I got an interesting comment from a student in my Orgasmic Vegetables class. Yup, that’s
really the name of the class. He said that he tried roasting butternut squash using my
video (that’s before he took a class) and it never had a nicely browned stage the way
the video showed. It was pale for a long time and then turned black. Any ideas as to what
might have caused this problem?
I use a lot of oil when I roast veggies. I mean, at least a ¼ cup for a half sheet and
for some vegetables like roasted cabbage wedges even more. When that student saw me roasting
the veggies in class, he was shocked. I use just as much oil in my videos and I give explicit
measurements for them, but I am guessing most people think they can reduce the oil without
compromising the results. I have gotten every possible reaction in my veggies class when
people watch me with the olive oil bottle. I’ve had jaws dropping. I’ve had people
whispering helpful advice to each other along the lines of “you really don’t need that
much oil. I roast my veggies with just 1 tablespoon”. Look, to each their own. But this got me thinking.
What exactly happens when you use less and less oil? So I set up a little experiment.
I cut up a crazy amount of butternut squash and roasted it with 4 different amounts of
oil. Here are the basics of my experimental set up. For each test, I used 600 grams of
squash on a quarter sheet sprinkled with 2.5 grams of salt. The oven temperature was set
to 400F which was probably closer to 425F because my oven runs hot, but it was the same
for all the cookie sheets. Each cookie sheet went into the oven all alone, so that the
positioning in the oven was the same. For 600 grams of squash, I normally use 28 grams
of oil, so for this experiment, I did it with 7, 14, 21, and 28 grams.
As a proper scientific experiment, this was a complete failure for a few reasons. Every
piece on a cookie sheet browns differently. The center browns the least and the outside
browns the most, so doing any fair comparison of color was very difficult. There was even
a difference between the outer pieces. Some were darker than others. So how would you
make sure that you are comparing apples to apples? I don’t know. It was also hard to
show you in the video the textural differences. It’s not just how dark the pieces are. It’s
whether they are developing sticky, caramely sort of browning or charred sort of browning.
Then there was the problem of when to stir them. Do I stir them when they achieved the
kind of browning I like? Or do I stir them all at the same time.
So, after trying this, I realized that I don’t know how to set up a proper experiment for
this to give you good quantitative data, but it’s hard to spend the entire day roasting
squash and not learn something, so here is what I’ve learned... and keep in mind that
this is somewhat subjective.
There wasn’t much difference between 21 and 28 grams of oil. Both were delicious and
both produced slightly sticky, nicely caramelized browning. Even 14 grams of oil wasn’t too
bad. But more pieces tasted a little burnt vs caramelized. And with only 7 grams pretty
much all browning tasted either wimpy or burnt.
A very interesting thing for me was how exactly do you apply this oil. Normally, I put the
veggies on the baking sheet and drizzle them with oil and toss them right on the sheet.
But for this experiment, I used a bowl to toss the veggies before pouring them onto
a baking dish. I think that’s how you are supposed to do it, but I never do. If you
are very generous with oil, it’s not that hard to distribute it evenly. But the less
oil you use, the harder it is to spread it out over every surface of every piece. And
that’s where the bowl comes in. It helps you give your veggies a good toss. That’s
probably why 14 grams of oil was better than I expected. My problem with the bowl is that
I don’t want to wash it and some veggies like big pieces of cabbage will fall apart
if you try to toss them. But there are many cases where a bowl would help, so if you are
reducing the oil in any of my recipes, at least use a bowl and don’t go lower than
2-3 Tbsp per half sheet. In case you are wondering, I would use 4.
Another thing to keep in mind is that not all vegetables will react the same way to
the reduction of oil because some have more sugars, some have more water, so there is
no one amount that will work for everything. Because you can’t ruin vegetables with too
much oil, but you can easily ruin them with not enough oil, I just go to town with it.
If you want to try my kind of roasted vegetables, here is how to develop your intuition for
how much oil to use. Don’t worry, we are not going to dirty any measuring spoons or
cups or create any extra dishes for you to wash. Take the cap off your olive oil bottle.
Set the bottle on the scale and press the tare button to get to zero. Pour some oil
all over your veggies and put the bottle back on the scale. Keep doing that until you get
to -56 grams for a half sheet. By volume, that’s a quarter cup and that’s how much
oil I’d use. I know most of you think you don’t need it, but try it once and see if
you like the results. Depending on how many veggies you have on the cookie sheet, and
depending on the vegetable type, some of this oil might not be absorbed after you are done
roasting. If that happens, tilt the cookie sheet for the excess oil to drip out. You
could refrigerate this leftover oil and reuse it.
I am sure a question will come up about which oil I use. I use cheap extra virgin olive
oil. The exact brand varies, but at the moment it’s 365 brand from whole foods. This one
is supposedly Spanish. But they sell them from greece, portugal, italy, etc. I haven’t
tried them all. But out of the ones I have tried, Spanish was my favorite. I don’t
like very aggressive or bitter oils. So I like this one because it’s mild, but you
can use anything you want. I tried using non extra virgin oil for roasting and the veggies
had less flavor, so I do prefer extra virgin. But I also don’t use my finest oil for this.
I think it would be a waste of money on a cooked dish. Save that for your salads or
other dishes where the oil won’t be heated.
May your oil flow freely and may your vegetables be delicious.
Here are more thought provoking videos for you to check out and if you are ever in the
Boston area, maybe I’ll see you in one of my classes.