To make tomato juice, start with fresh tomatoes by washing and chopping them. Then, either blanch the tomatoes to remove the skins or cook them until soft. Blend the tomatoes into a smooth puree and strain the juice through a sieve to remove seeds and pulp. Add ice water, salt, sugar, and lemon juice to taste. Chill before serving. For canning tomato juice, add bottled lemon juice or citric acid for acidity and process the jars in a boiling water bath or pressure canner following specific times and pressures depending on your altitude. The juice should be hot when poured into sterilized jars with headspace, and the jars should be sealed and processed to ensure safety. This process helps produce fresh tomato juice for immediate consumption or safely canned juice for later use.