California smoke taint test situation ‘unacceptable’ for growers

The California Association of Winegrape Growers has said that losses incurred by vine growers as a result of wineries demanding smoke taint tests before accepting their grapes are “unacceptable”.

The statement, sent out by the president of the CAWG, John Aguirre, last week stated that “numerous” growers have reported cases of wineries not accepting grapes until laboratory tests have been conduced to ascertain if smoke compounds are present.

It follows news of widespread wildfires across California this season. According to Cal Fire, over two million acres of land have burned this year, with a total of eight fatalities and 3,300 structures destroyed.

While the initial impact on wineries and vineyards has been described as “minimal”, it is too early to access the affect and extent of possible smoke taint.

CAWG said it is concerned that growers in the state could face financial hardship. It described the challenges faced by both vineyard owners and wineries as a result of the wildfires as “unprecedented”.

President John Aguirre said: “The few commercial labs serving the industry are backlogged, with wait times of three or more weeks to test and report the results for new grape samples. In other instances, wineries are delaying harvest and grape deliveries pending the completion of small-batch or micro-fermentations of grapes and resulting
analyses.

“These delays – in addition to wineries demanding test results – mean many growers face the prospect of significant crop losses and economic injury. This is unacceptable.”

Aguirre added that unless it was specifically mentioned in a contract, “no buyer should believe they are entitled to reject a grower’s grapes based on concerns over smoke damage without corroborating evidence to indicate those grapes have, in fact, been damaged”.

He stressed the unpredictable nature of smoke taint, adding that smoke exposure did not necessarily mean the grapes had been damaged. He urged the need for transparency, clear communication and compassion between members of the industry, stating: “The challenges posed by recent smoke exposure events do not provide license to buyers to cast aside their contractual obligations to growers.”

Once such lab under strain is ETS. According to a notice posted on its website, it is currently reporting on samples sent in on 25 and 26 August. Grape samples received early this week won’t receive results until 17 October, while wine samples will have a faster turnaround of 28 September. Those who are not ETS clients face a much longer wait, with smoke test samples being processed “no sooner than November”.

Smoke taint occurs when so-called free volatile phenols, such as guaiacol, are absorbed by grapes and bind with sugars to produce glycosides. During fermentation, these glycosides break down, releasing the volatile phenols and smoky flavours into the wine. It is thought these smoke taint aromas and flavours are concentrated in the grape skins. This explains why smoke taint is often not detected in grapes, but is in wine.

As reported last month, the California Wine Institute and Sonoma County Winegrowers said it was still too early to tell the impact.

The California Wine Institute noted: “Multiple considerations determine the potential impacts of smoke exposure including proximity of smoke to the grapes (vs. smoke being in the upper atmosphere), freshness, density and duration of the smoke, wind direction and stage of development and variety of the grapes. Air quality in wine communities, which is usually late-stage smoke from remote fires, does not directly correlate to impacts on grapes.”