Stories from the Lab: Rotavap—Coolest Machine Ever!
Fresh off the gelatin-making experience described in my last blog post, I was excited to move on to some more amazing experiments in the culinary science program at the CIA! This time, my classmates and I got to make chocolate truffles infused with a flavor extract of our choice. Even better: to extract these flavors, we got to use a rotary evaporator!
Have you ever heard of a rotary evaporator? Flavor development is essential to food creation, and with the rotary evaporator—rotavap for short—you can extract concentrates from the aroma of foods, including oils, purées, sauces, juices, and other materials. You literally can evaporate, distill, purify, and separate any liquid you please.
The rotary evaporator was first created in 1950 by Lyman C. Craig, but was commercialized for industrial use by the Swiss company Buchi in 1957. Rotary evaporators are most often utilized by chefs for molecular gastronomy techniques. Chef Grant Achatz used it to extract herb aromas like basil for use in his restaurants, and a Switzerland native, Chef Mario Waldispühl, used it to reach the boiling point of tomato sauce faster compared to traditional cooking methods. However, rotary evaporators can also be used in pharmaceutical and chemical laboratories.
Time to Start the Rotavapping
Let me tell you, using the rotavap was COOL! My partner, Paige, and I decided to do two flavorings—purple hibiscus flowers and blackberry purée.
Here’s how it works:
- Paige and I had to first dilute the substances with water to make it a loose liquid. Then we transferred it to a flask that we connected to the machine.
- We then filled the bin underneath the flash with lukewarm water. This flask will then rotate in the water at any chosen RPM or speed.
- A vacuum pump was connected to the rotary evaporator to reduce atmospheric pressure, allowing liquids to move to a vapor phase at low temperatures.
- That vapor is then condensed by coils cooled by a recirculating chiller and collected in a receiving flask. (It comes out clear!)
After we made the extracts, we added them to the mixtures for our chocolate truffles. Some other extracts that my classmates created were sriracha and figs. When tasting the truffles, we found that they were hard and crunchy, but the extracts gave them an interesting taste that you wouldn’t expect.
Working with the rotary evaporator was one of my favorite labs this semester. This is exactly the type of device that professional culinary scientists— especially flavorists and chemists—would use in the field or a lab when developing products. I can’t wait to do more culinary science experiments with the coolest cooking equipment on campus. Next up is cheesemaking!
- Stories from the Lab: The Grand Finale—My Senior Thesis Project! - October 3, 2019
- Stories from the Lab: Discovering Kimchi—and Some New Ingredients Too! - September 9, 2019
- Stories from the Lab: Sausage Making – The Right Stuff - August 26, 2019