Comments on: The naturals debate http://www.jimseven.com/2010/02/10/the-naturals-debate/?utm_source=rss&utm_medium=rss&utm_campaign=the-naturals-debate James Hoffmann's blog. Thu, 29 Jul 2010 14:10:57 +0000 hourly 1 By: coffee@home: Scarlet City Coffees « Man Seeking Coffee http://www.jimseven.com/2010/02/10/the-naturals-debate/#comment-99307 coffee@home: Scarlet City Coffees « Man Seeking Coffee Sun, 18 Jul 2010 07:07:32 +0000 http://www.jimseven.com/?p=1483#comment-99307 [...] is the kind that jumps out at you on the cupping table. It’s also the type of coffee now deemed passe by many coffee greats. One glance at Scarlet City’s Amaro Gayo and I was doubly convinced that this coffee was not [...] [...] is the kind that jumps out at you on the cupping table. It’s also the type of coffee now deemed passe by many coffee greats. One glance at Scarlet City’s Amaro Gayo and I was doubly convinced that this coffee was not [...]

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]]> By: Mike Marquard http://www.jimseven.com/2010/02/10/the-naturals-debate/#comment-98702 Mike Marquard Tue, 06 Apr 2010 16:26:58 +0000 http://www.jimseven.com/?p=1483#comment-98702 Nayarita is a great example to examine. They produce washed and natural coffees of high caliber. What I found extremely interesting is that when we carried both coffees in our cafes, side by side, our baristas were head-over-heals for the natural. While most of us at the roasting facility favored the washed coffee for its balance and cleanliness, there is something to be said for the accessibility and saturation of taste notes in naturals, even if they are fairly one-dimensional. The barista's ability to hone in on a flavor and then translate that to the customer's experience really increased the sales of the natural coffee. Maybe (and this is unqualified opinion), we need to teach farmers how to better exploit this demand for natural coffees. If it is more risky, can they raise their price........or ....will the consumer pay more for a natural version of a beloved coffee? Nayarita is a great example to examine. They produce washed and natural coffees of high caliber. What I found extremely interesting is that when we carried both coffees in our cafes, side by side, our baristas were head-over-heals for the natural. While most of us at the roasting facility favored the washed coffee for its balance and cleanliness, there is something to be said for the accessibility and saturation of taste notes in naturals, even if they are fairly one-dimensional. The barista’s ability to hone in on a flavor and then translate that to the customer’s experience really increased the sales of the natural coffee.

Maybe (and this is unqualified opinion), we need to teach farmers how to better exploit this demand for natural coffees. If it is more risky, can they raise their price……..or ….will the consumer pay more for a natural version of a beloved coffee?

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]]> By: samuli marila http://www.jimseven.com/2010/02/10/the-naturals-debate/#comment-98680 samuli marila Tue, 30 Mar 2010 09:33:56 +0000 http://www.jimseven.com/?p=1483#comment-98680 a quick question, does drying of naturals occur in big greenhouses, with good ventilation, were temps could be high enough to prevent the "negative" impact? can it be done? i imagine it happening in brazil but have only seen it done on patios, covered and not. a quick question, does drying of naturals occur in big greenhouses, with good ventilation, were temps could be high enough to prevent the “negative” impact? can it be done? i imagine it happening in brazil but have only seen it done on patios, covered and not.

