In a big bowl add the lukewarm water, sugar and yeast. Whisk well. Add ½ cup of the flour to the yeast mixture and whisk well. Let the yeast activate for about 10 minutes. It should bubble up and rise. Add the oil to it and mix.
In another bowl mix another ½ cup of flour with the salt. Gradually add the flour to the yeast mixture and whisk until the dough gets thick enough to be kneaded. Transfer the dough over onto a floured surface.
Knead the dough, gradually adding the remaining flour. Knead until the dough is no longer sticky, about 4 minutes, then place the dough in a oiled bowl, cover with a damp kitchen towel, and let it rest in a warm place for about 30 minutes.
Preheat oven to 200°C/400°F degrees.
Transfer the dough on a floured surface and roll it into a thin rectangular shape. Cut long strips of dough using a sharp knife or pizza wheel. Gently roll each strip with your hands, to make a thin breadstick. Repeat the process with the remaining dough.
Place the bread sticks on a baking sheet covered with parchment paper, and sprinkle them with optional sea salt. You can also brush them with a little extra-virgin olive oil for a super crunchy result.
Bake in the oven until golden and crisp, about 18- 20 minutes.
Remove the grissini from the oven, allow them to cool on a cooling rack, then serve.
Notes
You can leave the dough to rise overnight in the fridge. Bring it back to room temperature, then shape it and bake the breadsticks.
You can freeze the dough after kneading: freeze in an airtight freezer bag. Defrost completely, then let the dough puff up a little again, then shape into sticks and proceed with the baking.