Candy Making Calculator

Water boils at a lower temperature at higher altitudes (about 1°F less per 500 feet above sea level). Since candy temperature is tied to the concentration of sugar in water — not to an absolute temperature — you must reduce your target thermometer reading proportionally. Without this adjustment, your candy will be over-concentrated and too firm for its intended stage.

Corn syrup (glucose syrup) is an invert sugar — it contains glucose and fructose molecules that interrupt the formation of sucrose crystals during cooling. Adding corn syrup to hard candy keeps it glassy and clear instead of grainy or white. It is not essential for crystalline candies like fudge (where controlled crystallization is the goal) but is critical for clear, glass-like hard candies.

Yes — a fast-reading digital probe thermometer works better than traditional glass candy thermometers, which can be slow to respond and difficult to read. Calibrate your thermometer in boiling water first and adjust your target by the difference from 212°F (or your altitude-adjusted boiling point). Digital thermometers accurate to ±1°F are sufficient for candy making.

Grainy fudge is the result of uncontrolled crystallization — large sugar crystals forming instead of many small ones. Causes include: stirring too early (before the fudge cools to about 110°F), undissolved sugar crystals on the pan sides seeding the mixture, or insufficient beating once the correct temperature is reached. Beat fudge vigorously as soon as it reaches 110°F and continue until it thickens and loses its gloss.

Use a heavy-bottomed saucepan at least 3 times the volume of your ingredients (sugar syrup can triple in volume when boiling). A straight-sided pan makes it easier to monitor the boiling surface evenly. Heavy copper or thick stainless steel provides the most consistent heat distribution. Avoid non-stick pans — the high temperatures required for hard crack stage can damage non-stick coatings.

Hygroscopicity (moisture absorption) is the main cause of sticky hard candy. Wrap pieces individually in cellophane or waxed paper immediately after they cool and store in an airtight container with silica gel packets. Avoid making hard candy on humid days (above 60% relative humidity), as even small amounts of absorbed moisture will cause it to become tacky within hours.

Yes — add concentrated candy flavoring (oil-based, not water-based) and gel food coloring after removing the pan from heat and just before pouring. Use oil-based flavorings because the boiling temperatures involved would evaporate water-based extracts. Add approximately 1 teaspoon of flavoring per 250g of sugar. Stir quickly, pour immediately, as the candy sets fast.

Both work, but through different mechanisms. Cream of tartar (potassium bitartrate) inverts some sucrose into glucose and fructose during cooking, inhibiting crystallization. Use about 1/4 teaspoon per cup of sugar. Corn syrup adds pre-formed glucose directly. Corn syrup is more predictable and is preferred for clear hard candies; cream of tartar is traditional in British toffee recipes.

Hardened sugar dissolves easily in hot water. Fill the pot with water and bring to a boil — the sugar residue will dissolve completely within minutes. Do not try to scrape hardened candy from pots while dry; you risk scratching the surface and the effort is unnecessary. Candy-coated thermometers should be soaked in hot water before scrubbing.