International Society of Beverage Technologists

International Society of Beverage Technologists ISBT is the only organization whose sole interest is the technical and scientific aspects of soft drinks and beverages. With members from around the world, membership is open to any person engaged in the science, technology, or production of soft drinks or beverages, including those suppliers to the beverage […]

Monday, 28th November 2022

International Society of Beverage Technologists

ISBT is the only organization whose sole interest is the technical and scientific aspects of soft drinks and beverages. With members from around the world, membership is open to any person engaged in the science, technology, or production of soft drinks or beverages, including those suppliers to the beverage industry whose principal occupation is substantially technical in nature. This includes individuals employed by bottlers, franchise companies, packaging, flavor, ingredient, and equipment suppliers who are engaged in scientific or technical positions.

ISBT enhances the promotion, development, and dissemination of knowledge relating to the art and science of beverage technology for the non-alcoholic beverage industry. Focus areas of activity include (but are not limited to) beverage formulation, production, packaging, equipment, and distribution. We do this by:

Providing forums for scholarly discussion
Stimulating the application of science in the industry
Publishing voluntary technical guidelines and best practices
Encouraging and fostering research

Most of our activities center around our annual conference (BevTech), our regional events (Asia Pacific, Canada, Europe, India, and Latin America), and our 9 technical committees:

Beverage Gases
Beverage and Ingredient R&D
Beverage Operations & Processing
Packaging Technology
Quality
Retail Equipment and Fountain Technology
Sanitation and Microbiological Control
Sweetener
Water Quality & Treatment

ISBT also has a series of online microlessons designed to provide an important and easily available resource for our global community of beverage professionals. The Beverage Institute by ISBT® currently offers 9 courses covering everything from the Fundamentals of Beverage Technology to more specialized courses on Microbiology, Sweeteners, Gases, Water, and more. More information about these courses can be found at https://www.isbt.com/isbt-beverage-institute.asp.

Membership rates, benefits, and more can be found at https://www.isbt.com/membership.asp. KBI members can enter Kombucha in the Discount Code field to get $50 off your first year’s membership.

Comparison of Rare Combinations LLC’s Kombucha Alcohol Detector to GC-FID

108 Coronado Ct. Suite B Fort Collins, CO 80525 info@beyersanalytical.com (970) 226-8649 Introduction Rare Combinations LLC contracted Beyers Analytical Brewing Sciences (BABS) to provide an impartial and critical review of their Kombucha Alcohol Detector. BABS is an analytical laboratory based in Fort Collins, Colorado that is dedicated to developing and performing chemical and microbiological measurements […]

Monday, 15th June 2020

108 Coronado Ct.
Suite B
Fort Collins, CO 80525

info@beyersanalytical.com

(970) 226-8649

Introduction

Rare Combinations LLC contracted Beyers Analytical Brewing Sciences (BABS) to provide an impartial and critical review of their Kombucha Alcohol Detector. BABS is an analytical laboratory based in Fort Collins, Colorado that is dedicated to developing and performing chemical and microbiological measurements for kombucha and beer producers. The analysts at BABS are certified beer chemists with the Alcohol and Tobacco Tax and Trade Bureau (TTB) and are qualified to provide accurate measurements of components within beverage products. BABS provides education for kombucha producers regarding analytical techniques that can be used to monitor their products. The low level of ethanol required for non-alcoholic kombucha necessitates quick, affordable, and reliable testing that can be used to measure levels at or below 0.5% alcohol by volume (ABV).

Methodology

BABS compared the Rare Combinations LLC Kombucha Alcohol Detector (KAD) to gas chromatography paired with flame ionization detection (GC-FID) utilizing AOAC 2016.12. Standards were purchased from Cerilliant when applicable. Quality controls were made from grain alcohol and analytically proofed using a calibrated Anton-Paar DMA4500 densitometer that provides accurate density readings to five decimal places (± 0.00001). Five kombucha samples were purchased from a local grocery store and tested by GC-FID and KAD in duplicate to allow comparison. The KAD was operated according to instructions provided by Rare Combinations LLC. The ABV read-out and the raw value read‑out were recorded for each sample measured by the KAD. All sample measurements were performed in duplicate and occurred at room temperature (22-23~C).

