! The rinsed water is what would stay in your mug, keeping it hot, until you’re ready to dump it out and pour in a fresh brew. -Ken

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For many years I drank coffee without preheating my mug. I’d pour in the coffee into a room temperature mug (which actually tends to be a little cold by touch at room temperature), add some cold creamer, then would be really dissatisfied at the lukewarm brew I’d start sipping. Then I’d have to compensate by sipping a little coffee out and adding more of the brew to my mug (which would only marginally bring up the brew temp.) or, worse, I’d stick my mug in the microwave to make it hotter (hey, I know this is heresy… this was a long time ago!). Just like leaving coffee sitting on a warmer for 20 or 30 minutes, microwaving coffee actually changes the physical chemistry of the brew and degrades the quality of the resulting cup.

The fact is, I didn’t really understand too much about coffee back then or know anything about optimal brew temps. or what I could do to make better tasting coffee at home. Warm coffee can taste a lot different than hot coffee, as the flavors seem to change as coffee cools. The problem was, most drip-brew coffee makers, including the one I was using at the time, can only get up to about 190 degrees Fahrenheit at best, when optimal coffee extraction really takes place between 195-205. So, the coffee wasn’t brewing at the correct temperature in the first place, and the brew wasn’t making it into my cup at a decent temperature, either.

Besides my usual rant on how you can brew coffee at a more optimal temperature by using a french press, or our favorite pour-over method, the Clever Coffee Dripper, another suggestion on how to keep your coffee hotter is to preheat your mug before brewing your coffee.

This obviously doesn’t really work too well when pouring coffee into a paper cup, but when using a ceramic or travel mug, by preheating the mug, we can prevent the dramatic heat loss that happens when pouring a fresh brew of coffee into an otherwise cold mug.

Hot water from the tap isn’t hot enough. We need boiling or near boiling water for preheating. If you’re using a pour-over dripper, you can do this by placing your dripper on top of the mug and pouring some hot water through. This not only preheats your mug, but also the dripper, which can help maintain heat while brewing. If making coffee with a regular drip-brew coffee maker, you can also run some hot water through but since the brewer itself won’t usually get past 190 degrees, it may be better to put some water in your mug from the tap and microwave it for about 1:30 or boil water using a kettle… using a microwave is probably more convenient.

Leave the hot water in the mug until you’re ready to either start your dripping if using a pour-over method, or right before pouring in the brew from your drip-brew coffeemaker. Dump the hot water right before you start, and you’ll notice that the coffee in your mug will be a lot hotter than before…  you’ll likely taste flavors you may have never picked up on previously.

And, hopefully, you’ll never consider microwaving your cup of coffee again.

Give preheating your mug a try and let me know in the comments if you can taste a difference.

Although I’m partial to making coffee in a french press or a pour over cone dripper, many people still use regular old drip coffee brewers. And that’s OK. Maybe you don’t like the amount of sediment you get in your cup from using a french press (grind coarser, ::ahem::). Maybe the thought of brewing 1 cup at a time using a cone dripper seems like too much of a hassle, especially if you need to brew more than 1 cup of coffee at a time.

Perhaps you’re just not ready to move to the next level of your coffee journey just yet. Whatever the case may be, drip brewers are still one of the most common ways of brewing coffee in most people’s homes. I’m not a big fan, since optimal coffee extraction really happens around 195-205 degrees and drip brewers can typically only get up to about 190.

Still, there’s a simple hack you can use to make your drip brewed coffee taste better by leveraging the pause and serve feature (if your brewer has one… many do!).

The pause and serve is a feature introduced back in ’86 by Mr. Coffee drip coffee brewers where, while your coffee is brewing, it allows you to sneak a quick cup before the entire brewing process is complete by stopping the dripping of coffee for up to about a minute when the carafe is removed mid-brew. After pouring yourself a cup, and replacing the carafe back on top of the warming plate, the drip begins again.

The hack is simple… the filter basket, carrying the ground coffee, gets a continual showering of hot water, but never gets fully submerged with water such as in a french press. We’re going to change that. Wait about a minute after starting the brew process and pull the carafe out of the coffee maker, not to sneak a cup, but rather to allow that filter basket to fill up with hot water. Wait a good 45 seconds, then return the carafe to the warming plate… let the brewed coffee filter in to the carafe and give it about 30 seconds to “catch up”. Repeat 2-3 more times.

By doing this, you’re in effect making that filter basket fill up with hot water so the coffee grounds can steep, fully submerged, much like a french press. I think you’ll be really surprised by the results… you should notice a bigger body and richer flavor. Give it a shot and let me know in the comments if you tried this and how the resulting coffee tasted. -Ken

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When you see the disclaimer advising you to use cold water, it’s under the assumption that you are using tap water, from the sink – and if you use tap water, then you should use the cold water side of the tap. The reason is, cold water from the tap is fresh. Water from the hot side of the tap has likely been sitting around in your water heater for hours (or even days!) and is probably not fresh. Hot water heaters can have minerals and scale at the bottom of the tank that negatively impact the final taste of your coffee (and often the scale from the tank can greatly accelerate the buildup of limescale in your drip-brew coffee maker). To make great-tasting coffee, you have to use fresh water… so don’t use hot water from the tap!

