Barnett III’s brother-in-law was Richard Hopkins (1763-1810), head cook at Trinity Hall and Caius College. He was also a brewer, and made and sold brawn – a meat jelly made from the head of a pig or calf.
In 1805 the renowned essayist and food lover Charles Lamb (1775-1834) was given some of Hopkins’ brawn by a friend as a present. Lamb wrote a fulsome letter of thanks in praise of Mr Hopkins and his delicious meat produce. After his death, Richard’s widow Sarah continued all his businesses, including as cook at Trinity Hall and Caius College.