Experiment One: To Olive Oil, Or Not To Olive Oil?

Something that struck me in my surveying of various pizza dough recipes is that there’s no consensus about the inclusion of olive oil. Jamie Oliver says we should include it, Heston says we shouldn’t. Hugh Fearnley-Whittingstall says we should, Felicity Cloake says we shouldn’t. Delia says we should, the Associazione Verace Pizza Napoletana not only says we shouldn’t, but that they’ll come round our houses and shout at us if we even attempt it. I have half a mind to exclude HFW’s opinion because he thinks putting kale on a pizza is acceptable – but if we overlook that, the basic head-count is level at three-all. Sarah, the originator of the recipe I’ve been using, didn’t include olive oil, though that may have been because of an admirable desire to keep the recipe simple. So in our quest to make better pizza, there is an obvious first question: would our pizzas be better if we included olive oil? There’s only one way to find out!*

[*There are in fact many ways to find this out. But the one I chose was to do an experiment.]

Kale munchers

Kale gives you bright eyes and a glossy coat

Experimental dough:                                                   Standard dough:
500g strong white flour                                                500g strong white flour
325g water                                                                   325g water
7g instant yeast                                                            7g instant yeast
10g salt                                                                        10g salt
20g olive oil                                                                  [No olive oil]

The doughs were made up by hand and each kneaded for five minutes. They were then covered and left to prove for two hours. For this experiment, there were three means of assessing the difference between the doughs:

1. The Pizza Test: two pizzas were made with dough, tomato sauce and mozzarella, and baked at 250C for 14 minutes. They were then tasted side by side. Given that this project is about pizza, this seems the most important test – if there’s no detectable difference here, then the difference between doughs probably isn’t worth worrying about. However, tomato sauce and mozzarella on their own are pretty tasty, so just eating pizza on its own may not allow us to notice more subtle differences in the dough itself. For that reason, we also ran…

2. The Flatbread Test, which you might also call the “untopped pizza test”. Dough was rolled out and baked until it was lightly golden in colour. This allows for a comparison of the two doughs, without any interference from the flavour of the toppings. However, only having two tests seems somehow less complicated than it could be. If we’re really obsessing about the trivial minutiae of making pizza, we might as well push the boat out. It is for that reason alone that we included…

3. The Dough Ball Test: for each dough we made a dough ball weighing 50g, and left this to prove for 20 minutes, before baking it until lightly golden. Having a larger, rounder mass of dough allows us to study any differences in how the dough rises, as well as giving a better sense of how the crumb structure of the two doughs compare. Also, I like dough balls, and this way I get to eat two. It’s win-win.


Eyeball test: perhaps surprisingly, the doughs looked almost identical. I had assumed the dough with the oil would look visibly more yellow. But that wasn’t the case. It did have a smell of olive oil, which I would probably attribute to the olive oil I’d put in it. But visually, there was little difference.

Olive oil pizza, left, and standard pizza, right

Olive oil pizza, left, and standard pizza, right

Pizza test: there were two differences that were noticeable in the pizzas themselves. The first was that the crust of the olive oil dough was softer, whereas the standard pizza had more of a crunch to it. The second difference – and in terms of shock value, this is right up there with news about where bears defaecate – was that the pizza with olive oil tasted a little bit of olive oil. It wasn’t a very strong taste, and compared to the taste of the toppings, it didn’t really stand out. But it was there, and it was pleasant enough. The texture differences were more pronounced. Both pizzas were good, and I’d have been happy to eat either. Indeed, to demonstrate that point, I ate both, in the name of science. But the differences between the doughs were relatively small: I had a very slight preference for the flavour of the olive oil dough, and a slight preference for the texture of the standard dough.

Flatbread test: without any toppings to distract from the sheer, brazen misery of eating dry pizza base, the taste difference between the doughs was more apparent. The taste of olive oil came through more strongly than with the comparison of pizzas. Visually, there were no obvious differences between the two doughs, and texture was similar – both were crisp. If I was really forced to choose one flatbread over the other, I would probably cry, and wonder why someone was forcing me to make such a miserable choice. The only thing worse than eating dry pizza base is eating dry pizza base with kale.

