After the war Typhoo continued to expand, moving its packaging business into larger premises with the latest packaging machinery. Blending was still carried out by the Ceylon agents in Colombo.
In 1932 John Sumner was knighted in recognition of his charitable services that included the founding of the John Sumner Trust, devoted to work with education, literature, art and research. The award also recognised John's setting up of the Colehaven Endowed Homes for Gentlewomen and his work with hospitals. John celebrated his knighthood with a staff party and a bonus for all his employees.
In the early 1930s problems arose with the quality of the tea being supplied from Ceylon. It was discovered that the agents in Ceylon were not adhering to the quality control requirements put in place by Typhoo. They were, in fact, purchasing inferior teas at low prices and then overcharging for the blend in order to make a profit.
The matter was followed up by John Sumner's son, J R Hugh Sumner, and the situation was finally resolved in January 1933 when the contract with the Ceylon agency was terminated. The newly appointed agents, Carson & Co. Ltd took over the responsibility for buying and blending and continued for many years until market trends led to less Ceylon tea being required for the blends. Around this time Typhoo was increasing in capacity and was able to house blending equipment in its works in the Birmingham Canal Basin. After the blending machinery had been completely installed in 1934, Typhoo began to employ its own tea taster/blenders.
Now in advancing years, John Sumner senior visited the works less and less and died on 11 May 1934. After the death of his father, J R Hugh Sumner was elected chairman of Typhoo.