Frequently Asked Questions
What is Innocork®?
Innocork® is a patented process that extracts TCA and other volatile organic compounds from cork. Surface-adsorbed TCA is removed by physical-chemical actions of temperature and solvent polarity of a carrier gas composed of water vapor and ethyl alcohol.
What is TCA?
TCA stands for 2,4,6-Trichloroanisole. TCA is a naturally occurring metabolite produced by several fungus species. TCA is detectable by the human nose in ng/L (nanograms per Liter), and poses no toxic effect at naturally occurring levels. Once formed, TCA is chemically stable and easily adsorbed by many natural and synthetic materials. TCA is pervasive in nature and industry and has been found in foods and beverages (e.g. coffee and cocoa beans, wine and beer, and bottled and municipal drinking water), packaging materials made of wood (including cork, paper and cardboard) and plastics.
How much TCA does Innocork remove from cork?
The amount of TCA that Innocork removes varies with the amount originally in the corks. Independent laboratory trials of natural cork samples processed with Innocork resulted in TCA extraction ranges from 60% to 85%.
What other quality assurance controls does Cork Supply have in place besides Innocork to prevent against TCA?
At Cork Supply, Innocork is just one step in our integrated company-wide quality assurance system. At every step from forest to bottle, we maintain 100% traceability, best manufacturing practices and internal quality control procedures. We also perform rigorous sensory and SPME-GC/MS (Solid Phase Micro Extraction – Gas Chromatography/Mass Spectrometry) testing of all corkwood and finished cork lots. Our releasable TCA acceptance threshold for all incoming corkwood and outgoing corks is a strict < 1.5 ng/L. Innocork, which has been independently validated to reduce TCA and other offer aromas in corks up to 85% and to improve sensory uniformity, is used on all quality assured natural cork lots. Finally, to be released for shipment from Portugal, all our natural cork lots must pass final QA inspection, testing and approval. Further quality control procedures and sensory and SPME-GC/MS testing is likewise conducted by regional Cork Supply cork finishing plants on every incoming and outgoing cork lot to ensure they remain in compliance with our strict quality specifications.
Will giving corks multiple Innocork treatments lower TCA levels further?
Yes. However, just one pass through the Innocork process reduces levels significantly. Quality gains from repeat treatments are not significant enough to be meaningful.
Does Innocork remove other volatile compounds from cork besides TCA?
Yes. Innocork removes many other unwanted aroma compounds, resulting in very neutral, predictable, uniform cork lots.
For which corks does Cork Supply use Innocork?
Cork Supply uses Innocork for all our natural corks, including: Alpha™, Natura™, Alpha B™ and Colmated corks.
Does Cork Supply use Innocork for 1+1 and other technical corks?
No. Innocork is used only for natural corks, not technical stoppers made from cork granules. Cork Supply uses Vapex®, a process using high-temperature steam, to volatize TCA from cork granules, and an identical steam distillation process for 1+1 discs.
Is Innocork safe for use on corks destined for wines?
Yes, Innocork is 100% safe for use on corks destined for wines. Innocork uses the same approved food-grade fermentation ethanol used by wineries.
Is Innocork safe for the environment?
Yes, Innocork is an environmentally safe and sustainable technology. The water vapor and ethanol exhaustion released into the atmosphere is ten times lower in Total Organic Compounds concentration than the legal admissible European limit. Moreover, Innocork achieves high efficiency using modest temperatures, requiring low energy consumption (less than 10% of the overall energy needed to manufacture natural cork closures).
Why does Innocork use ethyl alcohol?
Ethyl alcohol (also called ethanol and grain alcohol) is the agent in wine that causes TCA in a cork to be released into the wine. By using ethyl alcohol, Innocork mimics this chemical process prior to bottling and under conditions that prevent the undesired re-adsorption of TCA into the cork while preserving the desired functional qualities of natural cork.
Does the alcohol used in Innocork leave any aroma?
No. Ethyl alcohol is the same type of alcohol naturally produced in wine fermentation. Any residual ethanol from the Innocork process quickly evaporates.
If a winery receives corks with unacceptable levels of TCA from another supplier, can Cork Supply process them with Innocork to lower TCA to acceptable levels?
While possible, it would not likely be recommended, since it would require the winery to ship the corks to Cork Supply facilities in Portugal. Also, while Innocork is expected to have the same TCA-reducing impact on treated corks (that is, corks already treated with paraffin and silicon), Innocork has been fully tested on untreated corks, only.
Is the Innocork process patented?
Yes. Innocork received European Patent Publication Nº 1 444 075, titled "New Process for Treating Cork Stoppers or Planks for the Reduction of Strange Aromas, namely 2,4,6-Trichloroanisol.” Innocork is available exclusively from Cork Supply.
How long has Innocork been in development?
Cork Supply began independent research on methods to remove TCA from cork in 1998. Innocork has been undergoing test trials since 2001, and since 2003 at a pre-industrial scale level. The first commercial shipments were made in early 2005. Since January 2007, Cork Supply has treated all commercial natural corks with Innocork.
Have any long-term tests been conducted with wines sealed with corks that have been processed with Innocork?
Yes. Cork Supply has been conducting tests on Innocork sealed wines since 2002. Routine bottling trials have been underway since 2004, prior to initiating commercial deliveries to wineries.
Have any independent Innocork validation studies been done?
Yes. Several acclaimed independent research institutes have completed and/or are conducting ongoing Innocork trials and analysis to validate the efficacy of Innocork on bottled wine:
- ETS Labs (USA) – Tests performed in 2007 concluded with individual cork analysis. Additional 6-, 9- and 12-month bottling trials concluded in 2008. Reports available upon request.
- Australian Wine Research Institute (AWRI) (Australia) – Tests performed under a closure trial protocol since 2007. 6-, 12-, 18- and 24-month bottling trials concluded. Reports available upon request.
- Laboratoire Excel (France) – Tests preformed in 2007 concluded with individual cork analysis. Additional 14-month bottling trials concluded in 2008. Report available upon request.