Results

The KAD instrument interface provides sample measurement results reported as ABV from a factory-installed calibration curve as well as the ability to make a custom calibration curve using raw data from the detector’s response. We decided to evaluate the accuracy of the instrument using the factory-installed calibration curve as well as using its capability to generate a custom calibration curve for alcohol. The table below compares the results from GC-FID, the KAD factory-installed calibration curve, and the KAD custom calibration curve.

Table 1: Comparison of alcohol values determined by GC-FID and KAD

Sample	Measured ABV (%) (GC-FID)	Measured ABV (%) (KAD – Factory Curve)	Measured ABV (%) (KAD – Custom Curve)
Kombucha 1	0.35 ± 0.01	0.44 ± 0.05	0.32 ± 0.05
Kombucha 2	0.82 ± 0.01	0.79 ± 0.05	0.76 ± 0.05
Kombucha 3	0.60 ± 0.01	0.63 ± 0.05	0.54 ± 0.05
Kombucha 4	0.86 ± 0.01	0.78 ± 0.05	0.76 ± 0.05
Kombucha 5	0.16 ± 0.01	0.25 ± 0.05	0.14 ± 0.05
QC 0.75%	0.74 ± 0.01	0.68 ± 0.05	0.77 ± 0.05

Discussion

The KAD version that we used can provide comparable results to the GC-FID using either the factory-installed calibration curve or the custom calibration curve. However, we would recommend that each customer who purchases the KAD take the time to build their own calibration curve on site and determine what curve fit works best for them.

Final Recommendations

The KAD can be a powerful tool for spot-checking alcohol concentrations in day-to-day operations. Taking the time to develop an on-site, instrument-specific calibration curve for each KAD can potentially increase accuracy. Any instrument is only as good as the operator running it. Training, accurate standards, and quality control are required to achieve reliable measurements. Proximity to the threshold concentration of 0.5% is also an important consideration. Testing of final product with GC-FID using method AOAC 2016.12 is still recommended to ensure legal compliance.

Disclosure and Disclaimer

BABS received payment from Rare Combinations LLC to perform this instrument review and validation. Rare Combinations LLC wanted a completely impartial review and did not make payment contingent upon any specific or desired outcomes. BABS does not make any guarantees or promises to the efficacy of the KAD for individual users or the reproducibility or robustness of the instrument over time. The writing in this document is the result of a small‑scale study performed by BABS and is the opinion of BABS only. The data, opinions, observations, and anything of the like should not be used as legal guidance. Past performance is no guarantee of future results. The KAD cannot replace GC-FID as an absolute analytical method.

Food Safety Modernization Act (FSMA)

Tuesday, 5th November 2019

The Food Safety Modernization Act (FSMA), a sweeping food safety legislation amending the Food, Drug and Cosmetic Act of 1938, was enacted on January 4, 2011. It aims to ensure the United States food supply is safe by shifting the focus from responding to contamination to preventing it. As required by FSMA, the FDA implemented the HARPC (Hazard Analysis and Risk-Based Preventive Controls) regulation (also referred to as the “Preventive Controls Rule”) for the food industry on September 17, 2015. Compliance dates were extended for small and very small businesses:

September 18, 2017: Small businesses (with fewer than 500 full-time employees)

September 17, 2018: Very small businesses (businesses averaging less than $1 million per year (adjusted for inflation) in annual sales

HARPC is similar to HACCP (Hazard Analysis and Risk-Based Preventative Controls) which is mandatory for certain food categories such as seafood, juice, meat/poultry (USDA) but includes planning for potential terrorist acts or intentional adulteration requiring facility registration with the FDA, controls on transportation inbound/outbound, facility visitor access, etc.

HARPC requires virtually every food manufacturer, processer, packer, and storage facility to:

identify food safety and adulteration hazards associated with their foods and processes,
implement controls to minimize the hazards,
verify that the controls are working, and
design and implement corrective actions to address any deviations from the controls that might arise in a food safety plan.

Everything in a HARPC plan must be properly documented and must conform to FDA’s standards and definitions surrounding facilities, controls, hazards, and the adulteration of foods. HARPC requires each food facility to document all aspects of its plan, periodically review it, constantly maintain it, and document its verification steps.

