The incident caused severe damage to the butchery at the rear of the premises.
A spokesperson for the firm said: “As a business we are absolutely devastated by what has happened. However, everyone here is determined that we will be operational within the shortest timeframe possible.
"We have received an enormous amount of support from our customers and this has been a great comfort to everyone affected within the business.
“We are working to have the butchery up and running within the next 4-5 weeks; the restaurant and deli will remain closed until further notice, however, Feast, our takeaway food bar is open as normal.”
She added: “Our Boston shop is open as normal and also offers a home delivery service to customers who usually shop at the farm shop but may not be able to get into town. We also have online ordering via our www.bostonsausage.co.uk.”
A fire service spokesperson said: “This incident resulted in severe damage by fire to the whole building. Crews extinguished this using, five hose reels, two main jets and breathing apparatus. Ladders and the aerial ladder platform were also used.
"The fire is believed to have been caused by radiated heat from a woodburning stove that set light to the roof.”
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