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]]> By: Peter G http://www.jimseven.com/2010/02/10/the-naturals-debate/#comment-98678 Peter G Mon, 29 Mar 2010 22:11:14 +0000 http://www.jimseven.com/?p=1483#comment-98678 Hey Tom- I sent you and James both copies of a couple of papers written on this topic. For the sake of this discussion, though, I would like to point out: My point in the initial post was that yeasts and other microorganisms certainly contribute to flavors in the fermentation tank, which transfer into the coffee itself. This is a separate process to the process (also microbiological) that drives mucilage detachment. Whether or not specific yeasts are responsible for the mechanical detachment of mucilage (Avallone seems to think that lactic acid bacteria are generally responsible for that) there is no question that yeasts are active in metabolizing sugars into alcohol and carbon dioxide in the fermentation tank during even short fermentations. Yeasts are the most common microorgansm on plant surfaces, and are often the most common microorganism in the air. Any sugar- and moisture- rich plant material (like mucilage) will be instantly inocculated with yeasts. Yeasts turn sugar into alcohol, and acetobacter turn that alcohol into acetic acid; that's one way we get acetic acid in coffee. At the same time, lactic acid bacteria turn sugar into lactic acid. There are lots of yeasts in the world. Let's take one for example, candida lambica. This is a yeast that has been found in microbial studies of naturally fermenting coffee mucilage (Avallone et al, 2002). It is also present in the Belgian wild yeasts used to make Lambic Beer (hence the name). Anyone who has made a lambic at home will tell you that those yeasts kick in within a few hours, and are really active within 12 hours, metabolizing that sugar into strongly flavored compounds. I have seen fermentation tanks in Ethiopia bubbling away with CO2, clearly showing all the signs of yeast activity. The role of yeasts and other microorganisms is really complex, and is probably the source of incredibly interesting research. I hope this kind of research gets done in the future! Peter G Hey Tom-

I sent you and James both copies of a couple of papers written on this topic. For the sake of this discussion, though, I would like to point out:

My point in the initial post was that yeasts and other microorganisms certainly contribute to flavors in the fermentation tank, which transfer into the coffee itself. This is a separate process to the process (also microbiological) that drives mucilage detachment.

Whether or not specific yeasts are responsible for the mechanical detachment of mucilage (Avallone seems to think that lactic acid bacteria are generally responsible for that) there is no question that yeasts are active in metabolizing sugars into alcohol and carbon dioxide in the fermentation tank during even short fermentations. Yeasts are the most common microorgansm on plant surfaces, and are often the most common microorganism in the air. Any sugar- and moisture- rich plant material (like mucilage) will be instantly inocculated with yeasts. Yeasts turn sugar into alcohol, and acetobacter turn that alcohol into acetic acid; that’s one way we get acetic acid in coffee. At the same time, lactic acid bacteria turn sugar into lactic acid.

There are lots of yeasts in the world. Let’s take one for example, candida lambica. This is a yeast that has been found in microbial studies of naturally fermenting coffee mucilage (Avallone et al, 2002). It is also present in the Belgian wild yeasts used to make Lambic Beer (hence the name). Anyone who has made a lambic at home will tell you that those yeasts kick in within a few hours, and are really active within 12 hours, metabolizing that sugar into strongly flavored compounds. I have seen fermentation tanks in Ethiopia bubbling away with CO2, clearly showing all the signs of yeast activity.

The role of yeasts and other microorganisms is really complex, and is probably the source of incredibly interesting research. I hope this kind of research gets done in the future!

Peter G

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]]> By: Price http://www.jimseven.com/2010/02/10/the-naturals-debate/#comment-98677 Price Mon, 29 Mar 2010 21:47:20 +0000 http://www.jimseven.com/?p=1483#comment-98677 For some years we also were interested in whether fermentation or enzymes. Several years ago, to test the notion, we checked temperature change during 'fermentation' and there was NO significant change. Next we tried adding a mix of penicillin, streptomycin and other antibiotics during fermentation. This had NO effect. My conclusion was that the so-called fermentation is primarily an enzymatic process using amylases and pectinases contained in the coffee pulp. Further to this point, we recently had reason to analyse coffee pulp which had been sun-dried on a patio. the result was ; "Yeast/mold, total plate count and coliform were all very low." Thus, for us, fermentation is not an issue in normal coffee processing. On the other hand, I have seen de-pulped coffee sit in a mound on a patio for a week, unable to be dried due to rain. After 10 days it can be smelled from 50 meters and is clearly rotting. I would guess that that is true fermentation and an awful sight to a coffee grower. For some years we also were interested in whether fermentation or enzymes. Several years ago, to test the notion, we checked temperature change during ‘fermentation’ and there was NO significant change. Next we tried adding a mix of penicillin, streptomycin and other antibiotics during fermentation. This had NO effect. My conclusion was that the so-called fermentation is primarily an enzymatic process using amylases and pectinases contained in the coffee pulp. Further to this point, we recently had reason to analyse coffee pulp which had been sun-dried on a patio. the result was ; “Yeast/mold, total plate count and coliform were all very low.”
Thus, for us, fermentation is not an issue in normal coffee processing.

