New research finds compounds which cause fruit flavours in fermented coffee – what could this mean?
Image Credit- 2BW0T4D Making pour-over coffee with a hario V60 dripper

New research finds compounds which cause fruit flavours in fermented coffee – what could this mean?

For some years now, experimental processing techniques have been a hot topic in the specialty coffee sector. These processing methods tend to result in more complex and unique sensory profiles, which also have more fruity flavours. In turn, they are becoming more and more popular among coffee professionals and enthusiasts alike.

Fermentation in processing plays a key role to create these fruitier flavours. However, up until recently, little was known about how this happens.

Last month, Zurich University of Applied Sciences’ (ZHAW) Coffee Excellence Centre presented its study on fermented coffee flavours at the American Chemical Society Spring 2023 meeting. As part of its findings, ZHAW identified three chemical compounds which directly contribute to fruity flavours and aromas in fermented coffee.

Naturally, this raises a lot of questions. But one of the more prominent is how might this research influence coffee processing methods in the coming years?
WHY DOES FERMENTATION MAKE COFFEE TASTE MORE FRUITY?
As the specialty coffee market has grown and diversified over the past few years, so have processing methods, too. Recently, more and more farmers have started using controlled fermentation to enhance coffee quality and flavour.

Generally speaking, this is done in two main ways. These are anaerobic or aerobic fermentation (which are different due to the absence or presence of oxygen). The removal of or presence of oxygen triggers several chemical reactions which create various acids and alcohols.

As a result, the sugars in the fruit of the coffee will break down over a prolonged period of time. This means the coffee will taste much sweeter and more complex, with more fruity and “winey” aromas and flavours.

We know that using particular yeasts and strains of bacteria during coffee fermentation can create specific sensory profiles. However, so far, there has been a somewhat limited understanding of which particular chemical compounds are responsible for creating certain flavours and aromas.

Looking at different processing methods
In its recent research, ZHAW outlined how it identified three distinct chemical compounds which create “the intense fruity flavour and the raspberry scent of a fermented coffee”.

Sasa Sestic is the founder and CEO of Project Origin in Australia, which helped to fund the research project. He also provided the coffee for the study: a green tip Gesha from Iris Estate in Panama, which Sasa co-owns with Jamison Savage.

“If we can understand how volatile compounds are formed at farm level, then we can understand how to highlight them through processing methods,” he says. “We unlock the potential to emphasise terroir with the support of science.”

A team led by Dr. Chahan Yeretzian, Head of the Coffee Excellence Centre, and Dr. Samo Smrke, Head of Coffee Transformation at the Coffee Excellence Centre, sorted the coffee into three different categories. These were according to processing method:

Washed processing (producers remove all flesh and mucilage from the beans before drying)
Pulped natural carbonic maceration processing (producers remove skin of the fruit while pulp is left intact)
Natural carbonic maceration
Similar to processes used in wine making, carbonic maceration has become more prominent in specialty coffee. For example, Sasa used a carbonic macerated Sudan Rume variety in his winning 2015 World Barista Championship routine.

The process involves placing cherries in sealed tanks and flushing them with carbon dioxide to remove any residual oxygen. Like other fermentation processing methods, carbonic maceration often results in more bright, wine-like, and fruity flavours.
Analysing different coffees
As part of the study, each coffee was brewed the same way. In order to analyse the aroma of all samples, ZHAW used a process known as gas chromatography-olfactometry (GC-O).

This is when scientists uses a gas chromatograph to separate individual components of a mixture or substance. They then pass through a mass spectrometer to identify each individual component.

Following this, human assessors were then asked to describe any aromas they could pick up on.

Chahan and Samo explain why this type of analysis was also used in conjunction with gas chromatography.

“We saw descriptors, such as ‘extremely sweet’, ‘crazy like strawberry’, and ‘artificially sweet’,” they say. “All the panellists were able to point out this characteristic in the carbonic macerated coffee.

