Potato Chips: Fried, Kettle Fried or Continuously Kettle Fried

A Heat and Control batch fryer, a typical piece of equipment for the industrial production of kettle style potato chips.

A Heat and Control batch fryer, a typical piece of equipment for the industrial production of kettle style potato chips.

March 18, 2009

In a matter of weeks, world's largest manufacturer of Potato Chips, Pepsico (Frito-Lay) will launch a major advertising campaign for a new Chips brand in the United Kingdom, Red Sky Potato Chips.


This product will be positioned as  premium "sharing" chips , the kind of chips (or crisps in the UK) you serve your friends if they come over to visit, rather than the chips you eat by the bag at lunch (a common occasion to eat chips in the UK).

Red Sky Potato Chips

Red Sky Potato Chips


Simon Quirk of Market Research Company TNS states in the Independent: "The average packet of crisps isn’t going to look good when you’ve got friends coming round. The flavours and packaging [of the premium crisps] are more exciting and they’re more appealing for that sharing occasion.”

According to TNS, (UK) shoppers spent £368m (524m USD) on ‘sharing crisps’ in the 52 weeks to 25 January this year – up 8.7 per cent.

Interesting about these potato chips is also their high environmental profile and the fact that they are not launched using the Walkers brand, used for most of Pepsico's potato chips in the UK.  However, the reason I made these potato chips the topic of today's Newsletter has nothing to do with all this, but with the way Red Sky Potato Chips are manufactured.

Let me explain: So far there were two different ways to fry potato chips: The continuous way (regular chips) and kettle fried potato chips.

Continuous potato chips fryer, product moves in and out constantly

Continuous Potato Chip Fryer product moves in and out constantly


In the continuous way to produce potato chips, a continuous stream of cut and washed potato slices enters the fryer and move through the fryer in about three minutes, partly free floating, partly transported by a belt and end up at the other side fully fried where they are continuously removed.

Kettle Chips fryer: potato chips are fried batch by batch

Batch Fryer, for the production of kettle chips. The chips are fried batch by batch


Kettle fried potato chips, are sliced a bit thicker, not washed and are fried "kettle by kettle": the fryer is filled with uncooked slices,  and the slices are fried and stirred until all water is evaporated. About 7-9 minutes later all product is removed from the kettle fryer at once and the process starts a-new by filling the fryer with a batch of new unfried slices. The kettle frying process is more suitable for smaller scale operations and the chips have more bite, have a harder texture.

Pepsico's new Red Sky Potato Chips are fried in a new way: these potato chips are continuously kettle fried. The idea behind continuously kettle frying is to replicate the typical time-temperature profile of the classical kettle frying process, but in a continuous fryer. This is not as easy as it may seem, since in the traditional kettle frying process the frying oil temperature drops a lot at the beginning of the frying process and then increases again towards the end of the frying process. This results in a U-shaped temperature profile.

Nevertheless, Pepsico figured it out! And although they never told me how they exactly do it (and just to be clear, I never asked!)  this patent application for a continuous kettle frying process sheds some light on how it could be done: by manipulating oil flows they create potato chips that are crispier, more tasty, contain less oil in a process that is more controlled and is also more friendly for the frying oil.

Therefore, Red Sky Potato Chips should be considered a major breakthrough in the technology for the production of potato chips.

Can't wait to lay my hands on a bag of these chips.

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