Place chickpeas in a large pot and cover with cold water (by at least 4 inches/10 cm) and let sit at least 6 hours or overnight
Drain and rinse the chickpeas, add back to the pot, and then sprinkle with the baking soda
Place the pot with the chickpeas over high heat and stir until the skins start to break and the chickpeas dry out (about 4 to 5 mins)
Add enough cold water to cover the chickpeas by 4 inches and then bring to a boil
Reduce heat and simmer for about 45 minutes or until the chickpeas are tender
As they cook, skim and discard skins that float to the top
Drain the chickpeas and rinse with cold water. Pick out and discard any loose skins, but don't go crazy here.
Add the chickpeas to a food processor and pulse until a thick paste forms. Add tahini, lemon juice, garlic, and salt and then process for about 2 minutes
Then while the machine is on, add the water slowly and process until the hummus is completely smooth, about 2 minutes.
Taste the hummus and adjust seasoning to taste.
Serve drizzled with olive oil.