French Fries Bubbles?

[jr07]

Hello all,

Me and fiancee love french fries. I like to leave the skin on, and we have a lovely new de Buyer mandoline which makes cutting them the size we like a breeze.

However, today we encountered a problem. First batch went into the hot oil, no problem. Second batch, ok. However, during the 3rd batch white bubbles starting forming, and they slowly began to rise to the point where I had to quickly take the pot off the stove otherwise there would have been an accident.

I waited for the bubbles to settle, yet it seemed a point of no return. The slightest contact with the flame re ignited the bubbles to the same high level

I read somewhere that cooking oil reaches a temperature where it develops these bubbles, but of this is the case, I have two questions

1) Must I leave the cooker on medium to avoid the constant increase in oil temperature? If so, the speed at which the fries are done gets taxed... right? I kept the cooker on high heat all the time because we were hungry and the first batch took a long time (about 25 min)

2) Or is there a trick to avoid this happening?

On a related subject, I had the fries in water in the fridge over night, could this be why they took so long? Must they be at room temperature and completely dry for them to fry quicker and therefore no need to keep the flame so high for so long?

thanks a lot

J

[iswhaticrave]

I have never seen this happen and I fry quite a bit. Interested to see responses here...

[jr07]

Yes, Id love to see what replies I get

One thing to add is that the reason I ask if there is a trick to avoid this happening is that I remember a while back during a visit to a beach in south america, a lady was deep frying empanadas and I noticed she had dropped an avocado seed inside the oil. When I asked her what for, she said something that had to do with the oils temperature, but i cant remember exactly what it was!

J

[Bazza]

It is possible that you have a build up of water in your oil, do you dry the potatoes before frying?

[jr07]

Yes I dried the potatoes with kitchen paper before frying them...

does cooking oil not have a temperature at which this inevitably happens?
J

[chefbrianb]

Haven't noticed oil bubbling at a certain temperature either, but it does degrade the longer it is heated and the higher the heat the faster the degradation. Again, haven't seen this cause bubbling, but will make your fries absorb more oil, not crisp them as well as fresh oil, and give darker color and slight off flavor. Do you monitor your oil temperature?
Classic french fry technique: Cut fries to desired size/shape and soak in water overnight changing water a few times (want to remove excess surface starch.) Drain and dry before frying. Par fry potatoes at a relatively low temp about 325F to get them to cook through. Remove and drain. Heat oil to 375F and cook until crisp. Work in batches so that oil temp doesn't go too far down by adding too much potato. If a batch takes 25min. to cook sounds like that may be an issue. Good luck and happy french frying!

[jr07]

thank you chef brian, I will follow instructions next time specially with respect to oil temperature.... still puzzled as to why the bubbles though!
J

[DC Sunshine]

Only thing I can think of is - how well did you scrub the skins? Might have been as a result of something still on the skins building up after the first 2 batches, some kind of impurity that got too much for the oil.

Just a thought.

Oh, re the avocado seed, my idea is that they are nice and solid and heavy, and would pretty quickly lower the temperature of her oil if it was getting too hot, by sucking up a few degrees of heat, rather than adding more cold oil and raising the level in the fryer too much.

[elizabethbryce@]

I remember Emeril Lagasse saying not to put too much potatoes in the fryer. If possible, cook in small batches. It wasn't the oil bubbling but the water in the oil trying to dry out...just my two cents.