Onions hold as much sugar as apples. Heat removes the sharp smell hiding it. Here is the timing.
Onion sweetness is not made by heat. Heat takes away the sharpness. Then the sugar already inside comes forward.
Sweet onion types like Vidalia are not higher in sugar. They are just lower in the sharp compounds.
A raw onion holds about 5% sugar. That is close to an apple. We do not notice it because the sharp smell covers it.
Cutting an onion makes sharp sulfur compounds. Heat breaks them down in a few minutes. Longer, slower heat also browns the sugar and adds depth.
Taste a strip at 2 minutes and at 5 minutes. You will feel the change yourself.
| ❌ Symptom | 🔍 Cause | 💡 Solution |
|---|---|---|
| The onion still tastes sharp | It cooked for under 3 minutes | Simmer until the strips turn see-through |
| The onion turned to mush | It was cut across the lines | Slice along the lines from root to tip |
| The dish tastes too sweet | Extra sugar on top of sweet onions | Cut the added sugar by half |
