Deep Frying, Thermal Mass, and other thoughts

[LetterRip]

The standard recommendation for deep frying is a minimum of 1:10 food to oil/fat, to prevent the oil from cooling too much when the food to be fried is added.

http://www.dgfett.de/material/optimum_frying.pdf

I'm curious if drastically increasing the thermal mass of the cooking container can be used to reduce that requirement?

Ie set your deep frying pan on a heavy steel block, then we can recharge the heat to the oil quite rapidly.

Anyone done any experiments, or have any insight?

Another question/thought - if we prewarm or precool the item to be fried. For the thermal mass question it should decrease it it we prewarm the food to be fried, but what impact will in have on flavor, same question of flavor effects on cooling the food before frying it.

My thoughts are that preheating might reduce the moisture content slightly so slightly less moist.

Another deep frying question/thought - anyone doing their cooling on a rack/elevation with circulating hot air to reduce oil absorption? I'm also curious if industrial cooking facilities use hot air blowers to blow off the oil of fried items before cooling them.

[Shalmanese]

Home deep frying and commercial deep frying are such different beasts that they might as well be separate cooking methods. With commercial deep frying, you care about volume of production, longevity of oil, reliability & reproducibility and simplicity. With home frying, you're rarely cooking more than 3 - 4 portions and batching is fine, you're generally attending to the frying rather than doing "set and forget" and you don't care as much if you slightly abuse the oil.

Given that, how home frying generally tends to work is that you bring the oil up to above the target temperature, drop the food in which is drop it down to target temp and then regulate the heat to maintain target temp for the duration of the frying. With this approach, you don't need 1:10 food to oil ratio, generally, you just need enough to cover the food. Most frying oils degrade around 450F and general frying temperatures are around 350 - 400F, overshoots tend to be around 15 - 25F so you have a bit of headroom to play around with. You could try to add more thermal mass to the equation but all that does is reduce the overshoot which might be slightly kinder on the oil but doesn't get you much beyond that.

[HungryC]

Regarding the item to be fried's temperature: results will vary radically depending on the items being fried. Tender stuff like shrimp or fish is generally chilled before coating/battering, as the "stuff" on the outside sticks better to cold food. Try battering a room temp piece of fish then frying--the coating will often slough right off, leaving a naked filet bobbing around.

[IndyRob]

What about a vessel with insanely thick cast iron walls - like a miniature version of an old mortar cannon? (extra credit for an insulated outer coating)

Could we rely on added metal to keep up the thermal inertia?

[LetterRip]

What about a vessel with insanely thick cast iron walls - like a miniature version of an old mortar cannon? (extra credit for an insulated outer coating)

Could we rely on added metal to keep up the thermal inertia?

IndyRob - the source of the thermal mass - whether it be a heavier pan, or by sitting your pan on a large hunk of metal as I suggested above - doesn't really matter much, so yes a vessel with thick iron walls will better maintain the 'thermal inertia'.

[LetterRip]

Given that, how home frying generally tends to work is that you bring the oil up to above the target temperature, drop the food in which is drop it down to target temp and then regulate the heat to maintain target temp for the duration of the frying. With this approach, you don't need 1:10 food to oil ratio, generally, you just need enough to cover the food. Most frying oils degrade around 450F and general frying temperatures are around 350 - 400F, overshoots tend to be around 15 - 25F so you have a bit of headroom to play around with. You could try to add more thermal mass to the equation but all that does is reduce the overshoot which might be slightly kinder on the oil but doesn't get you much beyond that.

That makes sense. It seems like many home cooks doing stove top frying add too much food for the oil, resulting in the temp dropping too drastically and thus allowing oil to seep in and making the food greasy. So I was thinking by suggesting a block of metal for added thermal mass, this problem might be alleviated. (Obviously they could instead reduce the number of pieces cooked at one time and increase the oil temp as well).

[Martin Fisher]

I've looked and looked and looked for years and haven't found a stove top frying vessel that I think is perfect.

I think that a heavy, tall, flat-bottomed cast iron bean pot or potjie would come closest to perfect (hold temperature well with a minimum of oil) but I haven't found a good affordable one.

[dcarch]

I've looked and looked and looked for years and haven't found a stove top frying vessel that I think is perfect.

I think that a heavy, tall, flat-bottomed cast iron bean pot or potjie would come closest to perfect (hold temperature well with a minimum of oil) but I haven't found a good affordable one.

Try a wok.

1. The large diameter of a wok minimizes splatter.

2. The round bottom allows large or small amount of frying.

3. The rack that sits on the wok allows draining of oil after frying. It works better than draining on paper towel because hot oil is more fluid.

dcarch

[MSRadell]

I've actually found that a cast-iron Dutch oven, like those used for camping work very well on top of a gas burner for deep frying. They have a good bit of mass and can hold a decent volume of oil. They are not overly expensive and are extremely rugged. They certainly work much better than any of the electric countertop deep fryer's I've seen.

[Martin Fisher]

I have woks and numerous cast iron Dutch ovens and chicken fryers, they work okay.

What i'm interested in is something perfect for small batch deep frying that's relatively deep and narrow so it requires little oil, yet heavy enough to maintain temperature well.