When Grill returned to Sweden in 1768, he first lived in Stockholm where he occupied himself with trade.
He owned a malmgård (suburban manor) at Ersta in the south part of Stockholm, where he established a crucible steel factory with the help of Bengt Andersson Qvist in 1770.

Grill married Lovisa Ulrika Lüning (1744–1824) in Stockholm in 1772.
They had ten children.
She was the daughter of wholesaler Johan Christian Lüning and Margaretha Sabbath.
In 1775, Grill sold the manor and the steel factory to Qvist and moved to Godegård where he had bought the manor and the ironworks from the estate of Jean de Geer.
In doing so he followed the pattern of other supercargos who made their fortunes abroad during a short period of time in the East India trade and on their return invested their money in Swedish factories and farms.

Aside from renovating the factories in Godegård (the largest ironworks in Östergötland) he also had an English park planned and built at his manor in Godergård.
The park had an orangery, canals, bridges and pavilions and was modelled after the larger park at Drottningholm Palace with its Chinese Pavilion.
The Godegård estate also included Mariedamm with the Trehörnings blast furnace and the De Geersfors manufacturing house.
Grill also bought the Bona estate in Västra Ny, where he built a wrought iron factory and the Medevi seat farm in 1779, (sold the following year).
In 1782, he bought the Flerohopp ironworks.

Grill established a small scale trade monopoly at Godegård in 1775.
Before he became owner of the ironworks, the farmers around Godegård had refined the wrought iron from the factory into large quantities of nails using small trip hammers.
The nails were sold in Askersund.
As a trader Grill would not abide this.
First he decreed that the farmers had to buy all their goods at the ironworks' general store.
Second, he forbade the farmers and tenant farmers to sell nails to the merchants at Askersund, at that time a center for nail trade.
In this way Grill assumed control over all nail trade himself.

Jean Abraham Grill died on 12 March 1792, in Norrköping under "mysterious circumstances" and was interred in the Grill family grave at the Godegård Church.
When Grill died, his wife Lovisa Ulrika took over and ran the ironworks and factories until their children succeeded her.
When Grill returned to Sweden in 1768, he first lived in Stockholm where he occupied himself with trade. He owned a malmgård (suburban manor) at Ersta in the south part of Stockholm, where he established a crucible steel factory with the help of Bengt Andersson Qvist in 1770.
Grill married Lovisa Ulrika Lüning (1744–1824) in Stockholm in 1772. They had ten children. She was the daughter of wholesaler Johan Christian Lüning and Margaretha Sabbath. In 1775, Grill sold the manor and the steel factory to Qvist and moved to Godegård where he had bought the manor and the ironworks from the estate of Jean de Geer. In doing so he followed the pattern of other supercargos who made their fortunes abroad during a short period of time in the East India trade and on their return invested their money in Swedish factories and farms.
Aside from renovating the factories in Godegård (the largest ironworks in Östergötland) he also had an English park planned and built at his manor in Godergård. The park had an orangery, canals, bridges and pavilions and was modelled after the larger park at Drottningholm Palace with its Chinese Pavilion. The Godegård estate also included Mariedamm with the Trehörnings blast furnace and the De Geersfors manufacturing house. Grill also bought the Bona estate in Västra Ny, where he built a wrought iron factory and the Medevi seat farm in 1779, (sold the following year). In 1782, he bought the Flerohopp ironworks.
Grill established a small scale trade monopoly at Godegård in 1775. Before he became owner of the ironworks, the farmers around Godegård had refined the wrought iron from the factory into large quantities of nails using small trip hammers. The nails were sold in Askersund. As a trader Grill would not abide this. First he decreed that the farmers had to buy all their goods at the ironworks' general store. Second, he forbade the farmers and tenant farmers to sell nails to the merchants at Askersund, at that time a center for nail trade. In this way Grill assumed control over all nail trade himself.
Jean Abraham Grill died on 12 March 1792, in Norrköping under "mysterious circumstances" and was interred in the Grill family grave at the Godegård Church. When Grill died, his wife Lovisa Ulrika took over and ran the ironworks and factories until their children succeeded her.
Jean Abraham Grill