The mere chance of TCA contamination in new barrels has kept pressure on coopers to continue production methods that ensure total control and traceability.

The taint from TCA (2,4,6-trichloroanisole) and other haloanisoles such as TeCA and TBA, can contaminate wine as well as corks. While it is debatable how much of a risk barrels pose when it comes to contamination, winemakers commonly ask coopers: What do you do to ensure that risk is minimized?

“The cooperage industry has come a long way from 10 to 20 years ago,” said Chris Hansen, general manager at Seguin Moreau Napa Cooperage. Hansen said the company first certified its production process in 2004. “We’ve been doing this for quite some time,” he said.

TCA is an unseen threat, but Wines & Vines recently surveyed winemakers who said that additional concerns include blistering and other flaws. If wineries are paying top dollar (or euro) for quality barrels, they expect them to arrive in pristine condition.

Preventing taint through certified plans
To ensure barrels are free of contamination and flaws, many have developed a HACCP, or hazard analysis and critical control point plan. Such plans are used by a range of industries vulnerable to microbial contamination or companies looking to demonstrate a commitment to quality production. Coopers and other production companies also adhere to ISO 9001:2008 the international standard for quality production. Once these plans are in place, third-parties like Bureau Veritas certify that they are being followed.

Most high-quality barrels are marked with a bar code or number that the cooper or customer can use to trace the barrel from reception to production and even the source of the raw materials. “Really, traceability 15 years ago was the cooper’s memory,” said Mel Knox, who sells barrels by tonnelleries Taransaud and Francois Freres.

Bruno Remy is vice president and sales manager for Canton Cooperage, which has adhered to a certified HACCP plan since 2006. He said the chance of contamination means that the company needs to be ready to protect its products and its business as well. “We know it could be a problem, and when you know things are happening you need to be ready,” he said. “You can be implicated in the problem.”

Just as a high-end winery is going to want to protect its investment, Remy said the cooperage wants to protect itself from any claims contamination came from the barrels.

Both Canton and Seguin Moreau work with Bureau Veritas, a global firm based in Paris that was founded in 1828 to offer reports about the sea worthiness of commercial vessels. The huge company has offices across the globe and provides testing and certification in a variety of industries.

Tonnellerie Saury’s controls are certified through the Lloyds Register of Quality Assurance (LRQA.) The company states on its website that its production plants are certified to through a HACCP to ISO standards. Saury is part of the Groupe Charlois that includes barrel makers Berthomieu, Ermitage, Leroi and a cooperage in Cloverdale, Calif.

Since 2007, Groupe Charlois has employed its “Naturaleza” protocol developed by a French lab and describes it as similar to a HACCP process. The plan calls for testing its water supply, atmosphere and all incoming materials including machine lubricants, lighting, insulation and pallets. At a stave factory in the town of Varzy, France, the company claims workers weed the landscaping by hand to ensure pesticides don’t come near the wood supply area. Because the group has an integrated production chain from staves to finished goods, coopers like Saury say they have better control of quality.

Cooperages 1912 posts a HACCP plan, certificates of quality and lab results from haloanisoles testing online. The company’s HACCP plan applies to the Independent Stave Co. cooperage in Lebanon, Mo. (ISC is the parent company of Cooperages 1912.)

The plan, certified to comply with ISO standards, outlines basic steps to ensure the production areas are clean, well organized and that chemicals don’t come into contact with materials or finished products. It specifies that cleaning products not contain chlorine, and only food-grade lubricants are acceptable for equipment used on raw materials.

The plan dictates wood used for oak chips to come directly from the cooperage, and all bungholes are to be sealed with plastic bung caps or rubber bungs. Samples of all products used for “aging wine” are to be sent out at least quarterly for chemical analysis.

Cooperages 1912’s French staves and barrels come from Merraine International and Tonnellerie du France, which are certified to ISO standards by Bureau Veritas.

A July 2012 report by the lab Analytical Sciences found no haloanisoles or halophenols in Cooperages 1912’s wood materials or at levels lower than what’s permitted by the Federation Francaise de Tonnellerie, the trade group of French coopers.

That federation is still analyzing the accuracy of testing methods for the full range of haloanisoles and halophenols as well as contamination levels with the assistance of the International Bureau for Analytical Studies, BIPEA. According to a statement released through the federation’s spokeswoman Alice Dekker, the cooperage group and BIPEA are working with labs in every major wine region of the world. “It is not for our federation to rule on the merits of the different methods used by these laboratories, but to be able to build bridges or points of comparison between them.”

‘Complex’ logistics to ensure cleanliness
Seguin Moreau’s Hansen said most of the questions he receives about quality control come from winemakers and wineries comparing coopers when sourcing barrels. He said the company will conduct specific barrel-shaving tests, but that’s not too common. “Most people want to discuss our protocols to compare with other coopers they buy from,” he said.