What about filtered water from a pitcher, or bottled water? This water does not need to be cold to brew… so no need to use cold bottles of water or keep your pitcher in the refrigerator. This water is perfectly fine to use at room temperature.

As a side note, I have noticed an improvement in taste when using cold (not room temperature) water while brewing in a drip-brew coffee maker. Although I’m more of a french press, AeroPress or cone dripper kind of guy, occasionally I will break out our regular old drip-brewer to brew some coffee for family and friends. When using cold bottled water (as opposed to room temperature bottled water), the brewing time seems to be extended a good 45-60 seconds… which may not sound like much, but when brewing coffee, it can make a big difference as one drawback with drip-brewing is the length of time the coffee grinds steep with hot water being cut short. If you use a drip-brewer, try using very cold water the next time you make coffee and see if you notice a difference.

Please leave a comment below to continue the discussion and share this post with someone who enjoys good coffee. -Ken

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This morning, as I made myself a french press of coffee, roasted 3 days ago, I thought I would take a picture of the french press as it brewed. This picture is taken about 30 seconds after pouring near-boiling water on top of coffee, ground just seconds before. From the picture, you can see that this mini, 3-cup french press has a very tall crust!

You can see 3 layers here, a bottom layer of mostly liquid, a middle layer of water steeping with coffee grounds and a top layer of foam, bubbling as carbon dioxide is released from mixing with hot water. If you use stale coffee grounds, or even fresh coffee that hasn’t been properly stored or preground a while before brewing, you’ll likely just see the bottom and middle layers. When you see the top layer, you’ll know you’re getting the best tasting coffee possible. The carbon dioxide plays a huge role in transporting essential coffee oils (what makes coffee taste good) into your cup. Right click on the image above, left click on ‘view image’ then click again to zoom in and take a look at the crust. This is what you want to go for when making french press coffee. P.S. The mini 3-cup french press costs $2.99 at Ross (yes, the ‘dress for less’ place). 

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It’s important to note that I’m referring to pre-flavored beans… coffee beans that have flavoring added to them as soon as they’re out of the roaster and the beans are still warm to provide the best possible atmosphere for absorption of the flavoring. As you can image, the coffee bean – which encapsulates all of the coffee oils that make up the unique flavors of the bean – can be compromised by the application of the flavoring.

The flavoring can be natural or, more likely, chemicals that are engineered to taste like “hazelnut” or “vanilla”. For the flavoring to be applied evenly to warm, just roasted coffee beans, the flavored concentrate is diluted in solvents such as vegetable oil, water or even alcohol. After the application, water is then sprayed on the still warm beans to cool them off… however, this quenching process can also have negative effects on the coffee beans as the water allows some of the bean’s natural flavors to escape.

A roasted coffee bean itself has over 1,000 chemicals or compounds which make up it’s unique flavor. Adding flavoring to roasted beans can mute some of the natural chemicals that makes an origin coffee such as a Sumatra taste like a “Sumatra”.

Another reason that some coffee roasters add flavoring to just roasted coffee is to extend the shelf life. Fresh roasted coffee starts going stale after 10-14 days but when flavoring is added to coffee beans, the stale flavors resulting from oxidation and aging of the coffee beans can be diminished by the added flavoring, making it difficult for consumers to tell if the bitter flavor is due to old, stale beans or the quality compromise from pre-flavoring. Some roasters also take advantage of the flavoring process by using low quality coffee beans (low grade or even Robusta) as they believe the flavoring they’re adding to the coffee beans will make up for it.

Now, don’t get me wrong, some roasters do it right… they use high quality coffee beans, use natural flavoring, quench the beans with air rather than water. But for the most part, I believe flavoring coffee beans just out of the roaster does more harm than good.

What then can you do to flavor your coffee while maintaining quality?
Fresh roasted coffee provides more natural flavor and unique tastes than old, stale coffee… but for those who still want to add flavoring, I always recommend flavoring coffee once it has been brewed and is in your cup. In my opinion, this is the best way to maintain quality as the coffee beans haven’t been compromised by a roaster adding the flavoring themselves. You can taste the quality of the coffee and then add flavoring to your cup by using flavored creamer or natural flavored syrups to add the kind of tastes you’re looking for.

Another plus for adding flavoring to your cup after you brew your coffee vs. using pre-flavored coffee beans is you’ll have less maintenance on your blade and burr coffee grinders. Flavored coffee leaves flavor extracts on grinders which can cause a lot of damage and require repairs. This is one of the reasons why many local coffee shops, who gladly grind coffee for their customers, will not grind pre-flavored coffee (and if they do, they have a special grinder they’ve set aside just for these types of coffees).

