Here's the recipe I found in a 1963 Freezing & Canning Cookbook (haven't tried it): Wash, scrape and rinse small freshly dug new potatoes. Boil 10 minutes in water; drain. Hot Pack Only: Pack hot to within 1/2" of jar top. Add salt (1/2tsp to pints; 1 tsp to quarts). Cover with fresh boiling water. Leave 1/2" head space. Adjust lids. Process in pressure canner at 10 pounds pressure (240 degrees F). Pint jars -- 30 minutes. Quart jars -- 40 minutes. Remove jars from canner and complete seals unless closures are self-sealing type.