“However, when examining the mass spectrometry data of the same coffee, at the exact same time and position in the chromatogram as panellists detected this unique and strong aroma, we were not able to detect compounds that could be attributed to those flavours,” they add.

“This confirms what flavour scientists have known since long: our nose outperforms even the best instrument on some of these low-threshold aro

ma active compounds that are so important to our understanding of the flavours we perceive,” Chahan and Samo continue.
COULD RESEARCH INFLUENCE MORE PRODUCERS TO STANDARDISE PROCESSING TECHNIQUES?
The results of ZHAW’s study concluded that six chemical compounds are responsible for fruity aromas and flavours in fermented coffee. However, the researchers stated that they were only able to identify three of them:

2-methylpropanal
3-methylbutanal
Ethyl 3-methylbutanoate
“One very intense fruity smelling compound, ethyl 3-methylbutanoate, stood out in the natural carbonic macerated coffee,” Chahan and Samo say. “It was found to be 125-times more abundant than in the washed coffee.”

It’s important to note scientists involved in the study emphasise that further research is necessary to identify the other three compounds. Moreover, we also need to know how these compounds are formed in the first place.

Farmers have been using particular yeasts, bacteria, and microorganisms during processing to control and enhance coffee flavour for some time now. But at the same time, this is clear evidence that specific chemical compounds result in the more characteristic fruity flavours we associate with experimentally processed coffees.

Ultimately, this leads us to several important questions. Arguably, however, the most important is if we know which compounds cause certain flavours, what does this mean for farmers?

Could producers develop and use more standardised processing methods? And would this be especially apparent with processing methods that result in more targeted and specific flavour profiles?

A question of value addition
Once producers know which specific compounds cause certain flavours, they can potentially process coffee with more intent and control. In turn, they can target particular sensory profiles. Eventually, this could lead to producing experimentally processed coffee on a larger scale – potentially allowing producers to add more value to their coffee.

“We first need to know how much potential a coffee has in the first place, in terms of flavour profile and volatile compounds,” Sasa says. “Then, through processing, we can determine how the amount of more desirable volatile compounds can be increased, so we can experience new flavours and aromas.”

Chahan and Samo agree, saying: “The practical implication of our study is that it provides farmers with new ways to improve the quality and quantity of fruity notes through post-harvest processing.

“This may eventually also help producers in a fast-growing market of fermented coffee to take more informed positions, as allegations on coffees ‘infused’ with fruit are surfacing,” they add.

The other side of the coin
However, with this in mind, we also need to acknowledge that not all coffee farmers have the ability to try fermentation and other experimental processing methods. These processing techniques often require significant upfront investment and specialist equipment which some producers may not have access to.

Moreover, for many smallholder farmers, the risks of such experimental processing methods may outweigh the benefits. Although these coffees can sometimes result in higher prices, they are typically more expensive to produce than more “traditional” processed coffees.

Similarly, without proper quality control protocols in place, producers may end up creating less desirable sensory profiles of fermented coffee – such as sour, overly fermented, or rancid flavours.
Although experimentally processed coffees are certainly becoming more popular, they only represent a fraction of the wider coffee market.

However, that’s not to say that research like this doesn’t benefit farmers who produce these kinds of coffees. In fact, with further studies conducted in the future, it could be possible to create more “accessible” experimental processing methods – just as long as farmers have access to the right infrastructure and support.