On the other hand, I have seen de-pulped coffee sit in a mound on a patio for a week, unable to be dried due to rain. After 10 days it can be smelled from 50 meters and is clearly rotting. I would guess that that is true fermentation and an awful sight to a coffee grower.

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]]> By: thompson http://www.jimseven.com/2010/02/10/the-naturals-debate/#comment-98676 thompson Mon, 29 Mar 2010 21:07:07 +0000 http://www.jimseven.com/?p=1483#comment-98676 Excellent - thanks for the information and I would really like to see the whole document. If the enzymatic breakdown of pectins with the formation of pectic and other acids is not the main factor that transforms the mucilage into a soluble form, it would actually explain much. I read a bit more on this, and I was not aware what a key role micro-organisms play ... still I am just a little doubtful on the role of yeasts so would like to read more ... Tom Excellent – thanks for the information and I would really like to see the whole document. If the enzymatic breakdown of pectins with the formation of pectic and other acids is not the main factor that transforms the mucilage into a soluble form, it would actually explain much. I read a bit more on this, and I was not aware what a key role micro-organisms play … still I am just a little doubtful on the role of yeasts so would like to read more …
Tom

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]]> By: Peter G http://www.jimseven.com/2010/02/10/the-naturals-debate/#comment-98675 Peter G Mon, 29 Mar 2010 20:12:02 +0000 http://www.jimseven.com/?p=1483#comment-98675 Tom and James: I've wound up doing a lot of reading on the fermentation process in coffee over the years. I've come to believe that the idea that: "fermentation is a pectic reaction unrelated to microbial activity" is wrong. I realize it is the conventional wisdom, but I think it is a myth. First, check this paper out (here is the abstract, I will email you two the entire paper when I find it on my hard drive) http://www.asic-cafe.org/pdf/abstract/18_074.pdf. In this paper, Avellone et al show quite conclusively that pectin is unaffected all the way through mucilage detachment. In another experiment, they sterilized coffee mucilage and tried to dissolve it using pectolysis- it took over 3 days. Therefore, there must be another reason the mucilage dissolves. Avellone et al have gone on to prove in subsequent research (it's a pretty large body of work, check it out) that mucilage detachment is related to acidification, not pectolysis. In other words, bacteria (like lactic acid bacteria) and yeasts whose action produces acids are responsible for much of the physical activity of mucilage dissolution. The acids destroy the cell walls in certain cells in the mucilage, causing it to detach and dissolve. It's pretty clear in the studies that what is taught in the old books- that coffee fermentation is achieved by "soft-rot" enzymes already present in the coffee pulp- is incorrect, and that in fact it is the microorganisms like bacteria and yeasts that actually make the mucilage dissolve. Also, there is no question that many yeasts and flavor-producing bacteria (like acetobacter and lactobacillus) are very active in coffee fermentation. There are many studies that list these in detail. Some seem to show that the lactic acid bacteria are the most important both in terms of mucilage removal and flavor. There is no question that there is abundant microbial activity in the fermentation tank, that this activity produces various compounds, and these compounds have flavor. best, Peter G Tom and James:

I’ve wound up doing a lot of reading on the fermentation process in coffee over the years. I’ve come to believe that the idea that: “fermentation is a pectic reaction unrelated to microbial activity” is wrong. I realize it is the conventional wisdom, but I think it is a myth.

First, check this paper out (here is the abstract, I will email you two the entire paper when I find it on my hard drive) http://www.asic-cafe.org/pdf/abstract/18_074.pdf. In this paper, Avellone et al show quite conclusively that pectin is unaffected all the way through mucilage detachment. In another experiment, they sterilized coffee mucilage and tried to dissolve it using pectolysis- it took over 3 days. Therefore, there must be another reason the mucilage dissolves.

