You wouldn't classify it as anything. If you are giving beverages directly to the individuals, it is not a tax deductible contribution.
If the "group" that is doing this is a 501(c)(3) organization that has authorization from the IRS to accept tax-deductible contributions, there are two ways you could handle the expenses. The organization could pay the expenses, and you make a cash contribution to the organization to cover the expenses. Or you could purchase the supplies and donate the supplies to the organization for it to use to provide the beverages. Either way you need a written acknowledgement of your contribution from the organization.