HARPC represents a substantial new regulatory requirement with an unprecedented level of coverage for the industry that must be taken seriously. Companies must create their unique food safety plan compliant with HARPC, update it, and produce the documentation to FDA upon request or inspection.

Facility Registration

Domestic and foreign facilities that manufacture, process, pack, or hold food/beverages for human or animal consumption in the US are required to register with the FDA and renew every even-numbered year. Registration is easy and free. Follow the prompts at the link below to register your facility. Registered facilities may be subject to random inspections.

http://www.fda.gov/Food/GuidanceRegulation/FoodFacilityRegistration/ucm2006831.htm

Registration is not required for AP5 Kombucha products (aka Hard Kombucha) as the FDA does not regulate alcoholic beverages.

Current Good Manufacturing Practices (cGMP’s) – Preventative

Controls (Critical components of Step 2 in HARPC)

Plant and Grounds

Facility exterior

Shouldn’t harbor pests
- Grass/weed control
- No stored equipment within immediate parameter
Protected points of entry
- Sealed, self-closing doors
- Screened vents at all intakes
- Walls, roof, foundation must prevent entry of water and pests

Facility Interior

Walls, floors ceilings should be durable, impervious,smooth, cleanable, white or light-colored
Adequate floor drainage
Screened windows
Adequate lighting and shielded bulbs
Adequate ventilation
Proper waste containment and disposal
Handwashing stations with dispensable soap, single-use towels, direct connection to drain, waste receptacles, signage
Washrooms, lunchrooms should not open directly to processing areas; negative air pressure in washrooms
Plumbing must have backflow devices between potable water systems and sewage lines

Receiving and Storage

Transportation inbound – inspect truck and materials for damage or contamination, improper temperature controls
Ensure Certificate of Analysis (CoA) if required or conduct inspection/testing to verify ingredients and packaging meet specifications
Storage
- Insure ingredients, packaging materials, product in process, and finished product are properly stored to prevent contamination – proper temperatures, 18” from wall, 6” off floor
- Chemicals in isolated storage – properly labeled and accessible safety data sheets (SDS)

Equipment

Designed, constructed and installed to be accessible for adequate cleaning, sanitation, and maintenance
Product contact surfaces should be smooth, non-corrosive, food-grade, non-absorbent, non-toxic, and free from cracks, crevices, and pitting
Must have adequate drainage
Establish a preventable maintenance program

Personnel

Establish and implement training programs for all new employees;
- Provide refresher training
  - Personal Hygiene
  - Allergen Standard Operating Procedures (SOP’s)
  - Product and Material Safety
Maintain a personal hygiene policy and enforce
- Hair and beard restraints
- Clean clothing and footwear (closed-toe only)
- Eating, drinking, and smoking in designated areas only (includes gum)
- No jewelry, watches, earrings; no fingernail polish or artificial nails
- Proper handwashing practices and signage
Only authorized personnel on-site; visitors and contract employees to sign-in
Employee health
- Inform management of any communicable disease or potential for contamination
  - Diarrhea, vomiting or other gastrointestinal illness
  - Jaundice
  - Open, blistered or infected cuts, wounds, abrasions, or burns

Sanitation and Pest Control

Establish procedures for cleaning and sanitation of premises, production areas, equipment, and storage areas.
- Document procedures, chemicals used/usage levels, and maintain a log of pre-op, periodic, and post-op sanitation.
Interior pest control devices must not contain bait of any kind
Exterior pest control devices must be tamper-resistant, locked, labeled, and secured
Maintain
- List of chemicals and pesticides used (including SDS and copies of labels which includes usage/application rates)
- Schedules/frequency
- Usage log that lists when and where used, concentration, how it was applied and by whom
- Location map of devices
- Activity reports/records for findings and actions
- Corrective action records

