Monthly Archives: January 2011

Surprise! The mystery seeds from last week were grape seeds (Vitus).

These were peeled from a red grape purchased at the grocery store.

These days many of the grapes in the store are seedless. How are seedless grapes grown and can you grow grapes from seeds?

Seedless grapes and many other varieties of grapes are grown these days by planting cuttings. Each year the vines are trimmed back so they will produce more fruit. The pieces of vine can be used for cuttings to start new vines.

It is possible, however, to grow grapes from seeds. There are several species of grapes that aren't in commercial production and grow naturally from seeds. (See more about growing grapes from seeds in the experiment section below).

One species of wild grape found in the Southwest is the canyon grape, Vitus arizonica.

The fruit of the canyon grape (Photograph by Stan Shebs  from Wikimedia)

Other wild grapes include Vitis californica, Vitis cinerea var. helleri and Vitis girdiana.

Grapes of various species are grown throughout the world for fruit (table grapes), raisins, juice and wine.

Even the leaves are used for wrappers for cooking food in.

This gnarly grape was growing at a winery in the Napa Valley of California. As a vine, usually grapes are grown with some sort of support, but these trunks were so large on these that they no longer needed wires or posts to stand up.

Ready for some science using grapes?

Here are some ideas and links to get you started.

1. First of all, how do you grow grapes from seeds?

Like many other plants, grapes require a cold period before they will germinate. Most websites suggest putting the seeds in a baggy in the fridge for at least 30 days. Also, the rate of germination is often not very high, so start with a lot of seeds. has an article to help get you started

2. Ever wonder how grapes get their color? Interested in genetics?

Here's an interesting article on Jumping genes and the color of grapes
(click in at the foot of the page)

3. Want to look more into how raisins are made?

Here are some raisin FAQ's and raisin trivia from the National Raisin Company

And then try your own grape dehydrating experiment

4. Now use those raisins to make raisin divers.

Drop raisins into a carbonated beverage, and see what happens.

This video shows the results, but has some flaws. First of all "lemonade" is actually a lemon-based soda. Any carbonated beverage would work, but clear lets you see the raisins better. Also, the raisins are not changing buoyancy, but are acting as an place for the carbon dioxide bubbles to aggregate, rise and release.

5. Some of the science behind fermentation

Using yeasts to ferment grape sugar

6. How many seeds in different types of fruit?

7. You may have used cabbage juice as a pH indicator, but grape juice smells better and can be used straight from the jar.

Grape Juice as a pH indicator

Use your grape juice indicator to create art

8. Did you spill your grape juice indicator? Let's clean up. But what cleaner to use?

Here's a experiment to find the best grape juice stain remover

Do grapes grow where you live? What is your favorite food using grapes?


Have you heard about the Google Science Fair yet?

Who: Students interested in science between the ages of 13 – 18, including home schooled students

What: Complete a science fair project, set up a Google Sites website to display your results, and submit it to the Google Science Fair competition

When: Between January 11, 2011 and April 4, 2011.

This video will give you an overview of what you need to do to participate:

I highly recommend that you carefully read the rules before starting any project. Most science fairs have strict rules, especially about projects featuring humans and other vertebrates, so be sure you read and understand the restrictions.

For ideas for projects try the links below or click on the "experiment list" button above:

Janice VanCleaves Play and Learn About Science:  Science Project Ideas for Kids

Science Buddies Science Fair projects

Science Fair Central

List of Student Projects at The University of Arizona

Neuroscience For Kids


The Google site also has links to science resources

Good luck and be sure to let me know if you have any questions.