Spread the love
Posted in :

Latest Posts

We use cookies to personalise content and ads, to provide social media features and to analyse our traffic. We also share information about your use of our site with our social media, advertising and analytics partners. View more
Cookies settings
Accept
Privacy & Cookie policy
Privacy & Cookies policy
Cookies list
Cookie name Active
[:ar]Privacy Policy for qahwa world At qahwaworld, accessible from qahwaworld.com, one of our main priorities is the privacy of our visitors. This Privacy Policy document contains types of information that is collected and recorded by qahwaworld and how we use it. If you have additional questions or require more information about our Privacy Policy, do not hesitate to contact us. This Privacy Policy applies only to our online activities and is valid for visitors to our website with regards to the information that they shared and/or collect in qahwaworld. This policy is not applicable to any information collected offline or via channels other than this website. Our Privacy Policy was created with the help of the Free Privacy Policy Generator. Consent By using our website, you hereby consent to our Privacy Policy and agree to its terms. Information we collect The personal information that you are asked to provide, and the reasons why you are asked to provide it, will be made clear to you at the point we ask you to provide your personal information. If you contact us directly, we may receive additional information about you such as your name, email address, phone number, the contents of the message and/or attachments you may send us, and any other information you may choose to provide. When you register for an Account, we may ask for your contact information, including items such as name, company name, address, email address, and telephone number. How we use your information We use the information we collect in various ways, including to: Provide, operate, and maintain our website Improve, personalize, and expand our website Understand and analyze how you use our website Develop new products, services, features, and functionality Communicate with you, either directly or through one of our partners, including for customer service, to provide you with updates and other information relating to the website, and for marketing and promotional purposes Send you emails Find and prevent fraud Log Files qahwaworld follows a standard procedure of using log files. These files log visitors when they visit websites. All hosting companies do this and a part of hosting services' analytics. The information collected by log files include internet protocol (IP) addresses, browser type, Internet Service Provider (ISP), date and time stamp, referring/exit pages, and possibly the number of clicks. These are not linked to any information that is personally identifiable. The purpose of the information is for analyzing trends, administering the site, tracking users' movement on the website, and gathering demographic information. Cookies and Web Beacons Like any other website, qahwaworld uses 'cookies'. These cookies are used to store information including visitors' preferences, and the pages on the website that the visitor accessed or visited. The information is used to optimize the users' experience by customizing our web page content based on visitors' browser type and/or other information. For more general information on cookies, please read the Cookies article on Generate Privacy Policy website. Google DoubleClick DART Cookie Google is one of a third-party vendor on our site. It also uses cookies, known as DART cookies, to serve ads to our site visitors based upon their visit to www.website.com and other sites on the internet. However, visitors may choose to decline the use of DART cookies by visiting the Google ad and content network Privacy Policy at the following URL – https://policies.google.com/technologies/ads Our Advertising Partners Some of advertisers on our site may use cookies and web beacons. Our advertising partners are listed below. Each of our advertising partners has their own Privacy Policy for their policies on user data. For easier access, we hyperlinked to their Privacy Policies below. Google https://policies.google.com/technologies/ads Advertising Partners Privacy Policies You may consult this list to find the Privacy Policy for each of the advertising partners of qahwaworld. Third-party ad servers or ad networks uses technologies like cookies, JavaScript, or Web Beacons that are used in their respective advertisements and links that appear on qahwaworld, which are sent directly to users' browser. They automatically receive your IP address when this occurs. These technologies are used to measure the effectiveness of their advertising campaigns and/or to personalize the advertising content that you see on websites that you visit. Note that qahwaworld has no access to or control over these cookies that are used by third-party advertisers. Third Party Privacy Policies qahwaworld's Privacy Policy does not apply to other advertisers or websites. Thus, we are advising you to consult the respective Privacy Policies of these third-party ad servers for more detailed information. It may include their practices and instructions about how to opt-out of certain options. You can choose to disable cookies through your individual browser options. To know more detailed information about cookie management with specific web browsers, it can be found at the browsers' respective websites. CCPA Privacy Rights (Do Not Sell My Personal Information) Under the CCPA, among other rights, California consumers have the right to: Request that a business that collects a consumer's personal data disclose the categories and specific pieces of personal data that a business has collected about consumers. Request that a business delete any personal data about the consumer that a business has collected. Request that a business that sells a consumer's personal data, not sell the consumer's personal data. If you make a request, we have one month to respond to you. If you would like to exercise any of these rights, please contact us. GDPR Data Protection Rights We would like to make sure you are fully aware of all of your data protection rights. Every user is entitled to the following: The right to access – You have the right to request copies of your personal data. We may charge you a small fee for this service. The right to rectification – You have the right to request that we correct any information you believe is inaccurate. You also have the right to request that we complete the information you believe is incomplete. The right to erasure – You have the right to request that we erase your personal data, under certain conditions. The right to restrict processing – You have the right to request that we restrict the processing of your personal data, under certain conditions. The right to object to processing – You have the right to object to our processing of your personal data, under certain conditions. The right to data portability – You have the right to request that we transfer the data that we have collected to another organization, or directly to you, under certain conditions. If you make a request, we have one month to respond to you. If you would like to exercise any of these rights, please contact us. Children's Information Another part of our priority is adding protection for children while using the internet. We encourage parents and guardians to observe, participate in, and/or monitor and guide their online activity. qahwaworld does not knowingly collect any Personal Identifiable Information from children under the age of 13. If you think that your child provided this kind of information on our website, we strongly encourage you to contact us immediately and we will do our best efforts to promptly remove such information from our records.[:en]

