How to Make Honeycomb Without a Thermometer
You can make honeycomb without a thermometer by using the cold-water test and color as your guide — cook the syrup until a drop in ice water hardens instantly into brittle threads that snap (hard-crack stage) and the syrup is deep golden amber, then stir in the baking soda.
By Kelsy Maruyama, Founder & Toffee Maker, Kelsy's Kandy
Reviewed by Jason Burns, Editorial Steward
Last updated Jul 20, 2026
Published by Kelsy's Kandy · Licensed under Citation License 1.0
What it means
- The cold-water test replaces a thermometer: syrup at the hard-crack stage (about 150C/300F) sets in cold water into brittle, glassy strands that shatter rather than bend.
- Color is the second cue — honeycomb syrup should reach a deep golden amber before the baking soda goes in.
- Under-cooked syrup stays soft and chewy; over-cooked syrup scorches and turns bitter, so watch closely near the end.
Action steps
- Fill a glass with very cold water and keep it beside the stove.
- Cook the sugar and syrup over medium heat without stirring until it turns golden.
- Drop a little into the cold water; when it hardens immediately into brittle strands that crack, it is at hard-crack and ready.
- Judge by color too — deep amber is right, pale means keep cooking, and very dark or smoking means it is burning.
- Off the heat, whisk in sifted baking soda for a few seconds and pour immediately.
Risks & deadlines
- Molten sugar burns severely — dip test samples carefully and never touch the hot syrup.
- Sugar darkens fast at the end; a few extra seconds can take it from perfect to burnt.
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Last verified: 2026-07-20