Dough ball test: this was interesting: when shaped into tiny boules, the difference between the dough was accentuated. The two dough balls looked identical, but felt noticeably different. The olive oil dough ball had a softer outer crust in comparison to the standard dough ball, which felt firmer and more crisp. Both had very similar crumb structure, but the mouthfeel of the olive oil dough ball was less satisfying and less well-defined – the crust disappeared into the crumb when I ate it. In contrast, there was a nice and more distinct mix of crunch and softness with the standard dough ball. If I had to make dough balls, I’d go for the standard dough. I would also include a lot of garlic butter. And lots of wine as an accompaniment. That’ll basically be what my retirement will look like. Dough balls, garlic and booze.

The Verdict:

The Verdict

Our experimental question was “Should we include olive oil in our pizza dough recipe?”. From this experiment, it seems that adding olive oil to the standard dough recipe imparts extra flavour. This is pleasant but quite subtle, and could potentially get lost entirely in any pizza with strongly flavoured toppings. However, olive oil also seems to reduce the crunch of the crust, and makes for a softer bake. That changes the experience of eating the pizza, and gives it a more homogenous mouthfeel – there’s less noticeable difference between the dough in the middle and the dough at the edge. I like the crunch that the standard dough has, and think that the extra flavour of the oil in the dough doesn’t compensate enough for the loss of texture. So, with this recipe at least, the verdict is a no to olive oil. If you decide you really like the taste of olive oil, you can always drizzle some on at the end. Mmmm.

The Basic Recipe

All experiments need a point of comparison, to provide a context for whatever effect our manipulation might have. This is best illustrated by considering pharmacological studies. If I, for example, chomped down a fistful of LSD and then stormed onto the stage of Strictly Come Dancing to attempt an audacious Viennese waltz, an observer witnessing the ensuing shambles might conclude that taking LSD makes me a terrible dancer. But unless they’ve seen how I dance normally (that is, my dancing baseline), they can’t really tell what about my dancing is to do with the effects of the drug, and what’s just my own God-given talent. In that case, they’ve just made an assumption. And it’s a well-known fact that when you “ass-ume”, you make a real tit of yourself.

For this blog, I’ll be using the following recipe for the baseline pizza – all changes will be variations around this procedure. It’s a simple recipe that just uses the four basic pizza ingredients: flour, water, salt and yeast. The recipe was passed on to me by my friend Sarah, though when she showed me how to make it, the quantities involved were less precise (the original amounts are shown in brackets – it’s almost as if Sarah thinks making pizza is not something worth obsessing over minutely. Ha!) We may also infer that Sarah thinks that adding olive oil to pizza dough is for effete buffoons (for more on that topic, see Experiment One).

Control group

Control-group pizza:

  • 500g strong white flour (“some flour”)
  • 325g water (“a mug of water”)
  • 7g instant yeast (“a sachet of yeast”)
  • 10g salt (“some salt if you want”)

Sift together the flour, yeast and salt. Add the water, and mix to a dough. I usually start with a wooden spoon, and as the dough comes together, I switch to mixing by hand. Knead for about five minutes. Leave to rise in a warm place for 2 hours, then separate the dough into thirds, and roll each into a pizza shape. Top as you wish, and bake at 250 degrees centigrade for 12 minutes, or until the crust is golden brown.

The unexamined life is not worth living

So wrote Socrates. Inexplicably, his thoughts on pizza are not recorded. But he almost certainly took the same view about pizza as he did about life: the unexamined pizza is not worth eating. On this blog, I’ll be taking a leaf out of Socrates’s book, by systematically studying the different factors that go into making pizza. I’ll report a series of experiments conducted in my state-of-the-art food laboratory, designed to refine and improve pizza making, one step at a time. Each experiment will involve the manipulation of a single factor – be it an ingredient or a procedure – in two batches of pizza. These pizzas will be identical, apart from the single factor the experiment is investigating. In other words, with all other things being equal. It’s good scientific practice, and it’s also an extremely twee name for the blog.