Privacy Policy for Qahwa World

At Qahwa World, accessible from https://qahwaworld.com, one of our main priorities is the privacy of our visitors. This Privacy Policy document contains types of information that is collected and recorded by Qahwa World and how we use it. If you have additional questions or require more information about our Privacy Policy, do not hesitate to contact us. This Privacy Policy applies only to our online activities and is valid for visitors to our website with regards to the information that they shared and/or collect in Qahwa World. This policy is not applicable to any information collected offline or via channels other than this website. Our Privacy Policy was created with the help of the Free Privacy Policy Generator.

Consent

By using our website, you hereby consent to our Privacy Policy and agree to its terms.

Information we collect

The personal information that you are asked to provide, and the reasons why you are asked to provide it, will be made clear to you at the point we ask you to provide your personal information. If you contact us directly, we may receive additional information about you such as your name, email address, phone number, the contents of the message and/or attachments you may send us, and any other information you may choose to provide. When you register for an Account, we may ask for your contact information, including items such as name, company name, address, email address, and telephone number.

How we use your information

We use the information we collect in various ways, including to:
  • Provide, operate, and maintain our website
  • Improve, personalize, and expand our website
  • Understand and analyze how you use our website
  • Develop new products, services, features, and functionality
  • Communicate with you, either directly or through one of our partners, including for customer service, to provide you with updates and other information relating to the website, and for marketing and promotional purposes
  • Send you emails
  • Find and prevent fraud

Log Files

Qahwa World follows a standard procedure of using log files. These files log visitors when they visit websites. All hosting companies do this and a part of hosting services' analytics. The information collected by log files include internet protocol (IP) addresses, browser type, Internet Service Provider (ISP), date and time stamp, referring/exit pages, and possibly the number of clicks. These are not linked to any information that is personally identifiable. The purpose of the information is for analyzing trends, administering the site, tracking users' movement on the website, and gathering demographic information.

Cookies and Web Beacons

Like any other website, Qahwa World uses 'cookies'. These cookies are used to store information including visitors' preferences, and the pages on the website that the visitor accessed or visited. The information is used to optimize the users' experience by customizing our web page content based on visitors' browser type and/or other information. For more general information on cookies, please read the Cookies article on Generate Privacy Policy website.

Google DoubleClick DART Cookie

Google is one of a third-party vendor on our site. It also uses cookies, known as DART cookies, to serve ads to our site visitors based upon their visit to www.website.com and other sites on the internet. However, visitors may choose to decline the use of DART cookies by visiting the Google ad and content network Privacy Policy at the following URL – https://policies.google.com/technologies/ads

Our Advertising Partners

Some of advertisers on our site may use cookies and web beacons. Our advertising partners are listed below. Each of our advertising partners has their own Privacy Policy for their policies on user data. For easier access, we hyperlinked to their Privacy Policies below.

