Author Topic: On the relative density of root vegetables  (Read 2934 times)

Wowbagger

  • Stout dipper
    • Stuff mostly about weather
On the relative density of root vegetables
« on: 06 April, 2017, 08:18:07 pm »
The humble root vegetable has, for reasons (hopefully) lost in the mists of time, been given a special place in the heart (or wherever...) of this forum. But recent culinary escapades have led me to what I think is beginning to become a conclusion: raw parsnips float but sink when they are cooked whereas with carrots, the opposite is true.

I first noticed this when using a slow cooker, where there was lots of fluid and the veg were floating free. When in the confines of a saucepan there is generally not enough space for them to swap places, as it were.

Has anyone else witnessed this phenomnomnomenon?
Quote from: Dez
It doesn’t matter where you start. Just start.

hellymedic

  • Just do it!
Re: On the relative density of root vegetables
« Reply #1 on: 06 April, 2017, 08:32:36 pm »
I have always presumed floaty parsnips contained air that was replaced by water on cooking. The sugar and starch they contain makes them denser than water.
Carrots, being less starchy, lose some of their soluble sugar on boiling so making the stew/soup denser whilst themselves losing density.
You could vary the salt/sugar content of your soup/stew to change vegetables' flotation...
... but ICnBA!

Cudzoziemiec

  • Ride adventurously and stop for a brew.
Re: On the relative density of root vegetables
« Reply #2 on: 06 April, 2017, 08:58:08 pm »
Curious. I had not noticed that. Raw potatoes don't float but I have a feeling boiled ones might. Or do they? We (that means you, Wowbagger) need to do a comparison test with turnips, swedes, sweet potatoes, celery root, beetroot, radish, daikon, horseradish, etc etc and publish the results here. With photos of course.
Riding a concrete path through the nebulous and chaotic future.

ElyDave

  • Royal and Ancient Polar Bear Society member 263583
Re: On the relative density of root vegetables
« Reply #3 on: 06 April, 2017, 11:05:39 pm »
of course you can't just look at boiling either.

Does a parsnip become more or less floaty if roasted? Or a stir fried carrot? Or what about the humble chip, more or less floaty than a roasty, or a boiled newby?

So many degrees of freedom, I feel the need for a paper in some journal somewhere
“Procrastination is the thief of time, collar him.” –Charles Dickens

Re: On the relative density of root vegetables
« Reply #4 on: 07 April, 2017, 08:23:10 am »
I've always found it fascinating that olive pits sink.

They are woody (nearly all wood has a density less than water) and contain quite a bit of oil (oils are less dense than water). But olive pits sink in fresh water.
Weird
<i>Marmite slave</i>