Hansen added that Seguin Moreau tests all incoming wood for any type of contaminants. The water used in the aging yard is checked twice per year, and when the wood has finished seasoning, random samples are taken before the lots enter the cooperage, Hansen said. Inside the cooperage, Seguin Moreau analyzes its water, tests barrels for leaks and uses 15 different stations to check the air for traces of any contaminants. “Wood is a natural product, and I’m sure these safeguards are preventing a lot of issues,” Hansen said.

More and more coopers are establishing protocols to test for and prevent contamination, Remy said. “It has been a very important improvement in the wine industry to check these things and understand where it’s coming from.”

A couple of decades ago, Remy said, the view of a barrel was simple. Now it’s seen by the industry as a sensitive link in the supply chain for producing premium wine. All the testing and steps need to ensure traceability create what Remy called a “very complex system.”

Canton Cooperage is located in central Kentucky, though it is part of the Chene & Cie Group that also includes Tonnellerie Taransaud—one of the first coopers to apply stringent production controls to prevent TCA contamination.

Testing begins when the wood is received, through the seasoning process and at every stage of production. A run of barrels may require up to two or three lots of wood staves, and each lot needs testing. “You need to check from the beginning all the lots you use for the staves.”

If a stave lot tests clean, and part of it is used for barrel production and the rest is returned to storage, Remy said the rest of the lot will need to be retested before it’s used for barrels.

But it’s not just the wood. Remy said all the silicon bungs used to seal bungholes for shipment must be checked as well as the factory that makes the bungs. Packaging materials also need to be checked. If a clean barrel is wrapped in tainted cardboard, “that stuff is going to give you full contamination.”

The warehouse where the barrels are stored for shipment also requires regular testing, and when it’s time to ship, the containers must undergo analysis. Remy said that when the company receives containers it will run tests and wait a few days to ensure they’re clean before sending barrels out to customers. “For us it’s a detail, but we never use wooden pallets for transports that we get on the market. We are using pallets we make with our own wood.”

Every day, Remy said, Canton ships out samples to a lab in Cognac, France, for testing. The cooperage spends about $60,000 per year just for lab analysis, and the testing adds another layer of logistical planning. It’s not enough that the materials, staff and equipment are in place; everything needs to be clean.

Remy said contamination can be a matter of nanograms brought in from almost anywhere, and the possibilities start to pile up from employees bringing in contaminants on their clothes or crop dusters dropping pesticides from the air. “You need to be careful about what you’re doing,” Remy said.

Gary Chappell is the international manager for Bouchard Cooperages, which includes tonnelleries Billon, Cadus, Damy Vicard and the Canadell line of barrel alternatives. He said all of the cooperages regularly test for haloanisoles throughout the production process as part of their quality-control procedures. “This includes regular testing of wood lots when received, testing of staves in the stave yard during the seasoning process, atmospheric testing of the entire facilities and regular testing of all water used in each facility,” he said in an email. “Haloanisole testing on finished barrels and containers is available at an additional cost.”

The testing and analysis is based on the French cooper federation’s guide to good production processes. This guide outlines establishing a HACCP plan, testing and sampling regimen as well as maximum levels of TCA and other contaminants. The federation specifies in its guide that it is just making recommendations; each company is left to set its own standards.

Physical inspections
Blisters are one of the top complaints about barrel quality. During toasting, moisture trapped inside staves can explode, causing cracks and blisters. If the blisters are undetected and the barrels are filled with wine, the blisters can collect wine and lees and pose a contamination risk.

“Every single barrel is inspected, and we know that for the American market blisters are unacceptable,” Hansen said. He noted that during a tour of Burgundy he ran into a few winemakers who said if their strong or medium toasted barrels did not have blisters they doubted whether the barrel had been properly toasted. Hansen didn’t question it but said,
“(I)kind of scratched my head at that.”

Coopers inspect barrels at each stage of the production process. “If they think there’s something wrong with a barrel they can pull a barrel off at anytime,” Hansen said.

Before being wrapped for shipping, an employee will drop a light into each barrel for a final inspection before it is sent out to clients. If a winemaker is unsatisfied with a barrel, Hansen said the cooperage would send someone to inspect it.

Remy also conceded that blisters can form through the toasting process, and if they’re present when a barrel is filled they can lead to bacterial problems. “We need to avoid that from the beginning,” he said.

Canton employs a “slow and deep” toasting that’s not too hot to avoid the quick release of steam from staves. After toasting he said barrels pass through inspection stations equipped with lights to give workers a clear view inside the barrel. “It’s very simple, but it’s improving the system,” he said. “Plus, when the barrel is made, one more inspector with a controller light passes it into the bung hole.”

If workers detect a problem, Remy said they could either shave the blister out or replace the stave.

It is complex decision to pick barrels that are a good match for a wine. But beyond the sensory qualities of a barrel, winemakers also have to ensure those barrels won’t compromise the integrity of their wine.