Advertising Partners Privacy Policies

You may consult this list to find the Privacy Policy for each of the advertising partners of Qahwa World. Third-party ad servers or ad networks uses technologies like cookies, JavaScript, or Web Beacons that are used in their respective advertisements and links that appear on Qahwa World, which are sent directly to users' browser. They automatically receive your IP address when this occurs. These technologies are used to measure the effectiveness of their advertising campaigns and/or to personalize the advertising content that you see on websites that you visit. Note that Qahwa World has no access to or control over these cookies that are used by third-party advertisers.

Third Party Privacy Policies

Qahwa World's Privacy Policy does not apply to other advertisers or websites. Thus, we are advising you to consult the respective Privacy Policies of these third-party ad servers for more detailed information. It may include their practices and instructions about how to opt-out of certain options. You can choose to disable cookies through your individual browser options. To know more detailed information about cookie management with specific web browsers, it can be found at the browsers' respective websites.

CCPA Privacy Rights (Do Not Sell My Personal Information)

Under the CCPA, among other rights, California consumers have the right to: Request that a business that collects a consumer's personal data disclose the categories and specific pieces of personal data that a business has collected about consumers. Request that a business delete any personal data about the consumer that a business has collected. Request that a business that sells a consumer's personal data, not sell the consumer's personal data. If you make a request, we have one month to respond to you. If you would like to exercise any of these rights, please contact us.

GDPR Data Protection Rights

We would like to make sure you are fully aware of all of your data protection rights. Every user is entitled to the following: The right to access – You have the right to request copies of your personal data. We may charge you a small fee for this service. The right to rectification – You have the right to request that we correct any information you believe is inaccurate. You also have the right to request that we complete the information you believe is incomplete. The right to erasure – You have the right to request that we erase your personal data, under certain conditions. The right to restrict processing – You have the right to request that we restrict the processing of your personal data, under certain conditions. The right to object to processing – You have the right to object to our processing of your personal data, under certain conditions. The right to data portability – You have the right to request that we transfer the data that we have collected to another organization, or directly to you, under certain conditions. If you make a request, we have one month to respond to you. If you would like to exercise any of these rights, please contact us.

