### Author Topic: Caffeine in a coffee stout  (Read 591 times)

#### MWY608

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• Posts: 2
##### Caffeine in a coffee stout
« on: February 09, 2020, 01:09:22 AM »
I was wondering if there was a way to figure out how much caffeine would be in a homebrew if coarse ground dark roasted coffee was put into the secondary for a 12 days? 5 gal batch, think I used 3oz.

thanks,
mike

#### chezteth

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##### Re: Caffeine in a coffee stout
« Reply #1 on: February 09, 2020, 02:24:52 AM »
I was wondering if there was a way to figure out how much caffeine would be in a homebrew if coarse ground dark roasted coffee was put into the secondary for a 12 days? 5 gal batch, think I used 3oz.

thanks,
mike

I don't know how to exactly calculate the caffeine content in your beer. However, let's give it a whirl.

I would use 3oz of medium grind coffee for 10 cups (60 floz) of drip coffee. Assuming one 8oz cup has 120mg of caffeine then the 10cups of coffee would have approximately 900mg of caffeine. Now, from what I understand that caffeine dissolves into solution better in hot water than cold. Also, dark roasted coffee has less caffeine than light roasted coffee. And, coarse ground coffee won't give up as much caffeine either. So, the actual number may be less.

I understand some people are concerned with the amount of caffeine in beer that has had coffee added to it. If we take this a bit further 900mg of caffeine in 5gal of beer would yield approximately 17mg of caffeine per 12oz of beer. That is less caffeine than a cup of tea. Almost as small of an amount as a cup of decaf coffee (approx 7mg). Of course, this is all estimates based on calculations. I hope this helps.

#### goose

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##### Re: Caffeine in a coffee stout
« Reply #2 on: February 09, 2020, 06:47:03 PM »
I don't ever grind the beans. I just add them to the secondary as whole beans.  This minimizes caffeine extraction (I get very little, if any) but still get the full flavor from the coffee.

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#### MWY608

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##### Re: Caffeine in a coffee stout
« Reply #3 on: February 10, 2020, 01:55:24 AM »
I figured it wouldn't be a lot of caffeine, but wanted to see what people thought.
might try not grinding the beans next time and see if I still get the coffee taste im looking for.

Thanks for the info.

#### goose

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##### Re: Caffeine in a coffee stout
« Reply #4 on: February 13, 2020, 02:35:22 PM »
I figured it wouldn't be a lot of caffeine, but wanted to see what people thought.
might try not grinding the beans next time and see if I still get the coffee taste im looking for.

Thanks for the info.
Be sure to taste the beer so you don't overdo the coffee.  I only go for about 3 days.  Five days was a bit much for me.

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#### Visor

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##### Re: Caffeine in a coffee stout
« Reply #5 on: February 13, 2020, 05:55:02 PM »
Something to keep in mind, at least from my experience is that like hop aromas and flavors, the coffee will fade over time. Stout is a beer that frequently is kept longer than some others, so you need to decide whether you want it just right when the beer is fresh, or when it's 2 years old.
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#### JoanMCD

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##### Re: Caffeine in a coffee stout
« Reply #6 on: March 17, 2021, 11:45:35 AM »
Guys, how do you think does Guinness stout has caffeine? I know it hasn't, but my friend says that it has...As I know there are flavours that come from the beer that are coffee-like. I have read that the only ingredients in Guinness are Barley, Hops, Water and Yeast. Maybe I'm wrong? My friend convinces me that to make Guinness, I should definitely add the best decaf coffee for flavour and coffee taste. I would be grateful if you share your knowledge and help us solve this issue. Thanks in advance!
« Last Edit: March 20, 2021, 08:14:51 AM by JoanMCD »

#### denny

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##### Re: Caffeine in a coffee stout
« Reply #7 on: March 17, 2021, 03:13:18 PM »
Guys, how do you think does Guinness stout has caffeine? As I know it hasn't, but my friend says that it has...

It does not.
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#### majorvices

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##### Re: Caffeine in a coffee stout
« Reply #8 on: March 17, 2021, 03:17:14 PM »
Guys, how do you think does Guinness stout has caffeine? As I know it hasn't, but my friend says that it has...

It does not.

The website says it has "naturally occurring caffeine" so I am assuming it does have some. Even decaf coffee has some caffeine in it.

