Sign up for the Single Serve Coffee mailing list and be eligible to win prizes given away to mailing list members.

What is the Caffeine Content of Single-Serve Coffee?

General coffee information, history, growing regions, types, caffeine, home roasting, storage, etc.

Moderators: jbviau, NDJollyMon

What is the Caffeine Content of Single-Serve Coffee?

Postby transonik » Fri Dec 08, 2006 12:59 pm

I just searched the forums and was surprised to find no discussion of this topic.
The best post I found is reproduced below, so that responses to this one don't re-cover the same old grounds.

My Keurig first produces output 10 seconds after hitting 'Start', and doesn't drip another drop after 35 or 40 seconds. My drip maker takes about 600 seconds for an 8-cup pot. What effect does the high-speed brew have on caffeine content? Surely not 40/600 ths!! (which would be 7%, or 7mg of caffeine for every 100mg in some reference dripmaker cup)

A Wikipedia 'Caffeine' footnote is relevant, but it addresses repeated steepings of tea, and deals in a time granularity of "about 5 minutes".
http://www.nobleharbor.com/tea/caffiene.html

Lots of folks speculate that steeping time impacts caffeine content. OK, I'll guess that it does too. But how much? Google doesn't seem to know, and I emailed Customer Service at Keurig a week ago and have received no reply at all.

My guess is that single-serve coffee has about half the caffeine of drip.

=================== Best Prior Post, 4.8.2006 ===================
goodjava

Joined: 07 Nov 2005
Posts: 141

PostPosted: Sat Apr 08, 2006 2:39 pm Post subject: Re: Musings on Caffeine Reply with quote
Ingrid these are great questions that I think if we get answered to our satisfaction then the discussion on these forums will be a lot clearer. Also a great weekend discussion. Below is how I think about the points you bring up. Hopefully others will chime in and correct my errors and we can all get on the same page.

In general I believe that a stronger cup of coffee will have more caffiene. To me a stronger cup of coffee is one with a higher amount of the coffee oils and solids extraxted into a given volume. So the more coffee extracted the higher the caffeine. This would be true regardless of the type of bean extracted. To my mind the biggest misconception, and this has now been discussed in a number of topics here, is that many relate strength of the brew and darkness of the roast. To me strength and roast level have no relationship, strength is determined by extraction of coffee oils and solids and roast is a factor that dermines flavor.

There is more caffeiene in green beans than roasted beans and more in a light roast than a dark roast. The heat required for roasting can break down caffeine. I don't know what the difference is as a percentage change through each stage, maybe someone else can help us out there. There are a number of other things that can affect this. How do you grind and measure your coffee? There is more water removed as you continue roasting, so the amount of coffee for a given weight will be different, this will make a pretty small difference for the amount of coffee we prepare at one time. The finer you grind the more coffee you can get into a given volume such as the standard scoop measures that come with coffee machines. I think this would make a bigger difference to the general methods of prpearing coffee. Also how you make your coffee will give different extraction and therfore change caffeine levels. French press will be higher than drip or any of our single serve machines.

The type of beans make a big difference. The main one is that robusta beans (the type in the much cheaper supermarket isles) have more caffeine than arabica beans (the stuff with the great flavor that we all crave). The caffeine levels will vary a little within these two type of beans because of slight varrietal differences and more importantly different growing conditions.

To me the "espresso effect" is all marketing. Espresso is my preferred drink and I think there is less caffeine. In someways it mirrors the Starbuck effect that has happened. Starbucks have very dark roasts and have relied on the darker equals stronger equals more caffeine misconception I mentioned earlier.

We all have different physiology and our own physiology changes. So yes you can develop tolerances to caffeine, and how caffeine affects you now may be different to how it used to affect you and how it may affect you in the future. But it is having an effect. Try giving it up for a week and see how many Advil you go through. Headaches are the most common withdrawal symptom.

I don't choose a particular coffee solely for its caffeine. My guess is that most on these forums are so interested in coffee that they are here for flavor first and caffeine way down the list, probably second. Wink If you were to select for caffeine first I would recommend your favorite commercial, comes in a big can, brand of coffee that is light to medium roast and has a high level of robusta beans. If you brew that up in your French Press you should get a good jolt. Flavoring coffee has no effect on caffeine levels it is all determined by the coffee used. In fact often lighter roasts are used so caffeine may be higher.

