Does the oven temperature for a lasagna really matter?

Question

Of all the things that go into my oven, a lasagna is one of the more "wet" or saucy dishes. When a fully baked lasagna comes out of the oven, it still has quite a bit of water content remaining.

So, this made me wonder if it is true that, during the baking process, most of the lasagna (ignoring the cheese layer on top which does undergo browning) likely never exceeds 212 F / 100 C in temperature (boiling point of water)? And if this is true, the oven temperature doesn't really matter as much as the cooking time does (i.e., it takes the same amount of time to cook in a 400 F oven as a 325 F oven since the core temperature of the lasagna is capped at 220 F). Is this true?

If this is the case, then could you reasonably cook a lasagna at an oven temperature below the Maillard reaction (say, 275 F) and simply broil the top for a few minutes at the end to brown the cheese layer - and still achieve a similar result as you would get for a regular oven temperature (say, 350 F)?

Answer 1

While the core temperature will be capped at or around boiling, adding additional heat will increase the rate of boiling, if not the overall temperature while it cooks. Water takes ~40 kJ/mol to convert it from 100 C liquid to 100 C gas, so inputting more heat will increase the rate of that effect.

Consider the following - if you placed your lasagna in the center of the sun, you’d expect it to be incinerated fairly quickly. As such, there exists some range between “cooking slowly” and “cooking quickly”, determined by the oven temperature. Additionally, you're not really getting the majority of the food anywhere near boiling, since the target internal temperature is around 160-165 F. So while you're limited to around 212 F by the water content, the majority of the dish won't reach that temperature.

To summarize, I would expect that you could probably cook it at a lower temperature then broil for a similar result, with a caveat. If you maintain the same cook time, you should expect to have more water content in the final product and a possibly undercooked result. See here, for a little more on baking at a lower temperature. Oven temperature is critical to determining cook time, rather than being irrelevant

Answer 2

The short answer to your question is "yes", you can use a low oven and broil the top. That is my preferred method...lower oven temp, covered lasagna, remove foil and broil. The physics is more difficult to wrestle with. First, there is a lot of evaporative cooling happening around your lasagna (or any food in your oven), which results in temperature around your food far lower than the oven temp., and because lasagna is wet, it will take a while for that temperature gradient to change. Here is where covering will help. Also there is wide variability in oven temp vs. oven setting on most ovens. That makes any sort of precision almost impossible for most people. Finally, lasagna is generally not a dish that requires cooking precision, and it is probably better to reduce liquidity in the construction step, rather than rely on evaporation in the oven. So, in short oven temperature in the range you are specifying probably doesn't really matter in any practical sense (There might be a small time savings...but a significant one?). One is generally just looking to heat through and melt cheese (if included). So, covering with foil is your friend here. If you desire a browned top (and why wouldn't you), use the broiler to finish.

Answer 3

My guess: Heating of the center of the lasagna should be determined by a diffusion behavior, i.e. the energy flow is roughly proportional to the temperature difference of outside and center. The temperature of the wet sauce on the outside will be around boiling regardless of oven temperature, so the center cooks at a similar rate.

Less fluid would raise the temperature, if there isn't enough water/liquid to evaporate and cool the solid bits.

The cooking time also depends on stacking height and dish size.

The tastiness of the outcome is determined by what happens to the outer section of the lasagna after the water has evaporated and until the center is cooked.

Answer 4

Yes, the oven temperature matters.

It takes time for the oven's heat to reach the center of the lasagna, so depending on the oven temperature, the temperature gradient inside will vary.

I never cover lasagna with foil. Usually doing that means it ends up too wet. This especially applies to vegetarian lasagna, as typical minced beef replacements (zucchinis/mushrooms/eggplants/spinach) have more moisture in them than the beef does.

Large temperature gradients might mean the outer edges become hard and/or burnt.

Small temperature gradients usually mean the opposite, and you end up with a soggy, sloppy mess. Lower temperatures also means the lasagna has a longer time to firm up; you'll draw moisture from it more evenly. Go too low, and you can't get a crust on top, however, you can fix that if your oven has a grill by grilling for 5 minutes after the dish is cooked.

Typical lasagna oven temperature ranges from 160-200C (320-390F), and baking times range from 25-75 minutes. You can always lower the temperature to 150C if the lasagna browns but is still undercooked inside upon inspection.

Things that change the optimal temperature:

Pasta type

• Pre-prepared store bought lasagna tends to cook quicker.
• Dried pasta sheets tend to be middle of the road.
• Using fresh home-made pasta makes things take longer.

Fillings

• Spinach/Tomato combinations are the most liquid.
• Then using firmer vegetables.
• Meat tends to be driest.
• The thickness of the béchamel can be adjusted for these (use extra flour/butter when using both spinach and tomato sauce).

Size

The bigger and blockier the lasagna, the longer the time and the lower the temperature. I wouldn't make more than about 8 portions in one huge oven dish; better to make multiple smaller dishes.