To develop more cost-effective and environmentally friendly strategies to prevent the formation of gas hydrate plugs in oil production pipelines, a better understanding of the mechanisms of plug formation is needed. This paper presents broad-band permittivity measurements of hydrate formation in water-in-oil emulsions. The experiments were conducted at atmospheric pressure using dead crude oil and diesel fuel, with cyclopentane as hydrate former. However, the use of dielectric probes employed in this work can be extended to more realistic systems, as they are able to withstand high pressures and harsh chemical environments. The results show that broad-band permittivity measurements can be used to detect hydrate agglomeration and formation of hydrate deposits in oil-dominated systems. By applying existing dielectric mixing models, the fractions of oil, water, and hydrates can be estimated.