We eat pasta and rice much more often than potatoes, but when we do eat potatoes we most often eat them roasted. This preparation brings out the taste of the potatoes themselves and gives them a nice crispy crust without using a lot of oil.
There are many variables you can change when making roasted potatoes: oven temperature, salting before or after, waxy or floury potatoes, etc. I decided to do a series of experiments to find the optimal recipe. This first installment is about salt: is it better to salt the potatoes before or after roasting? Instinctively I have always salted afterwards, but I was curious if that was really the best way.
For all experiments I will use a basic recipe of potatoes, olive oil, and salt. In this case I used floury potatoes.
I peeled the potatoes and cut each in half to make the comparison as fair as possible (even though the potatoes came from the same bag). I roasted one half of each potato with just olive oil and added salt afterwards, whereas the second half of each potato was salted before roasting.
I cut the potatoes in quarters lengthwise and rinsed them in cold water to remove excess starch.
I dried the potatoes with paper towels and tossed the first batch with olive oil only. I like to toss them in this measuring jug because the handle makes it easy to toss them, but you could use any bowl you like. You only need a little olive oil, a tablespoon or even less per person. They just need to be coated with oil. The oily coat is needed to actually roast the potato. If you would put them into a hot oven without any oil, they would dry out rather than roast because the temperature of the outside of the potato would be limited to 100C/212F until all water had evaporated.
I tossed the second batch with olive oil and salt.
I preheated the oven to 200C/390F and arranged the potato wedges on a baking sheet lined with parchment paper. I arranged the wedges with one of the flat sides down. The salted batch is on the right-hand side.
I roasted the potatoes for 20 minutes at 200C/390F in a static oven (i.e. without using the forced air). Then I took them out of the oven.
I flipped each wedge onto the other flat side. As you can see, the side that was on the baking sheet has browned more. This flipping step is needed to brown the potato wedges evenly.
I then returned the potatoes to the oven and continued to roast them until golden brown on all sides, another 20 minutes at 200C/390F.
I then salted the first batch on the left-hand side.
We tasted the potatoes and agreed that post-salting is better than pre-salting. Salting before or after clearly makes a difference. The outside of the post-salted potatoes is more crispy and has a nice bite to it, whereas the outside of the pre-salted potatoes is tough and leathery. This is probably caused by the salt drawing moisture out of the potato, which prevents the outside from crisping up properly. It turns out that my instincts had been right.
Although the potatoes were pretty good this way, I will do more experiments to see if I can make improvements. Unfortunately I don’t have two ovens, so I have to think of a clever way to compare potatoes roasted at different temperatures.
Great experiment. I’ve never considered salting potatoes after roasting, I always salt before but I think I will try salting afterwards next time. You have done a service to potato roasters everywhere
I usually add seasonings like garlic, herbs, paprika before roasting. Do you think that is still a good idea?
I don’t think those other seasonings will affect the roasting as much as the salt, so I think it’s probably okay. This is something I’ll try as well in my next experiments.
I usually salt after. Not for any reason except that I actually like the taste of salt. That is, apart from it’s flavour enhancing properties. Great experiment to prove it once and for all.
Best,
Conor
Good experiment …. I’ll make a mental note of this!!
I’ve always seasoned my potatoes before roasting, rather absentmindedly. It makes complete sense that doing so would not enhance the potatoes’ texture at all. Thanks, Stefan. Today you taught me a better way.