Hobby expenses are only deductible as miscellaneous itemized deductions subject to the 2% rule. You must have other itemized deductions and the total of your miscellaneous deductions must be more than 2% of your income before they will reduce your taxes.
Note that the IRS is not fond of taxpayers who try to claim self-employment income as a hobby (to avoid self employment tax) or of taxpayers who claim hobby income as if it was a business (to get better expense deductions). So be careful about changing the income around.