Decaf will taste different because of the caffeine extraction process. It uses solvents or water to remove caffeine from the beans. The caffeine is removed from this soup then they try to return the flavor components to the beans. There is no way you can do this without altering the flavor of the bean. than doesn't mean that you won't find some very drinkable decafs, there are many of them. But bottom line is that in general the untreated bean will taste better than the treated bean, so we go back to caffinated beans more often.
transonik
 
Posts: 3
Joined: Fri Dec 08, 2006 12:30 pm

Postby NDJollyMon » Fri Dec 08, 2006 1:26 pm

Great question. If I were to guess, I'd say you are probably on the right track. I get real jittery when I have too much caffeine. I didn't notice much of a change in my 'jittery-ness' when I switched to Single Serve coffee. (after an equal amount of coffee)

Maybe Jim, DeCad, or David can shed some light on this subject?
Pete (Jolly Mon) -
Forum Moderator
____________
Keurig: B130 ~ B-60 SE
Cuisinart SS-1
Handpresso Wild
Behmor 1600 Coffee Roaster
Baratza Maestro Plus grinder
Aeropress
Bodum French Press
User avatar
NDJollyMon
 
Posts: 3399
Joined: Wed Oct 12, 2005 8:58 pm
Location: ND, USA...help!

Postby gentgeen » Fri Dec 08, 2006 4:04 pm

Gentgeen puts on his chemist hat

Of the compounds in coffee, caffeine is one of the more soluble in water. As a result, almost all of the caffeine is extracted in the first ounce or two of a single serve drop. The coffee solids and oils are much less soluble, and are extracted more slowly.

This is the basis behind many decaffination processes. Caffeine and other water soluble compounds are disolved from the coffee, another substance selectivly removes the caffeine from the coffee solution, and then the solution is reintroduced to the beans (or the next batch of beans). Swiss water process uses activated charcoal to grap the caffeine, others use ethyl acetate or another organic solvent.

The higher pressure (even if it's not 9 atmospheres) and finer grind used in a single serve machine improves the solvation rate of all the substances, which lets the coffee be produced in less time. This also explains the change in body (mouth feel) of the coffee, as this rate improvement isn't uniform for all the compounds in a coffee bean.

John
Batterie de Café

Tassimo TA1400
Juan Valdez JVPM2B
Bodum Brazil 350 ml French Press
Senseo HD7810/75 (blue) (held in reserve)
gentgeen
 
Posts: 154
Joined: Tue Oct 25, 2005 1:15 am
Location: San Jose, California

Postby transonik » Fri Dec 08, 2006 4:17 pm

Gentgeen - So your estimate is that the caffeine content is almost as much as a 10-minute drip process?

The reference to 9 atmospheres of pressure - is that what an expresso machine applies? Do single serve machines exceed room pressure? The Keurig makes a bit of a puffing sound, which might be an atmosphere or so....

Do you expect the tea steeping article I originally posted to be a rough guide to the extraction rate, or is the solubility of caffeine different in tea and ground coffee beans?
transonik
 
Posts: 3
Joined: Fri Dec 08, 2006 12:30 pm

Postby darrylr » Fri Dec 08, 2006 10:32 pm

On the other hand it's well known that espresso drinks have less caffein than drip coffee, so it's not at all clear to me that faster extraction, finer grind, and higher pressure result in more caffein extraction. The evidence of espesso (which as all those brew characteristics) suggests the opposite. It would probably be because of the faster extraction of an espresso versus a drip brew so I might expect single serve coffee to also have less caffein than drip brew.

Darryl
darrylr
 
Posts: 263
Joined: Wed Aug 31, 2005 3:51 am

Postby The Lone Podster » Fri Dec 08, 2006 10:40 pm

Many moons ago, I was told (or read) that espresso had less caffeine than drip, because it was brewed faster. Just my t :shock: cents.

