Add 8 cups of water, black tea bags, and a half cup of blackberries to the Instant Pot and stir to combine. Add the lid, lock it into place, and switch the vent to "Sealing." Set the "Manual" setting to 5 minutes.

While the tea is brewing, make the blackberry honey simple syrup. Add the remaining blackberries, honey, and 1/2 cup water to a saucepan. Cook over medium heat, gently pressing on the blackberries to release their juices while continually stirring the mixture to combine.

After about 4-5 minutes, the honey should be completely melted and the mixture will be slightly thickened. Remove from the heat and set aside.

When the cooking time on the Instant Pot is complete, allow the pressure to release naturally for 10 minutes, then do a quick release to release any remaining pressure.

Carefully, stain the hot tea with a fine mesh strainer. Pour the reserved liquid into a large, heat-resistant pitcher and sweeten with the blackberry honey simple syrup, to taste.

Add the fresh lemon juice and stir to combine.

Serve over ice with fresh blackberries and a sprig of fresh basil for garnish!