Avellone et al have gone on to prove in subsequent research (it’s a pretty large body of work, check it out) that mucilage detachment is related to acidification, not pectolysis. In other words, bacteria (like lactic acid bacteria) and yeasts whose action produces acids are responsible for much of the physical activity of mucilage dissolution. The acids destroy the cell walls in certain cells in the mucilage, causing it to detach and dissolve. It’s pretty clear in the studies that what is taught in the old books- that coffee fermentation is achieved by “soft-rot” enzymes already present in the coffee pulp- is incorrect, and that in fact it is the microorganisms like bacteria and yeasts that actually make the mucilage dissolve.

Also, there is no question that many yeasts and flavor-producing bacteria (like acetobacter and lactobacillus) are very active in coffee fermentation. There are many studies that list these in detail. Some seem to show that the lactic acid bacteria are the most important both in terms of mucilage removal and flavor. There is no question that there is abundant microbial activity in the fermentation tank, that this activity produces various compounds, and these compounds have flavor.

best,

Peter G

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]]> By: James Hoffmann http://www.jimseven.com/2010/02/10/the-naturals-debate/#comment-98663 James Hoffmann Thu, 25 Mar 2010 21:17:02 +0000 http://www.jimseven.com/?p=1483#comment-98663 As far as I understand what is going on in the fermentation tank - there is a lot of pectin breaking down through hydrolysis. I read about experiments where they added pectinase to speed up the process but that didn't produce the same results in a shorter period of time. Yeast activity (in the little I've read) has been pretty minimal, though there is a sharp change in pH around the time a coffee ought to be pulled out of the tank but I can't remember what caused it. (sorry) As far as I understand what is going on in the fermentation tank – there is a lot of pectin breaking down through hydrolysis. I read about experiments where they added pectinase to speed up the process but that didn’t produce the same results in a shorter period of time.

Yeast activity (in the little I’ve read) has been pretty minimal, though there is a sharp change in pH around the time a coffee ought to be pulled out of the tank but I can’t remember what caused it. (sorry)

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]]> By: thompson http://www.jimseven.com/2010/02/10/the-naturals-debate/#comment-98662 thompson Thu, 25 Mar 2010 21:12:22 +0000 http://www.jimseven.com/?p=1483#comment-98662 It's just been sticking in my mind since reading it weeks ago ... but what does yeast have to do with coffee fermentation? You can have yeast fermentation I suppose but it would take too long to develop to be significant in terms of an influence on the final product. Correct me please if I am wrong but coffee fermentation is an enzymatic reaction, enzymes present already within the coffee mucilage. No foreign agents required for fermentation It’s just been sticking in my mind since reading it weeks ago … but what does yeast have to do with coffee fermentation? You can have yeast fermentation I suppose but it would take too long to develop to be significant in terms of an influence on the final product. Correct me please if I am wrong but coffee fermentation is an enzymatic reaction, enzymes present already within the coffee mucilage. No foreign agents required for fermentation

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]]> By: samuli marila http://www.jimseven.com/2010/02/10/the-naturals-debate/#comment-98659 samuli marila Thu, 25 Mar 2010 10:53:36 +0000 http://www.jimseven.com/?p=1483#comment-98659 this comment by GW is so important that it deserves to be highlighted. it is valid for the world wide agricultural situation, mono-culture and money-crops at an all to high prize in the long run... "...whether coffee should be grown at all in most places where it is currently planted. It is, after all, not a food crop and offers no real nutritional value. There are other things that could be grown in most producing countries that would make more sense in the long run..." this deserves its own thread, perhaps in another more general agricultural forum. this comment by GW is so important that it deserves to be highlighted. it is valid for the world wide agricultural situation, mono-culture and money-crops at an all to high prize in the long run…
“…whether coffee should be grown at all in most places where it is currently planted. It is, after all, not a food crop and offers no real nutritional value. There are other things that could be grown in most producing countries that would make more sense in the long run…”
this deserves its own thread, perhaps in another more general agricultural forum.

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