Traceability and Recall Protocol

Traceability
- Maintain documented procedures to ensure all raw materials, product, and packaging materials can be traced to usage dae and/or lot identification
- Finished products should carry a “use by” or “best by” date and lot number (if multiple lots per code date)
Consumer Complaint Log
- Outlines how complaints are processed, evaluated and investigated
- Document customer name, contact information, current date, name of item, a description of the product safety and/or quality complaint, the purchase date of item and possible receipt
Recall Protocol
- Document what is to be done in the event product must be recalled from the distribution system and/or shelf
- This will allow tracing and accounting for all identified defective products in a quick and efficient manner; managing communications in the event of a recall, and assisting outside agencies by having a predetermined plan and information-gathering mechanisms

KBI will be providing checklists and templates for some of these documents – stay tuned for more resources available in the Member Forum

B Corp Certification Process Webinar

B Corp Certification Process Webinar Presented By Danny Metcalf – Director of Business Operations, Brew Dr. Kombucha Join KBI & Danny Metcalf on Sept 18th @ 1pm PST for a webinar to discuss the process of B Corp certification. Brew Dr Kombucha embarked on the B Corp journey over three years ago to cement the core […]

Tuesday, 3rd September 2019

B Corp Certification Process Webinar

Presented By Danny Metcalf – Director of Business Operations, Brew Dr. Kombucha

Join KBI & Danny Metcalf on Sept 18th @ 1pm PST for a webinar to discuss the process of B Corp certification. Brew Dr Kombucha embarked on the B Corp journey over three years ago to cement the core environmental/culture beliefs of Founder & CEO Matt Thomas.

Danny spearheaded the assessment process and implementation of policies to align with B Corp, leading to a successful certification in the fall of 2018. Since certification, Brew Doctor Kombucha has been actively working to ingrain B Corp into their day-to-day culture, operations, and belief edifice.

Does your brand aspire to cultivating change from within the corporate structure? Do these values align with your own? Then, we invite you to listen in and ask questions. FREE for KBI Members; $40 for non-members.

What is a Certified B Corporation?

“Certified B Corporations are businesses that meet the highest standards of verified social and environmental performance, public transparency, and legal accountability to balance profit and purpose. B Corps are accelerating a global culture shift to redefine success in business and build a more inclusive and sustainable economy.

Society’s most challenging problems cannot be solved by government and nonprofits alone. The B Corp community works toward reduced inequality, lower levels of poverty, a healthier environment, stronger communities, and the creation of more high quality jobs with dignity and purpose. By harnessing the power of business, B Corps use profits and growth as a means to a greater end: positive impact for their employees, communities, and the environment.

B Corps form a community of leaders and drive a global movement of people using business as a force for good. The values and aspirations of the B Corp community are embedded in the B Corp Declaration of Interdependence.”

About B Corps. Retrieved from https://bcorporation.net/about-b-corps

Details

DATE: Sept 18th, 2019

TIME: 1-2pm PST; 30 min presentation & 15 min Q&A

COST: Free for KBI members, $40 for non-members

REGISTRATION LINK

Have questions? Please send in advance to admin@kombuchabrewers.org

Not a KBI Member, JOIN TODAY

KBI Member Code of Ethics

Kombucha Brewers International (KBI) – Code of Ethics This code of ethics was proposed at the KKON 19 Standard of Identity session. Please review all of the items listed and then share your feedback here (must be logged in). “As KBI Members, we have a responsibility to the kombucha industry and, in particular, to our customers, […]

Tuesday, 7th May 2019

Kombucha Brewers International (KBI) – Code of Ethics

This code of ethics was proposed at the KKON 19 Standard of Identity session. Please review all of the items listed and then share your feedback here (must be logged in).

“As KBI Members, we have a responsibility to the kombucha industry and, in particular, to our customers, consumers, personnel and the association. We hereby agree to:

