Ketchup and xanthan gum

In my desire to spend some more time doing funky cooking, I bought a little bag of xanthan gum.  I’ve been thinking about making a sauce or gravy with it.  Reading this little ketchup article (thanks Hairpin!) tied the ‘two-finger-tap’ to my new food additive.

One interesting fact about ketchup that everyone should know is that it’s a non-Newtonian fluid. Naturally, ketchup is rather thin and watery, because the tomato pulp that gives it consistency is sieved out. As a result, commercial ketchup makers add a small amount of xanthan gum to their ketchup recipes to thicken it. But this ingredient has another side effect: It turns ketchup into a shear thinning fluid. In other words, how quickly ketchup flows depends upon the stress that is being placed upon it.

via How 500 Years Of Weird Condiment History Designed The Heinz Ketchup Bottle | Co.Design: business + innovation + design.

That ketchup is non-Newtonian is the main reason why getting it out of a glass bottle is so slow. Allowed to flow naturally, ketchup only travels at a speed of 147 feet per hour. The only way to speed it up is to apply force, which through the principle of shear thinning decreases the ketchup’s viscosity, and thus increases its flow rate. This is why you have to thump a bottle of ketchup to get it flowing from the bottle. The concussive force makes it flow faster.

But despite common opinion, the bottom of a bottle of Heinz Ketchup isn’t actually the best place to thump it. If you apply force to the bottom of a bottle of Heinz, the ketchup closest to where you smacked will absorb most of the force of impact. It will flow freely, but the ketchup that is viscously clogging the neck and mouth of the bottle won’t, leaving you no better off than you were before. The solution is to trigger the shear thinning effect at the top of the bottle, not the bottom. That unclogs the mouth and lets the ketchup below to freely flow.

So while the substance of Heinz’s “57 Varieties” label may be just a fanciful whim on the part of the company’s creator, its positioning is deliberate. It’s a target. By simply tapping the label with two fingers, you create the optimal conditions for shear thinning, transforming non-Newtonian ketchup into a free-flowing liquid. Physics!

via How 500 Years Of Weird Condiment History Designed The Heinz Ketchup Bottle | Co.Design: business + innovation + design.

Advertisements

2 Comments

Filed under cultural appropriation, food, health, learning, science

2 responses to “Ketchup and xanthan gum

  1. We use xanthan gum all the time in the food industry…if you make your own dips, salad dressings, or cole slaw, adding a little gum to the mix will help stop the ‘watering out’ (syneresis) from occurring.

    • Thanks chef. I like the idea of playing with xanthan gum. I’m thinking about thickening a bunch of my favorite sauces — maybe to keep during the work week. I’m going to play with recreating veganaise, goddess dressing, and a few other things. Besides I ought to be making all my own condiments.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s