Equipment
wide mouth funnel
jar lifter
1 liter measuring cup
ladle or large slotted spoon
tsp and 1/2 tsp
blender or food processor
large roaster oven, crockpot or metal pot
glass mason jars with rings and new lids
large bowl or tub
hot water bath canner with rack
Preparation of Fresh Ripe Tomatoes
cut shallow x in skin of Tomato. using a large slotted spoon place Tomato gently in a pot of boiling water for 1 minute or until skin starts to peel back from the flesh. Remove Tomato using slotted spoon and place in a bowl containing cold water until you can handle with bare hands (1 or 2 minutes).
remove skin of Tomato by sliding knife under peeling skin and pulling back. You can remove the core at the same time as well as any cat-facing, scars and blossom end rot.
cut large Tomatoes into halves or quarters and place in a large plastic freezer bag or food grade container. Freeze as soon as possible after processing.
Thawing Frozen Tomatoes
remove Tomatoes from freezer and place in a large tub, bowl or sink in order to thaw at room temperature. As the Tomatoes thaw, water will be released from ice crystals inside the Tomatoes and a clear fluid will be released. Remove fluid as it builds up every few hours, until there is no evidence of ice or solid pieces left.
Preparing Glass canning Jars
A one litre glass mason jar has the capacity for about 1kg or 2.2lbs of prepared Tomatoes. During the process of freeze/thaw and cooking, you will loose at least 50% by weight of the Tomatoes. Therefore each jar will require at least, 2.2 x 2 = 4.4 lbs of frozen Tomatoes. For quick calculations you will need 1 L jar for every 5lbs of frozen Tomatoes.
Wash glass jars, metal rings and sealing lids in soapy water. Rinse and set upside down in dish rack to dry while cooking Tomatoes.
Preparing Hot Water Bath
calculate how many jars you will be using. place empty glass canning jars (as many as 6 per batch) inside of empty water bath canner.
fill jars with water and then fill the water bath canner until the water level covers the jars (recommendation is that water covers jars by 2 inches). Leave about 1 inch between water level and top of canner so that boiling water doesn’t overflow during the process.
you may pre-heat water in bath while the Tomatoes are cooking in Roaster oven. This step may save you some time, especially if you are cooking on a stove top, which heats slower than a propane burner.
Cooking Thawed Tomatoes
placed thawed Tomatoes in a large Roaster oven or pot. set temperature at between 212’F - 250’F. monitor for water build up and remove with ladle every 15 to 20 minutes until texture or consistency is close to thickness desired in sauce. This step may take several hours.
pour sauce into a food processor or blender, and pulse until texture is homogenous or even throughout.
Acidifying Tomatoes, and adding dry ingredients
add 1/2 tsp of citric acid to each empty jar prior to filling. The citric acid will lower the pH (<4.6) and ensure safe product using hot water bath processing times recommended by regulatory agencies, food science departments at universities and research institutions.
you may add small amounts of sugar and salt for flavour enhancement at this time. I use 1 tsp of mineral salt and 2 tsp of glucose (brewing sugar) or sucrose (table sugar).
Hot Filling Jars
Place a wide mouth canning funnel in a jar and pour Tomato sauce from blender or food processor into jar until it reaches about 1/2” from the top, or the point where the jar narrows (neck) and the threads for the metal ring starts.
slide a narrow spatula or butter knife along the inside of the jar along the edge to help remove any air bubbles present after filling.
wipe the rim of the jars with a paper towel or cloth to remove any sauce that could prevent a seal between the sealing lid and rim of the jar
screw the metal ring onto the jar with two fingers until snug, but not tight (two finger tight) allowing air to escape from sauce as it is heated during the hot water process
lift canning rack into water bath half-way and hang on handles. place hot filled jars onto rack with jar lifter. Slowly lower rack with jars into water.
turn up heat and wait for water to come to a rolling boil. Start timer for recommended process time for altitude of your location. The recommended process times for standard Tomato sauce (no added wet ingredients like Onions) are available by searching the internet and on sites like National Center for Home Food Preservation. For my current location at 1800 feet above sea level, processing time for 1 quart jars is 45 minutes.
monitor water batch and adjust heat during process to maintain a slow rolling boil. when time is complete turn heat source off. Let jars remain in canner for 5 to 10 minutes. This helps prevent siphoning (tomato sauce spilling out of lid because of pressure and heat). carefully remove jars with a jar lifter onto a rack or towel and allow to cool to room temperature. This may take up to 24 hours
