The money will spent on buying more stock, equipment and build a clean-water plant to prepare the shellfish.
Roger Hall, from Porlock Futures, said: "In five years time we hope to be turning over about a quarter of a million oysters a year."
The grant will also enable the project based in Porlock to operate as a community interest company (CIC).
The grant has come from Power to Change, a charitable trust which gives out lottery money to help CICs being set up. In addition, £50,000 in low-interest loans has been pledged by members of the local community.
The oyster stock is bought in as "seeds" which are then placed into plastic mesh bags attached to metal trestle tables, and put in the sea.
It takes about three years for the oysters to mature before they are harvested. In about eight years time, the aim is to produce around 500,000 oysters a year.
The clean-water, or depuration, plant would be built in a shed in Porlock Weir by the end of April.
The aim over the next 18 months is to sell the shellfish to local restaurants in Somerset and Devon.
"We've got a lot of interest from a lot of restaurants, as it will be a niche product and it's going to help a lot with tourism." added Mr Hall.
A £75,000 lottery grant has been secured by a shellfish farming project in a Somerset village.