Maintain the highest standards of business conduct by using only legal and ethical means in all business activity.
Actively promote and encourage the highest level of integrity within the kombucha industry. Be fair, equitable and respectful to employees, associates, suppliers, competitors, customers, the public, and all business or professional relationships. Refrain from discriminatory practices in dealing with our employees, suppliers and customers.
Observe all applicable state, federal, foreign or international laws and regulations pertaining to the manufacturing, labeling, handling, importing, distributing, promoting and selling of kombucha and related products.
Provide a safe working environment.
Restrict employment to those ages/job positions mandated either by the requirements of the Fair Labor Standards Act, or state or local minimum employment ages; and, in the case of overseas facilities, to International Labor Organization standards.
Avoid knowingly dealing with those who use any forced labor or exploitative working conditions.
Respect the rights of others concerning their intellectual property and, if any innocent breach occurs, promptly address and rectify any such breach.
Comply with all laws concerning antitrust and agreements with competitors to: fix prices or other sales terms; divide or assign sales territories, customers or product lines; or coordinate bids and agreements with customers to fix their resale prices, and all laws that prohibit restraints of trade, predatory economic activities and unfair or unethical business practices.
Never pay any bribe, kickback or other corrupt payment in any form for the purpose of obtaining or retaining business or obtaining any other favorable action, nor offer or extend any gift or entertainment that is illegal, known to be in violation of the rules of the recipient’s organization, or likely to result in a feeling of expectation or obligation on the part of the recipient.
Comply in good faith with contractual obligations.
Never comment on a competitor’s product without a good faith basis or need for such statements. Never make false statements about competitors.
Support the Association by taking an active role in KBI activities. Cooperate in every reasonable and proper way with other Association Members and work with them toward the advancement of the kombucha industry.
Represent KBI, its positions, policies and fellow Members in a positive, constructive and professional manner.
Act in a manner consistent with, and make every effort to uphold this code of ethics. If a member considers that it is no longer able to comply with this Code of Ethics, that member must resign from the Association.

This Code of Ethics does not set forth all aspects of good conduct and ethical behavior. Acceptance of, and adherence to this Code is a condition of membership.”

Webinar Series: G3 “Beverage on Tap – What’s to Come”

G3: Beverage on Tap – What’s to Come DATE: 11/14/18; 1 pm PST on Zoom WHO: Scott Fore – Manager of G3’s Beer Sales Group COST: Free Members/ $20 Non-Members WEBINAR SUMMARY Join us for a webinar led by Scott Fore – Manager of G3’s Beer Sales Group to discuss the future of beverages on tap. This […]

Thursday, 25th October 2018

G3: Beverage on Tap – What’s to Come
DATE: 11/14/18; 1 pm PST on Zoom
WHO: Scott Fore – Manager of G3’s Beer Sales Group
COST: Free Members/ $20 Non-Members

WEBINAR SUMMARY

Join us for a webinar led by Scott Fore – Manager of G3’s Beer Sales Group to discuss the future of beverages on tap. This webinar will teach how putting your beverages on tap offers you lower up-front development costs, along with small-batch-to-large-batch production flexibility and higher margins in sales.

WEBINAR TAKEAWAYS

– Why are Beverages On Tap So Important to Your Business?

– What Beverages are Going on Tap?

– Who is pushing the On Tap Industry to Innovation?

– I have got this Beverage I want to put on tap. What do I need to know?

– Supply Chain – How It Works

– And much more!

REGISTER HERE!

ABOUT THE WEBINAR INSTRUCTOR

Scott Fore – Manager of G3’s Beer Sales Group

As manager of G3’s Beer Sales Group, Scott Fore manages a team of sales professionals that focus on the beer and specialty beverage market. His current role is to assist customers to expand their on-premise presence and explore export markets. He works closely with one- way petainerKegTM manufacturing and G3 teams to provide market education, filling training, technical services and logistics support so customers easily transition to this draught format. In addition to the keg, G3 offers integrated packaging solutions from crowns, corks and labels.

Scott has 24 years of deep knowledge and experiences in the beverages industry. He has worked in distribution, national accounts, category management, supply chain, import and export, production for domestic and international companies such as Southcorp Wines, Rocland Wine Group and 2X4 Brewing & Imports. He has developed distribution networks globally for wine and craft beer brands like Chocolate Box Wines, Ass Kisser Ales, Parallel 49 Brewing Company and Steamworks Brewing Company. Scott’s unique background ofsales, operations and production allows him to assess the viability of a beverage and its potential growth.