Podster.
Grindmaster OPOD x2 (retired)
Freshroast Plus 8, HG/BM roaster
Behmor 1600
Bodum Brazil 12 oz. French Press
Bodum Bistro Double Wall 34 oz. French Press
Eva Solo CafeSolo, Clever Coffee Dripper
Technivorm KBT 741
Baratza Maestro Plus
User avatar
The Lone Podster
 
Posts: 1489
Joined: Mon Jan 23, 2006 10:20 am
Location: Pittsburgh

Postby Alice2 » Sat Dec 09, 2006 12:29 am

Some people are more sensitive to caffeine than others. I never thought about the Keurig or Bunn making a less-caffeinated cup or more so than a regular drip brewer. After all, it's just regular coffee, with both run-of-the mill and exotic coffees available for all tastes.

I know the decaf fans are all wishing there was better selection in decaf varieties, but caffeine just doesn't bother me.

In fact, it's time for 7:30pm cup right about now as I only had one after work --- full caffeine! :lol:

When I was young I'd often get the coffee jitters, but not anymore. I was starting to think it was the acid level from canned grocery store coffee that gave me the shakes, and not the caffeine itself. Not sure tho!
KitchenAid Single-- Keurig B30 red-- Keurig B30 black (non-leaking version)-- KitchenAid Compact 4-Cupper ('cute lil' red coffeemaker)-- Mr. Coffee Drip (don't ask why, it just is.) I nailed a re-tread to my feet and I prayed for better weather
User avatar
Alice2
 
Posts: 2428
Joined: Fri Mar 17, 2006 5:30 pm

Postby gentgeen » Sat Dec 09, 2006 2:19 am

Ah, now we're getting into other areas. I did say "most" of the caffeine is extracted in the first ounce or two, but not all of it. So a 1.5 oz espresso would have a somewhat reduced caffeine content. In addidtion, steam denatures caffeine, as does darker roasting. Espresso is normally a rather dark roast, and the machines are driven by steam, which exposes the grounds to some during processing. Additionally, when the coffee gets through the coffee puck, the resulting drop in pressure causes some of the water to quickly evaporate into steam, destroying some more caffeine. Combined, these different variables result in a shot of espresso having less caffeine than a cup of coffee, but still more than a cola. If I remember correctly, it's 30-50 mg for a can of cola, about 40- 70 for an espresso, and 100 for a cup of coffee.

John
Batterie de Café

Tassimo TA1400
Juan Valdez JVPM2B
Bodum Brazil 350 ml French Press
Senseo HD7810/75 (blue) (held in reserve)
gentgeen
 
Posts: 154
Joined: Tue Oct 25, 2005 1:15 am
Location: San Jose, California

Postby transonik » Sat Dec 09, 2006 10:19 am

Nine atmospheres is the pressure of a racing bicycle tire. A car tire is only 2 atm. But sure enough, expresso machines do run the brew under roughly 9 atm!

An expresso machine brews in 25 - 30 sec, which is very nearly the time of a single-serve machine. But the pressure, temperature, and grind differ.

I'd expect those differences to reduce the caffeine content per milliliter, but of course we drink much larger cups of coffee than expresso.

So I'm still speculating that a single serve cup has about half as much caffeine as a drip-brewed cup of the same blend.
transonik
 
Posts: 3
Joined: Fri Dec 08, 2006 12:30 pm

Postby goodjava » Sat Dec 09, 2006 11:39 am

I think Gentgeen has summarized it pretty well. Single serve machines may be a little lower, but I would be suprised if it was too much lower. My guess would be a few percent lower certainly not half. There are many things that affect the coffee extraction process, but as Gentgeen said since caffiene is water soluble it is one of the easier things to extract. Overall you will get more extraction from higher temperature, but below boiling. Higher pressure. More time. Smaller grind. More coffee.
So 600 seconds for eight cups is about 75sec per coffee serving. (That is a very fuzzy number because of the way drip brewers work, but lets go with it). SSC machines average about half the time. Temeperature should be comparable between the machnes. Pressure is slightly higher in most of the SSC machines since they use pumps to force the water through ( we are talking a couple of atmospheres at most, nothing like an espresso machine). Coffee amount is similar but probably a bit higher in the drip machines, lets face it we all add that extra spoonfull at the end, right? Grind size should be a bit smaller in the SSC machines.
So I don't see any great advantage for either process, I think either way we will stay appropriately caffeinated.

