Cafe owners Ian and Jonathan Corlett said the size of the proposed rise was something that would "certainly put people into problems".
Ian Corlett said: "It's a stupidly high amount as a percentage, it's too high for any of us small businesses because we don't have the ability to absorb that sort of overhead overnight."
He said it "remains to be seen" what affect it would have on their business "because we can do more hours ourselves theoretically, which reduces the need to pay people".
Jonathan Corlett said basing the rise on the median earnings "makes no sense" when it included public sector earnings, which were higher than those paid to many in the private sector.
"Government being the largest employer on the island skews that average quite a lot," he said.
"And if you're basing it off a median percentage that median is going to go up as the minimum wage goes up, meaning it will just go higher and higher, and it's going to end up well above inflation and well above the cost of living."
He said while "that's not a bad thing in itself", the government "needs to start reducing the cost of living and not just increasing wages".
The Minimum Wage Committee said the size of the rise would be "unsustainable for a cross section of low paying employers", and could lead to fewer hours being available to staff, especially to disabled workers.
Its letter to the enterprise minister said it would also be "likely to have a negative effect upon inflation than a positive effect".
However, the committee said it welcomed the break away from aligning the minimum wage with the living wage, and recommended "further finessing of the policy application to further help business, and support jobs".