Webinar Series: Kombucha Standard of Identity

Kombucha Standard of Identity DATE: 9/26/18; 1 pm PST on Zoom WHO: Hannah Crum COST: Free/Members Only WEBINAR SUMMARY Join us for a free, members-only webinar to discuss the Kombucha Standard of Identity, led by KBI President, Hannah Crum. Before the webinar, please review the Kombucha Standard of Identity (draft version), located HERE in the […]

Sunday, 16th September 2018

Kombucha Standard of Identity
DATE: 9/26/18; 1 pm PST on Zoom
WHO: Hannah Crum
COST: Free/Members Only

WEBINAR SUMMARY

Join us for a free, members-only webinar to discuss the Kombucha Standard of Identity, led by KBI President, Hannah Crum.

Before the webinar, please review the Kombucha Standard of Identity (draft version), located HERE in the Member Forum. Since this is a members-only meeting, non-members will not be able to access the webinar or the Kombucha Standard of Identity.

WEBINAR TAKEAWAYS

– Definition of Kombucha

– Pasteurization

– Label Declaration

– And much more!

ABOUT THE WEBINAR INSTRUCTOR

Hannah Crum has taught Kombucha making classes to all size groups, from individuals to workshops of 100+, all over the country for over a decade, spreading the message of Kombucha and its bacterial benefits far and wide through a variety of venues including festivals, health conferences, podcasts, interviews, articles and more. Her how-to videos have piled up +100,000’s of views and Kombucha Kamp was featured on “What’s Brewing?” hosted by Jody Rudman on the Veria Network.

In addition to teaching, Hannah installs large-scale Kombucha set-ups and is the Master Brewer for numerous restaurants and shops in the Los Angeles area, as well as consult for many Kombucha brands from those just starting out to established breweries looking to scale up. In 2014, as an extension of their desire to “change the world, one gut at a time” while growing the Kombucha industry, Hannah and her partner, Alex, co-founded Kombucha Brewers International – a non-profit trade association dedicated to promoting and protecting commercial Kombucha around the world.

Webinar Series: Alcohol & Flavour Management in Kombucha Products

ALCOHOL & FLAVOUR MANAGEMENT IN KOMBUCHA PRODUCTS DATE: 1/16/2019 1 pm on Zoom WHO: Aubrey Dyer COST: Free (members); $20 (non-members) The presentation will discuss some of the challenges involved producing a beverage that is authentic, has great flavour and of course meets legal requirements on a commercial scale. The Flavourtech Spinning Cone Column will […]

Thursday, 6th September 2018

ALCOHOL & FLAVOUR MANAGEMENT IN KOMBUCHA PRODUCTS
DATE: 1/16/2019 1 pm on Zoom
WHO: Aubrey Dyer
COST: Free (members); $20 (non-members)

The presentation will discuss some of the challenges involved producing a beverage that is authentic, has great flavour and of course meets legal requirements on a commercial scale. The Flavourtech Spinning Cone Column will be explained in detail and some of the approaches taken to alcohol adjustment in the Beer and Wine industries discussed.

Presentation Topics

The Challenges and Constraints in Scaling Up: Some of the challenges involved in producing a beverage that is authentic, has great flavour and of course meets legal requirements on a commercial scale.
Introduction to the Spinning Cone Column (SCC): The Flavourtech Spinning Cone Column will be explained in detail and some of the approaches taken to alcohol adjustment in the Beer and Wine industries discussed.
Alternative processing options
SCC deployment options

Webinar Host

Aubrey Dyer spent 20 years in a range of technical and commercial roles in the New Zealand Food and Beverage industry before taking responsibility for the Americas Region for Flavourtech in early 2011. Since then he has worked closely with many premium food and beverage companies, assisting them to develop and produce market leading products with Flavourtech’s processing technologies.

About Flavourtech
Flavourtech has been in business for over 40 years with extensive expertise high-quality in flavour, alcohol, tea and coffee processing.