Now if we could just get some lightly roasted robusta beans that would could brew for a longer time under a little pressure :shock:
goodjava
 
Posts: 155
Joined: Mon Nov 07, 2005 1:49 am

Postby darrylr » Sun Dec 10, 2006 11:54 am

gentgeen wrote:the machines are driven by steam, which exposes the grounds to some during processing. Additionally, when the coffee gets through the coffee puck, the resulting drop in pressure causes some of the water to quickly evaporate into steam, destroying some more caffeine.


That is completely incorrect. Except for mocha pots and certain very cheap espresso machines, espresso machines are driven by a pump feeding water heated to about 200 degrees. Thus the puck is exposed only to hot water, and that water does not steam any due to the pressure drop in the puck because the water is always well below the boiling point. Any amount of "steam" released by the water is what would happen with any stream of water dropping at that temperature.

Regarding darker roasts having less caffeine that is true, however not all espresso uses dark roasted coffee, just as not all drip coffee is lighter roasted coffee. In fact where is there any data that says that the average drip brew is done with lighter roasted beans than is typical of espresso. The majority of coffee consumed in this country, and I believe in Europe, leans toward darker roasts.

Darryl
darrylr
 
Posts: 263
Joined: Wed Aug 31, 2005 3:51 am

Postby Bettercoffee.com » Sun Dec 10, 2006 9:45 pm

Hmm.... after not necessarily reading all these lengthy posts in their entirety, I have the following to offer regarding the caffeine content in coffee:

light roast has MORE caffeine than dark
weak (more water) coffee has MORE caffeine than strong
coffee has MORE caffeine than espresso

Caffeine is indeed water soluable, and SWP decaf is just that: they simply run water through the beans for weeks on end to wash away the buzz (and the flavor). Regular non-SWP decaf preserves the flavor better, but uses chemicals with scary sounding names.

My bet would be the SSC has slightly less caffeine than drip, since the water is forced through under pressure and therefore has less time to comingle with the grounds and dissolve the caffeine. On this though, I'm guessing.

--David
http://www.bettercoffee.com/

Now offering SINGLES for our ENTIRE catalog. Try just one of any flavor!
User avatar
Bettercoffee.com
 
Posts: 753
Joined: Wed Jul 27, 2005 11:03 pm
Location: Rochester, NY

Postby Marci » Sun Dec 10, 2006 9:51 pm

I am very sensitive to caffeine. I find with SSC pods/k-cups, I am less wired which is a good thing! I also like dark roasts which help. I stay way from light roasts for this very reason.
User avatar
Marci
 
Posts: 1763
Joined: Sat Jul 30, 2005 1:18 pm
Location: California

Postby NDJollyMon » Mon Dec 11, 2006 1:19 am

I'm scared of the dark...
Pete (Jolly Mon) -
Forum Moderator
____________
Keurig: B130 ~ B-60 SE
Cuisinart SS-1
Handpresso Wild
Behmor 1600 Coffee Roaster
Baratza Maestro Plus grinder
Aeropress
Bodum French Press
User avatar
NDJollyMon
 
Posts: 3399
Joined: Wed Oct 12, 2005 8:58 pm
Location: ND, USA...help!

Postby Bucfanmike » Mon Dec 11, 2006 1:46 am

Marci wrote:I am very sensitive to caffeine. I find with SSC pods/k-cups, I am less wired which is a good thing! I also like dark roasts which help. I stay way from light roasts for this very reason.


Well also just because they taste bad
Hi, Im Mike and I have an addiction...
i have tried them all and ended up with:
Nespresso Romeo E350,
Grindmaster OPOD, Toddy Cold Press, Cuisinart ss-1
and now home roasting with HG/BM method
User avatar
Bucfanmike
 
Posts: 1517
Joined: Fri Dec 23, 2005 6:26 pm
Location: Duluth, MN

Next

Return to Coffee 101

Who is online

Users browsing this forum: No registered users and 0 guests