Children's Information

Another part of our priority is adding protection for children while using the internet. We encourage parents and guardians to observe, participate in, and/or monitor and guide their online activity. Qahwa World does not knowingly collect any Personal Identifiable Information from children under the age of 13. If you think that your child provided this kind of information on our website, we strongly encourage you to contact us immediately and we will do our best efforts to promptly remove such information from our records.[:ru]Privacy Policy for qahwa world At qahwaworld, accessible from qahwaworld.com, one of our main priorities is the privacy of our visitors. This Privacy Policy document contains types of information that is collected and recorded by qahwaworld and how we use it. If you have additional questions or require more information about our Privacy Policy, do not hesitate to contact us. This Privacy Policy applies only to our online activities and is valid for visitors to our website with regards to the information that they shared and/or collect in qahwaworld. This policy is not applicable to any information collected offline or via channels other than this website. Our Privacy Policy was created with the help of the Free Privacy Policy Generator. Consent By using our website, you hereby consent to our Privacy Policy and agree to its terms. Information we collect The personal information that you are asked to provide, and the reasons why you are asked to provide it, will be made clear to you at the point we ask you to provide your personal information. If you contact us directly, we may receive additional information about you such as your name, email address, phone number, the contents of the message and/or attachments you may send us, and any other information you may choose to provide. When you register for an Account, we may ask for your contact information, including items such as name, company name, address, email address, and telephone number. How we use your information We use the information we collect in various ways, including to: Provide, operate, and maintain our website Improve, personalize, and expand our website Understand and analyze how you use our website Develop new products, services, features, and functionality Communicate with you, either directly or through one of our partners, including for customer service, to provide you with updates and other information relating to the website, and for marketing and promotional purposes Send you emails Find and prevent fraud Log Files qahwaworld follows a standard procedure of using log files. These files log visitors when they visit websites. All hosting companies do this and a part of hosting services' analytics. The information collected by log files include internet protocol (IP) addresses, browser type, Internet Service Provider (ISP), date and time stamp, referring/exit pages, and possibly the number of clicks. These are not linked to any information that is personally identifiable. The purpose of the information is for analyzing trends, administering the site, tracking users' movement on the website, and gathering demographic information. Cookies and Web Beacons Like any other website, qahwaworld uses 'cookies'. These cookies are used to store information including visitors' preferences, and the pages on the website that the visitor accessed or visited. The information is used to optimize the users' experience by customizing our web page content based on visitors' browser type and/or other information. For more general information on cookies, please read the Cookies article on Generate Privacy Policy website. Google DoubleClick DART Cookie Google is one of a third-party vendor on our site. It also uses cookies, known as DART cookies, to serve ads to our site visitors based upon their visit to www.website.com and other sites on the internet. However, visitors may choose to decline the use of DART cookies by visiting the Google ad and content network Privacy Policy at the following URL – https://policies.google.com/technologies/ads Our Advertising Partners Some of advertisers on our site may use cookies and web beacons. Our advertising partners are listed below. Each of our advertising partners has their own Privacy Policy for their policies on user data. For easier access, we hyperlinked to their Privacy Policies below. Google https://policies.google.com/technologies/ads Advertising Partners Privacy Policies You may consult this list to find the Privacy Policy for each of the advertising partners of qahwaworld. Third-party ad servers or ad networks uses technologies like cookies, JavaScript, or Web Beacons that are used in their respective advertisements and links that appear on qahwaworld, which are sent directly to users' browser. They automatically receive your IP address when this occurs. These technologies are used to measure the effectiveness of their advertising campaigns and/or to personalize the advertising content that you see on websites that you visit. Note that qahwaworld has no access to or control over these cookies that are used by third-party advertisers. Third Party Privacy Policies qahwaworld's Privacy Policy does not apply to other advertisers or websites. Thus, we are advising you to consult the respective Privacy Policies of these third-party ad servers for more detailed information. It may include their practices and instructions about how to opt-out of certain options. You can choose to disable cookies through your individual browser options. To know more detailed information about cookie management with specific web browsers, it can be found at the browsers' respective websites. CCPA Privacy Rights (Do Not Sell My Personal Information) Under the CCPA, among other rights, California consumers have the right to: Request that a business that collects a consumer's personal data disclose the categories and specific pieces of personal data that a business has collected about consumers. Request that a business delete any personal data about the consumer that a business has collected. Request that a business that sells a consumer's personal data, not sell the consumer's personal data. If you make a request, we have one month to respond to you. If you would like to exercise any of these rights, please contact us. GDPR Data Protection Rights We would like to make sure you are fully aware of all of your data protection rights. Every user is entitled to the following: The right to access – You have the right to request copies of your personal data. We may charge you a small fee for this service. The right to rectification – You have the right to request that we correct any information you believe is inaccurate. You also have the right to request that we complete the information you believe is incomplete. The right to erasure – You have the right to request that we erase your personal data, under certain conditions. The right to restrict processing – You have the right to request that we restrict the processing of your personal data, under certain conditions. The right to object to processing – You have the right to object to our processing of your personal data, under certain conditions. The right to data portability – You have the right to request that we transfer the data that we have collected to another organization, or directly to you, under certain conditions. If you make a request, we have one month to respond to you. If you would like to exercise any of these rights, please contact us. Children's Information Another part of our priority is adding protection for children while using the internet. We encourage parents and guardians to observe, participate in, and/or monitor and guide their online activity. qahwaworld does not knowingly collect any Personal Identifiable Information from children under the age of 13. If you think that your child provided this kind of information on our website, we strongly encourage you to contact us immediately and we will do our best efforts to promptly remove such information from our records.[:]
Save settings
Cookies settings