The acquisition is part of a plan to future-proof the business by diversifying beyond jams and preserves, joint md Ian Thurgood told FoodManufacture.co.uk.
“Although the premium end of the jams and preserves market - which is where we are - has seen some growth, the retail market in general is pretty static, so we're looking to explore other growth opportunities.
"This will be through developing new products internally and expanding into new channels - for example we've increased sales to the foodservice sector by 30% with the development of mini jars for hotels and other outlets - but also through buying businesses with high-quality established brands."
Coles, which makes traditional Christmas puddings, premium puddings and cakes for the UK and export markets, employs 20 staff at a purpose-built production unit at Great Chesterford near Saffron Walden.
Coles md Chris Cole will stay on to run the business, said Thurgood. “We didn't buy Coles to go in and make wholesale changes, it's a well-run business with a super facility. It's more a case of bringing in financial and management support and marketing assistance. We can also help to drive export sales."
Wilkin & Sons, which celebrates its 125th anniversary this year, first moved into the bakery market in 2003 via an investment in handmade cake maker Passionately Cakes.
This is now part of Wilkin & Sons’ Tiptree Patisserie business (formerly Raven Patisserie), which makes cakes and patisserie for hotels, cafes, restaurants and event caterers.
The firm, which owns tearooms at Tiptree, Heybridge Basin and Dedham, also runs a £1m fresh fruit business selling produce grown on its estate. Significant sums of money have also been pumped into a new honey-packing operation, cold store and IQF (individually quick-frozen) fruit plant, said Thurgood.
Excluding the Coles business, sales at Wilkin & Sons were around the £25m mark, he said. "Last year was more difficult but this year has been very strong; we've had strong top and bottom line growth. We're also trying to be more efficient and effective.
"For example, this year we were completely self-sufficient in strawberries, we grew all the strawberries we needed for our jam ourselves, which has helped us maintain quality and reduced costs as we are not having to import them anymore."