Tomato paste recipe in the canning category

: Peel, core and chop tomatoes. Measure. You should have 8 quarts. Add salt, place in large pot and simmer over low heat for about 1 hour. Stir often to prevent sticking. Remove from heat and press through a fine sieve or put through food mill. Return to kettle and continue to cook very slowly until paste holds its shape on a spoon, about 2 hours. Stir occasionally to prevent sticking. Spoon into clean, hot jars, leaving 1/2 inch headspace. Seal. Process in boiling water bath for 30 minutes.