The Cold Water Test is a way to test the stages of sugar, which is indicated by the harness of the sugar when dropped into a cup of cold water. A very long time ago, I used the same test in the kitchen, not because I didn't have a candy thermometer available, but I didn't have enough of the them. When you are making several things all at once, or when you are staging several batches of whatever needs hard sugar, knowing what the sugar syrups look and feel like at their respective stages is very important.
The Cold Water Test Chart
Begin with a boiled sugar syrup. Gather a 2 cup clear glass liquid measure (such as Pyrex) and fill it half way with cold water. Not iced water, just cold water. Pour a teaspoon of the hot syrup into the cup of water and pick up the resulting sugar ball in the water. The table below tells you the approximate temperature reached by the look of the ball. You will notice as the sugar boils, it produces a thicker product with a darker color, too, as it cooks and continues to cook.
- Soft Ball Stage - 236°F - 238°F
You'll get a soft ball that you can lift from the water.
- Medium Soft Ball Stage - 238°F - 240°F
You'll get a soft ball that you can actually hold its shape for about a half a minute before losing it.
- Firm Ball Stage - 242°F - 245°F
You'll get an actual firm ball of sugar that will hold it's shape for several minutes.
- Hard Ball Stage - 245°F - 254°F
You'll get a hard, stiff ball that can be pressed and molded with your fingers.
- Light Crack - 264°F - 270°F
You'll get a ball or clump of sugar that is hard enough to clink on the rim.
- Medium Crack - 270°F - 280°F
When the sugar is dropped from a spoon into the cold water will actually thread in the water, and is very hard and strong.
- Hard Crack - 282°F - 290°F
This produces the hardest sugar clump in the water, but it is also the most brittle.
Image above of a candy thermometer in sugar syrup is credited to Lindsay Hickman via Wikimedia Commons through a Creative Commons License.
Renee Shelton, Creator of PastrySampler.com