About Scan American Corporation
Scan American Corporation were founded in 1977 and specialize in distribution and support unique equipment from around the globe

Measuring Ethanol in Kombucha: Instrument Comparison Study

**The views and results in the following White Paper are the property of Beyers Analytical and do not necessarily reflect the opinions of Kombucha Brewers International.** Introduction Beyers Analytical Brewing Sciences, LLC (BABS) is an analytical laboratory based in Fort Collins, Colorado that is dedicated to performing chemical and microbiological measurements for kombucha, beer, spirits, […]

Tuesday, 7th August 2018

**The views and results in the following White Paper are the property of Beyers Analytical and do not necessarily reflect the opinions of Kombucha Brewers International.**

Introduction

Beyers Analytical Brewing Sciences, LLC (BABS) is an analytical laboratory based in Fort Collins, Colorado that is dedicated to performing chemical and microbiological measurements for kombucha, beer, spirits, wine, and coffee producers. The analysts at BABS are certified beer chemists with the Alcohol and Tobacco Tax and Trade Bureau (TTB) and are qualified to provide accurate measurements of components within beverage products. BABS provides education for kombucha producers regarding analytical techniques that can be used to monitor their products. We are often asked what methods can be used to monitor ethanol in kombucha.

The low level of ethanol required for non-alcoholic kombucha necessitates quick, affordable, and reliable testing that can be used to measure levels at or below 0.5% alcohol by volume (ABV). This study presents a comparison of four ethanol measurement technologies for the kombucha industry. Eight off-the-shelf kombucha products were analyzed in a blind test for ethanol content using gas chromatography (GC), an OptiEnz Sensors ethanol sensing system, an Anton-Paar Alcolyzer, and distillation paired with an Anton-Paar densitometer.

Results and Discussion

The table below presents the advantages and disadvantages of each ethanol measurement technology. These items are worth considering prior to using commercial laboratory testing or purchasing an instrument as part of a quality control program.

Average ethanol measurements for each kombucha sample and performance statistics for each technology are presented in the table below.

Gas Chromatography

Measurements of ethanol concentration made using GC were taken to be the target concentration for calculations of accuracy in this study due to the technology’s widespread use as a “gold standard.” However, high upfront costs, high maintenance costs, complicated procedures, and long measurement times prevent most kombucha producers from using this technology at their facilities.

OptiEnz Sensors Ethanol Sensing System

The OptiEnz Sensors ethanol sensing system is more affordable than GC and the Anton-Paar. Alcolyzer, is easier to use than GC, and has one of the shortest measurement times of these technologies. This technology provided ethanol measurements in kombucha that most closely matched GC measurements.

Anton-Paar Alcolyzer

The Anton-Paar Alcolyzer is the easiest technology to use, provides short measurement times, and is more affordable than GC. Ethanol measurements made with this technology were precise, but consistently lower than GC measurements.

Distillation and Anton-Paar Densitometer

Distillation has a low upfront cost, very long sample preparation times, and requires higher-level technical training. Ethanol measurements made with this technology were consistently lower than GC measurements.

Conclusions

All the tested technologies are capable of measuring ethanol at concentrations found in kombucha, but the advantages and disadvantages of each method need to be considered when implementing a testing program. Proximity to the threshold concentration of 0.5% is also an important consideration. Any instrument is only as good as the operator running it. Training, accurate standards, and quality control are required to achieve reliable measurements.

Experimental Procedures

Gas Chromatography

Headspace gas chromatography – flame ionization detection (HS/GC-FID) measurements and sample preparation were performed using AOAC methods for determination of ethanol in kombucha (AOAC 2016.12). Analysis was completed on a HP 5890 Series II gas chromatograph (four measurements per sample) with a Restek Stabilwax-DA capillary column using nitrogen as the carrier gas, and resolution of methanol, ethanol, isopropanol, 1-propanol, and acetone was possible using this setup. A calibration curve was constructed using Cerilliant ethanol standards purchased from Sigma-Aldrich.

OptiEnz Sensors Ethanol Sensing System

Ethanol measurements were performed using an OptiEnz Sensors ethanol sensing system. The instrument was calibrated over 10 minutes using prepared ethanol standards. Ethanol measurements (six measurements per sample) were made by diluting 0.1 mL of sample into 50 mL of buffer, immersing the sensor probe into the dilute solution and allowing the system to stabilize for three minutes.

