Wash and hull the strawberries and place them in a large pot. Sprinkle the sugar over the top and stir to distribute.
Cover the pot and let the strawberries macerate in the sugar at room temperature for up to 6 hours. If they need to sit longer, put them in the fridge overnight.
Prepare a water bath canner and canning jars, and heat the canner water to about 180 degrees F.
Put the pot on the stove and stir in the citric acid, if using. Bring the strawberries and their juice to a simmer, stirring as little as possible, and cook for about 1 minute until the berries are heated through.
Pack the hot berries tightly into the jars and cover them with the hot juice, leaving 1/2 inch headspace.
Remove air bubbles, adjust the headspace, and seal with two-part canning lids.
Process in a water bath canner, pints for 10 minutes or quarts for 15 minutes, adjusting for altitude (see notes).
Turn off the heat, take the lid off the canner, and let the jars sit in the water for 5 minutes before lifting them out.
Notes
Recipe source: Follows the tested process for whole strawberries in the Ball Blue Book Guide to Preserving and the Bernardin Guide to Home Preserving. NCHFP doesn't have a strawberry recipe.Hot pack only: Strawberries are always heated in their juice before they go in the jars. There's no tested raw pack for them.Yield: 4 cups of whole, hulled strawberries fill about 2 pints. A quart jar takes 2 to 3 pounds of berries, depending on their size.Sugar: Sugar is optional, but the flavor is much better with a little, since some of the berries' sugar goes into the canning liquid. You can reduce it, but I'd suggest at least 1 tablespoon per pint. For very sweet dessert berries, use up to 3/4 cup or even 1 full cup per quart of berries.Without sugar: Heat the berries with about 1/4 cup of water per 2 pounds until they release their juice, or use strained strawberry juice as the canning liquid. They come out softer.Citric acid: It isn't needed for safety, but it helps the berries keep their color and flavor in storage.Altitude adjustments: Processing times for pints and quarts in a water bath canner.
0 to 1,000 feet: 10 minutes for pints and 15 minutes for quarts
1,001 to 3,000 feet: 15 minutes for pints and 20 minutes for quarts
3,001 to 6,000 feet: 15 minutes for pints and 20 minutes for quarts
Above 6,000 feet: 20 minutes for pints and 25 minutes for quarts
Storage: Canned strawberries soften and darken in long storage, so they look best within the first few months.