Kelsy's Kandy

Why Add Baking Soda to English Toffee?

Baking soda is added to English toffee to release tiny carbon-dioxide bubbles that lighten and aerate the hot candy, giving it a more tender, easy-to-bite texture that breaks cleanly instead of setting into a dense, tooth-cracking slab.

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

  • When the alkaline baking soda hits the hot, slightly acidic sugar it fizzes, foaming carbon dioxide through the toffee.
  • Those microscopic bubbles create a lighter, more porous structure that snaps and eats more easily than solid hard candy.
  • The alkalinity also nudges browning (Maillard/caramel) reactions along, deepening color and flavor slightly.
  • It is used in small amounts — typically well under a teaspoon — since too much tastes soapy.

Risks & deadlines

  • Add it off or at the end of cooking and stir quickly — the mixture foams up dramatically and can overflow a small pan.
  • Too much baking soda leaves a soapy, metallic aftertaste, so measure carefully.

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Last verified: 2026-07-20