A thermometer takes much of the guesswork...

A thermometer takes much of the guesswork out of candy-making. But if you don’t have one and you get a sudden urge to make a batch of peanut brittle or fudge, you’ll probably be able to turn out a pretty good product using the old-fashioned cold water method of testing.

In the simplest terms, candies are made by boiling sugar and water together over moderate heat. The temperature the syrup reaches and the amount of water that evaporates determine the texture of the finished candy.

For fondant, fudge and panocha, the syrup is cooked to 234-240 degrees. They turn out firm, but since they retain some moisture, they are soft enough to bite easily. When made well, they have a velvety smooth texture.

Candies cooked to higher temperatures range from chewy to very brittle. Examples are caramels, divinity, taffy, toffee, brittles and glaces.

Both types should be made in a heavy pan with straight sides and a flat aluminum bottom. Aluminum provides the most uniform heat distribution, which means the candy is less likely to burn. The pan also needs to be at least four times larger than the combined ingredients so that they can boil rapidly without spilling over the top.

The rate of heating is another important part of candy-making. Keep the mixture boiling at a moderate, steady level over the entire surface. The temperature will rise slowly to about 220 degrees. After that, it rises quite quickly.

Water for the testing should be cold but not icy. Use fresh water and a clean spoon for each test.

Remove the pan from the heat while testing. At the higher temperatures, even a few more seconds over heat may be enough for the mixture to move to the next stage.

Humid days are the trickiest time to make candy without using a thermometer. Moisture in the air is absorbed by the candy as it cools, causing some candies to turn out too soft.

To compensate, cook the candies to a temperature about two degrees higher than you would on dry days. This is difficult to do without a thermometer, so if you’re going to make candy even a few times a year in a humid climate, it’s probably worth investing in this equipment.

Check the accuracy of the thermometer each time you use it by immersing it in boiling water about 10 minutes. If the reading varies from the correct figure for the boiling point (212 degrees), add or subtract the difference when judging the temperature called for in the recipe.

When not using a thermometer, work quickly to test the mixture. Dip the spoon, then let a few drops fall into the cold water and use your fingers to check the firmness. If the syrup hasn’t reached the correct stage, continue testing every two to three minutes.

A few other things to keep in mind when making candy:

* Measure ingredients carefully.

* Follow recipe directions to the letter. Don’t even try doubling or halving a recipe; it can result in subtle differences in cooking temperature, leading to failed candy. Unless you’ve got a lot of experience, candy-making, unlike many other kinds of cooking, is not an interpretive art.

* Candy-making takes place at temperatures well above the boiling point, so don’t use a metal spoon for stirring. A long-handled wooden spoon will remain cool.

* Stir the candy mixture until the sugar dissolves.

* Be careful to wash down or steam off any sugar crystals from the sides of the pan, as directed in your recipe. Crystals can interfere with the proper development of the syrup.

* Pour out the finished mixture, but do not scrape the pan.