Anton-Paar Alcolyzer

Density and Alcolyzer measurements were performed using an Anton-Paar DMA 4500 M-EC with Enhanced Calibration for Ethanol paired with an Alcolyzer Beer ME module and Sample Handling Unit (Xsample 22). The instrument was calibrated with degassed, deionized water and achieved a density measurement of 0.99820 ± 0.00001 g/mL at 20ºC. Sample analysis (six measurements per sample) was performed by pumping 40 mL of sample through the system, bringing the sample temperature to 20.00 ± 0.01°C, and then collecting density and Alcolyzer measurements.

Distillation and Anton-Paar Densitometer

Kombucha samples (100 mL per sample) were distilled according to the TTB-recommended distillation-specific gravity method (AOAC 935.21). Density measurements (one measurement per sample) were made using the Anton-Paar densitometer.

Draft Kombucha Spec Sheet

What is Kombucha? Kombucha is fermented tea! Just like yogurt is fermented milk and sauerkraut is fermented cabbage, Though the Kombucha commercial industry is new, the drink is much older as it has been consumed for hundreds of years in every country on the planet. Kombucha Ingredients Tea [Camelia sinensis], Sugar [sucrose], SCOBY [fermentation culture], […]

Friday, 29th June 2018

What is Kombucha?

Kombucha is fermented tea! Just like yogurt is fermented milk and sauerkraut is fermented cabbage, Though the Kombucha commercial industry is new, the drink is much older as it has been consumed for hundreds of years in every country on the planet.

Kombucha Ingredients

Tea [Camelia sinensis], Sugar [sucrose], SCOBY [fermentation culture], flavorings [juice, fruit, herbs, etc]

Kombucha Chemical Characteristics

pH = 2.5-3.8

Acetic acid ferment: ~1%

By comparison, vinegar is diluted to 4-8% acetic acid

ABV = 0-2% for traditional, non-alcoholic ferments

ABV = 4-8% for Kombucha beer or high alcohol Kombucha hybrid ferments

Materials Acceptable for Use with Kombucha

Stainless Steel 304 & 316, 1

Neoprene Vinyl

1 British Stainless Steel Association – 304 types are used for most applications, including handling and storage.

Draft Kombucha Components

In a draft Kombucha set up, here are the components that come into contact with product.

Keg Coupler – Probe – 304 Stainless Steel
Product Washer, between the metal contacts of Tailpiece and Coupler – Neoprene
Product line Tailpiece for Coupler connection – 304 Stainless Steel
Product line – Vinyl
Tower Shank – 304 Stainless Steel
Faucet – 304 Stainless Steel

Antimicrobial Properties of Kombucha

Kombucha is naturally antimicrobial. It’s low pH and mix of organic acids have been shown to kill known pathogens on contact.

The antimicrobial activity of Kombucha was investigated against a number of pathogenic microorganisms. According to the literature on Kombucha, acetic acid is considered to be responsible for the inhibitory effect toward a number of microbes tested, and this is also valid in the present study. However, in this study, Kombucha proved to exert antimicrobial activities against E. coli, Sh. sonnei, Sal. typhimurium, Sal. enteritidis, and Cm. jejuni, even at neutral pH and after thermal denaturation. This finding suggests the presence of antimicrobial compounds other than acetic acid and large proteins in Kombucha. 2, 3, 4

Pathogens Sensitive to Kombucha

Staphylococcus aureus
Shigella sonnei
Escherichia coli
Aeromonashydrophila
Yersinia enterolitica
Pseudomonas aeruginosa
Enterobactercloacae
Staphylococcus epidermis
Campylobacter jejuni
Salmonella enteritidis
Salmonella typhimurium
Bacillus cereus
Listeria monocytogenes
Helicobacter pylori

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2 Sreeramulu, Guttapadu, Yang Zhu, and Wieger Knol. “Kombucha fermentation and its antimicrobial activity.” Journal of agricultural and food chemistry 48.6 (2000): 2589-2594.

3 Sreeramulu, G., Y. Zhu, and W. Knol. “Characterization of antimicrobial activity in Kombucha fermentation.” Acta Biotechnologica 21.1 (2001): 49-56.

4 Cetojevic-Simin, D. D., et al. “Antiproliferative and antimicrobial activity of traditional Kombucha and Satureja montana L. Kombucha.” J BUON 13.3 (2008): 395-401.