#### denny

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##### Re: Caffeine in a coffee stout
« Reply #9 on: March 17, 2021, 03:37:07 PM »
Guys, how do you think does Guinness stout has caffeine? As I know it hasn't, but my friend says that it has...

It does not.

The website says it has "naturally occurring caffeine" so I am assuming it does have some. Even decaf coffee has some caffeine in it.

I stand corrected.  Wonder what the source is?
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#### erockrph

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##### Re: Caffeine in a coffee stout
« Reply #10 on: March 17, 2021, 05:02:19 PM »
Guys, how do you think does Guinness stout has caffeine? As I know it hasn't, but my friend says that it has...

It does not.

The website says it has "naturally occurring caffeine" so I am assuming it does have some. Even decaf coffee has some caffeine in it.
Do you have a link to the page on their site that states this? I don't see any mention of this on the pages I've viewed.

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#### majorvices

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##### Re: Caffeine in a coffee stout
« Reply #11 on: March 17, 2021, 05:24:44 PM »
Guys, how do you think does Guinness stout has caffeine? As I know it hasn't, but my friend says that it has...

It does not.

The website says it has "naturally occurring caffeine" so I am assuming it does have some. Even decaf coffee has some caffeine in it.
Do you have a link to the page on their site that states this? I don't see any mention of this on the pages I've viewed.

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I did a search. I found that information it said "Contains natural coffee and coffee flavors. Caffeine occurrence it natural"

#### denny

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##### Re: Caffeine in a coffee stout
« Reply #12 on: March 17, 2021, 05:46:13 PM »
Guys, how do you think does Guinness stout has caffeine? As I know it hasn't, but my friend says that it has...

It does not.

The website says it has "naturally occurring caffeine" so I am assuming it does have some. Even decaf coffee has some caffeine in it.
Do you have a link to the page on their site that states this? I don't see any mention of this on the pages I've viewed.

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I did a search. I found that information it said "Contains natural coffee and coffee flavors. Caffeine occurrence it natural"

Obviously, Guinness coffee stout does.  But I thought we were discussing the regular Guinness.  (reply #6) https://www.quora.com/Does-Guinness-have-caffeine
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#### RC

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##### Re: Caffeine in a coffee stout
« Reply #13 on: March 17, 2021, 06:05:40 PM »
Guys, how do you think does Guinness stout has caffeine? As I know it hasn't, but my friend says that it has...

It does not.

The website says it has "naturally occurring caffeine" so I am assuming it does have some. Even decaf coffee has some caffeine in it.
Do you have a link to the page on their site that states this? I don't see any mention of this on the pages I've viewed.

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I did a search. I found that information it said "Contains natural coffee and coffee flavors. Caffeine occurrence it natural"

Guinness stout (the regular stout) does not contain coffee, natural or otherwise.

Around 60 or so plants are known to produce caffeine, but barley and hops are not among them. It's nonetheless conceivable that trace amounts of caffeine might be found in barley and hops tissues. Any such caffeine would originate in other plants that might be growing, either intentionally or accidentally, alongside/within the barley and hops fields. When these plants die or drop leaves, the caffeine in their tissues would leach into the soil and could be uptaken by the barley or hops, resulting in "naturally occurring caffeine." I have no idea about the specific farming practices involved in growing barley or hops, so this is just conjecture. The point is, whatever is in the soil will also be found in the plants growing in the soil.

As a side note, caffeine is made by some plants that you might not expect: citrus plants, for instance, produce small amounts of caffeine in their flowers. It has been shown to improve the memories of the bee pollinators. None of it ends up in the fruit, though. And the common garden bush Camellia sinensis has long been known to produce it.

#### erockrph

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##### Re: Caffeine in a coffee stout
« Reply #14 on: March 17, 2021, 06:17:25 PM »

.

As a side note, caffeine is made by some plants that you might not expect: citrus plants, for instance, produce small amounts of caffeine in their flowers. It has been shown to improve the memories of the bee pollinators. None of it ends up in the fruit, though. And the common garden bush Camellia sinensis has long been known to produce it.
Camellia sinensis is the tea plant. I don't know if I'd call it a common garden bush (although I do have one myself).

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Finally got around to starting a homebrewing blog: The Hop Whisperer