Fried egg in an 8 in skillet: 300, 340 and 380 °F surface

01Abstract

Nine eggs were fried one at a time in an 8 in cast-iron skillet at three surfaces: 300 °F, 340 °F and 380 °F, with 1 tsp canola oil in each case. The pan was brought to temperature on the inner ring at low dial and the temperature re-checked before every egg. Stick index was scored after lifting with a thin steel spatula; a lid was used for the last 60 seconds of each egg to set the white.

02Variables

Hypothesis Eggs stick because the pan is too cold or too hot, not because the seasoning is thin; 320 to 340 °F is the window where nothing sticks.

03Process

1. Preheat the empty pan on the inner ring at low for 4 minutes, then read the surface and adjust the dial by a quarter turn until the target is held for 30 s.
2. Add 1 tsp canola and swirl for 3 seconds; the oil should coat thinly and show faint movement, not shimmer hard.
3. Crack the egg into a cup and slide it in from the rim so the white lands as one piece instead of splashing.
4. Leave it alone for 90 seconds, then cover with a lid for 60 seconds to set the top of the white.
5. Slide the spatula flat under the white and lift. Score how much residue is left on the iron and wipe the pan before the next egg.

04Observations

• 300 °F: the white spread and stayed translucent for 70 s, the yolk took 3 min 20 s to set; release was clean but the edge was pale and rubbery.
• 340 °F: white opaque in 35 s, lacy brown edge in 70 s, lid 60 s, and the egg slid onto the plate with no spatula pressure at all.
• 380 °F: the white bubbled hard at the edge within 10 s, and three patches tore loose at the lift, leaving a pale film on the iron.
• The 380 °F pan needed a 60-second rest off the heat before the next egg, which is why batch cooking eggs on high always degrades.
• Canola at 340 °F never smoked; at 380 °F it smoked lightly from 40 s onward, which is the practical sign that the pan is above the oil's comfortable range.

05Conclusion

The non-stick reputation of well-seasoned iron is really a temperature claim: 340 °F holds the egg on a thin film of oil without welding it, and the same pan at 380 °F will stick even with a good seasoning layer. Use the inner ring at low and check the surface with a gun the first few times; once you know the dial position, the gun is optional. Two eggs at once in an 8 in pan drops the temperature by about 30 °F, so add 20 seconds to the timing rather than turning the dial up.