Ace and several other insurers are facing a £40m claim after a fire gutted G&J Greenalls Distillery in Cheshire last month.
More than 100 fire-fighters, including crews from Cheshire, Staffordshire, Merseyside and Greater Manchester, were reported to have attended the blaze.
Nearby homes were evacuated in case of explosion.
Loss adjustor Teceris is understood to have been assigned the case of evaluating the damage, which is believed to be in the vicinity of £40m.
A Greenalls spokeswoman said the distillery was insured by Ace for property damage and business interruption, but stock losses were estimated at £1m.
She added: "We lost approximately two million litres of alcohol, but it is still early days in terms of determining the cost to replace buildings, lost production and staff income."
The cause of the fire is still unknown as police and fire investigations continue.
A spokeswoman for Ace said it was one of several insurers dealing with the case.