Learn the science behind:
Apparently there’s a need for manufacturers to produce more oven baked snacks, as we noticed in when comparing those with deep fried ones. But we also found out that making something in the oven, that is normally deep fried, isn’t so easy. At least, it’s pretty hard to get the same result with both methods. In a lot of cases manufacturers have to come up with smart solutions that make up for the different preparation method.
We will take a look at a few ways to do exactly that. In some cases, the solution is actually very simple, whereas in others patented solutions are used to get to a great oven snack that tastes like a deep fried on.
Difference between an oven and deep fryer
Let’s quickly recap the differences between using an oven vs. a deep fryer. The main difference between the two is the rate of heat transfer. Using oil instead of air results in more efficient heat transfer, which improves the chance for a crispy crust and results in a faster cooking time. When developing an oven baked product that doesn’t require deep frying, you will have to make up for that to still have a well cooked product with that characteristic fried crispy crust.
Whereas for some products it’s that crispy crust that’s important, in other cases it’s the fast cooking of the inside that’s required. As a result, different solution seem to be required.
Developing oven baked French fries
What do you look for in a good French fry? Probably a well cooked soft inside (no raw potato) with a crispy outside that has a nice golden brown colour.
The classic, frying approach
When made in a fryer french fries are generally made in a two step approach. The first step aims to cook the potato, thus make sure the inside of the potato has turned soft. This is done at a moderate frying temperature. Once pre-cooked, the fries are fried again, but at a higher temperature. This second step aims to make a crispy brown fry. The high temperature evaporates moisture on the outside and accelerates browning reactions. The two steps combined last around 10-15 minutes.
Most store bought frozen fries have already been fried once, so they are cooked, but just need to be heated again and get that crispy brown crust.
The oven approach
When making fries in the oven we want to accomplish those same two things: crispy outside + cooked smooth inside. This can be done in the oven, from fresh raw potatoes, without any pre-cooking. However, that can easily take an hour due to the long cooking times required. Just cooking the center will take a long time to properly heat through. And since browning only really kicks in once the center has softened (and the moisture content has reduced), that takes even more time.
A more common approach to make homemade fries in the oven is to pre-boil the potatoes (even better to do so in the microwave). That way the more efficient heat transfer of water can be used to speed up the cooking step. The final browning and crisping up will then happen in the oven and will go a lot faster.
Commercial oven baked fries
So how do manufacturers make these oven ready fries (can you actually call a fry a fry when it hasn’t been fried?)? For this story we took a look at the available assortment of french fries in the Dutch supermarket and compared the fries suitable for the oven with those that didn’t have a preparation method for the oven.
We quickly found that actually a lot of these fries are very similar. They have the same ingredients (potato + oil) and all seem to be pre-fried already (thus the internal cooking of the fry was already done). The fat content of all fries was quite similar (3-3,5g / 100g). It seems all fries, no matter the advised preparation method, had been pre-fried.
When comparing the advised preparation methods we did again find that the oven method simply takes longer than the fryer method. The fries are ready in 3-5 minutes when prepared in the deep fryer whereas they take 20-25 minutes in the oven!
So when buying oven fries, keep in mind that these have most likely been fried already, you’re only skipping the second frying step. This first frying step will have introduced some fat into the fry already and that also improves heat transfer during baking in the oven. As a result, these fries might cook faster than a plain pre-boiled potato without that extra fat to help that cooking process.
Super crunchy fries?
While doing our fries research we found a special type of fry made by the manufacturer Aviko, the so-called Supercrunch. It can be made both in the oven as well as a regular fryer. These fries are claimed to be more crunchy and that seems to be thanks to the addition of extra starches, rice flour and leavening agents. These probably form a layer around the fry which will crunch up more easily! Maybe worthwhile trying at home as well to crisp things up?
Conclusion: how to develop oven fries
Looking into the science and currently available products, it seems like developing an oven fry isn’t that complicated. In fact, they don’t seem to be any different from the regular ones! Take into account though, that even the oven fries you buy have been fried at some point.
Developing oven baked crispy kroketten
With our fries, we Dutch like to eat the snacks in the photo above, or ‘our’ kroketten (& bitterballen). These are also fried snacks consisting of a soft roux on the inside with a crispy crust on thee outside. The challenge for making a good kroket (as is the case for many other fried foods such as fried chicken), is to make a good crispy crust. When using a deep fryer a breadcrumb crust is generally enough to make this. However, when developing one to be made in the oven, it becomes a little more challenging. We take a look at the two different approaches two manufacturers took in the Netherlands.
Solution 1: Pre-fry the kroketten
This solution is a smart little trick and very similar to the one the fries manufacturers use. Pre-frying the kroketten circumvents the whole problem of making a crust without frying. The challenge isn’t anymore on how to create a crispy crust, but on how to hold on to that crust while re-heating in the oven. Luckily, these snacks tend to be frozen and that helps a lot. In frozen products the movement of water is very slow, so water doesn’t have time to travel from the inside to the outside (learn more here). Reheating something to create a crispy crust also isn’t that hard, it’s a well known trick for stale bread which can be revamped easily in the oven.
For consumers looking to find an easier way to make kroketten, it’s a good solution, for those trying to avoid a deep fryer in general, it isn’t.
Solution 2: Develop something completely new
The other brand of kroketten we looked into are those made by Kwekkeboom (see: oven & fryer versions; as of early 2020, Kwekkeboom does not make two different version anymore, instead, they only focus on the oven version!). These do not seem to be deep fried, but have instead found a completely new solution to the problem. They have found a way to make a crispy crust without frying using several inventions made by another company (CrispSensation). Below a hypothesis on what it seems like they’ve done, obviously, they are a little secretive about how it’s really done.
A quick patent search showed that indeed they seem to have found a way to make a crispy crust, without frying. We won’t dive into the details of the patent here (you can read it here), but it describes a method to make a crumb. This crumb is claimed to have a longer shelf life than a regular breadcrumb. Also, it’s explicitly mentioned that it’s suitable for frozen products mostly and for those that have to be re-heated in the oven. Which is the case for these kroketten.
However, there’s another challenge to be overcome. When kroketten are heated in the oven, the inside will become very warm. As a result, moisture will heat up and eventually evaporate. If the surrounding crust is not strong enough, the inside can leak out easily. The company seems to have another patent (two even, both pending as we write this) that solves this problem by coating the inside with a mixture with some gums that prevent water leakage.
This last kroket solution seems to be the most inventive so far, actually trying to find a way to prevent using a fryer at all! We also had a look at chips (or crisps in British English). There’s quite a few that have not been fried, however, they don’t even look and taste like the fried versions. Instead, the manufacturers probably decided it would be too hard to make a good imitation, so made it clear that it’s actually a different product. If you do find chips that have been made in the oven and look (and taste) like the fried version, let us know, we’d love to have a look at those!
The products in this comparison were compared on the website from the Dutch supermarket Albert Heijn.
For fries we included: Aviko Franse frites, Aviko Pommes frites, Aviko Oma’s friet & Aviko Opa’s friet
Article from the Volkskrant (Dutch) on the Kwekkeboom kroketten and their use of Crisp Sensation.
If you’re more of a fried chicken fan, those can be made in the oven as well!