Some additional tips
Use complimentary flavorings to enhance the flavor of your coffee. At Weekly Roast Coffee, we always indicate the natural, origin flavors we get out of testing the coffees we offer (for example, one coffee may have a sweet chocolate note while another, a hazelnut or vanilla note). In these cases, you could use flavoring in your cup to bring out or enhance the hazelnut or a different flavoring to compliment it.

Another idea, somewhere in between using pre-flavored coffee beans and adding syrups to your cup after it’s brewed, is to keep fresh roasted coffee in an airtight container along with mint leaves, cinnamon sticks, or anything else that gives off an aroma you’d like to taste in your coffee. This works well because coffee is porous, so it naturally absorbs the flavors around it (which is why we recommend that you do not store coffee in the fridge or freezer).

Please leave your comments below so we can continue the discussion and share this post with someone who enjoys good coffee. -Ken

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A lot of people believe that just because the beans were roasted dark and have a burnt taste, that means that the coffee is “stronger” and has more caffeine… but that isn’t exactly the case.

The quick answer is that for the most part, lighter roasts actually have more caffeine than darker roasts. When coffee beans are roasted, the beans undergo a series of physical changes including growing in size, becoming lighter in weight but also burning off some caffeine. The longer the beans are roasted (the darker the beans), in general, the less caffeine they will have solely due to them having more and more caffeine being burned off.

Now, it does get a bit more complicated than that. I mentioned that the longer coffee beans are roasted, the lighter they become (weight loss) so a pound of lightly roasted coffee could potentially have about the same caffeine content as a pound of dark roast (for example, a french roast coffee), simply because it would take more beans of a dark roast (going by weight) to make a pound. But, in general, taking 2 pounds of the exact same coffee – roasting one pound lightly and one dark – and not adding more beans to the darker roast to account for the weight loss due to roasting longer – the lighter roast will usually have more caffeine.

What kind of coffee beans have more caffeine?
In my blog post on Arabica vs. Robusta coffee beans, I noted that Robusta beans have a higher caffeine content than Arabica beans (about twice as much!). The downside, though, is that Robusta beans taste pretty awful. They are used by some roasters in coffee blends, sometimes as filler and sometimes for espresso blends solely due to their caffeine content. Since Arabica beans are associated with higher quality and better taste, Arabica is what you’ll likely find in your neighborhood coffee house or offered by a premium coffee roaster.

Which has more caffeine, espresso or drip brew coffee?
While on the topic of espresso, it’s important to note that, not only do dark roasts generally have less caffeine than light roasts, but espresso also has a lower caffeine content than drip brew! The reason is the length of time that the coffee beans are in contact with water for extraction. With espresso, the coffee may be in contact with water for 25 seconds or so. When making coffee via a drip-brew method, or even in a french press, coffee is in contact with water for a much longer period (up to 4 minutes). The extended time of the coffee being in contact with hot water is what allows more of the caffeine to make its way into your cup.

So the next time you want that caffeine “buzz” think twice before ordering that espresso or dark, french roast… and consider trying a lighter roast drip-brew or french press instead.

Please leave your comments below so we can continue the discussion and share this post with someone who enjoys good coffee. -Ken

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This is normal and is a byproduct of grinding coffee beans, as residual oils from coffee beans (especially dark roasts which typically cause the greatest amount of oil on the coffee beans) get trapped inside the grinder along with coffee grounds from prior grinds.

Ground coffee goes stale within 30 minutes of grinding and coffee oils go stale (rancid, really) very quickly. Anything left in your grinder will degrade the next batch of coffee you put through the grinder as old, rancid oils and stale ground coffee mix with newly ground coffee which ultimately get put back into the cup you brew. This cycle repeats itself and snowballs until the grinder is either cleaned properly or breaks down due to the stale ground coffee and coffee oils causing problems, such as slowing the machine down, meanwhile the cup you brew gets continually worst.

How should you clean your coffee grinder?
A really great way to clean out your grinder is to use uncooked, white rice. If you use a blade grinder (and we highly recommend upgrading to a burr grinder!), fill it with white rice up to the blades. If you use a burr grinder, put about 2-3 teaspoons worth of white rice and set the burr grinder to a fine grind (espresso) setting and start grinding.

After you’ve finished grinding, you’ll notice immediately that large clumps of previously ground coffee are now clinging to the powdered, ground white rice and after dumping the grounds out, you should see spots you could never clean before coffee-ground free. The inside of the grinder should also be a lot cleaner than before as most of the old, rancid coffee oils also attached themselves to the white rice (they’re attracted to the starch in the rice – that’s why this technique works so well).

Repeat this process until the ground rice no longer has any black particles in it. The first run will get most of the bigger coffee particles out. Subsequent runs will further clean the grinder. After the rice you run through the grinder no longer picks up any coffee residue and is just as white coming out as it was going in, run a small batch of coffee through the grinder… but use some cheap or not-so-fresh coffee you don’t mind getting rid of. The point here is to get rid of any remaining rice particles left in the grinder with this final run of low quality coffee so new batches come out tasting great.

Hope this helps you make a better brew. Please leave your comments below and share this post with someone who enjoys good coffee. -Ken

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