Existing food freezing time prediction methods yield widely differing results at high Biot numbers (internal resistance controlling), a situation that could not be previously resolved due to lack of data. Freezing tests were carried out on slabs of Tylose gel in a plate freezer to obtain more data, which alone and in combination with previous data, were used to test the methods of Cleland and Earle, Hung and Thompson, Pham, and finite differences. Good agreement was obtained with Pham's methods and with finite differences. Biot number, freezing rate and supercooling had negligible effect on the accuracy of these methods. The accuracy of the finite difference method has been significantly improved by our new thermal property data for Tylose gel.