Kitchen Chemistry Glossary
Short, accurate definitions -- no more than the site can actually back up with a real explanation. Every term links to the article section where it's covered in full.
This grows alongside the site's pillars and articles, not ahead of them -- a term appears here once there's a real mechanism behind it to link to. Where a definition is accurate but the full deep-dive article isn't written yet, the term is flagged "fuller article coming" instead of being padded out early.
A
Acid
What baking soda needs to react with to release CO₂ -- buttermilk, brown sugar, cocoa, and yogurt are common recipe acids. See in Leavening →
B
Boiling point elevation
The real reason candy thermometers work: dissolved sugar raises water's boiling point, so temperature becomes a stand-in for concentration. See in Sugar Work →
C
Caramelization
The thermal breakdown of sugar on its own under heat, no protein required -- a different reaction from Maillard browning, even though both produce color and flavor. See in Heat & Transformation →
Coagulation
Proteins unfolding and permanently linking together under heat, turning a liquid egg into a solid one. See in Eggs →
Creaming (method)
Beating fat and sugar together so sugar's sharp crystal edges cut air pockets into the fat -- a mechanical form of leavening, not just mixing. See in Fats & Dairy →
Crystallization
Sugar molecules locking into a repeating lattice -- desirable in fudge's fine grain, unwanted when it turns a syrup grainy. See in Sugar Work →
E
Emulsion
Oil droplets held suspended in water by an emulsifier like lecithin, instead of separating -- the mechanism behind mayonnaise and hollandaise. See in Eggs →
F
Fermentation
Yeast metabolizing sugars and releasing CO₂ as a byproduct -- a living process, not a chemical reaction, which is why it's slow and temperature-sensitive. See in Leavening →
Freezing point depression
Dissolved sugar or salt lowering water's freezing point below 0°C -- the same colligative-property family as boiling point elevation, running in reverse. See in Cold & Freezing →
G
Gluten
The stretchy, cross-linked protein network formed when wheat proteins (glutenin and gliadin) are hydrated and worked -- what gives bread its chew and its ability to trap gas. See in Structure →
H
Hydration
The ratio of water to flour by weight -- one of the two main levers controlling how much gluten a dough develops. See in Structure →
Hydrocolloid
A long-chain molecule (xanthan gum, guar gum) that thickens water into a gel-like network -- used to stand in for gluten's structure in gluten-free baking. See in Substitutions & Alternatives →
Hygroscopicity
A substance's tendency to absorb moisture from the surrounding air -- the reason hard candy turns sticky in humid storage. See the full article →
I
Inversion (sugar)
Heat and acid splitting some sucrose into glucose and fructose -- the resulting invert sugar physically interferes with crystal formation. See in Sugar Work →
M
Maillard reaction
The browning reaction between proteins and reducing sugars under heat -- distinct from caramelization, and sped up by higher pH. See in Heat & Transformation →
Meringue / egg foam
Egg white proteins unfolded by mechanical force (whipping) rather than heat, linking up around air bubbles to trap them. See in Eggs →
O
Ostwald ripening
Larger crystals slowly growing at the expense of smaller ones whenever a system experiences slight melting and re-freezing -- the real mechanism behind ice cream turning icy in storage. See the full article →
P
Plasticity (fat)
The narrow temperature range where a solid fat is soft enough to trap air but firm enough to hold its shape -- roughly 13–18°C for butter. See in Fats & Dairy →
Polymorphism (fat)
A fat's ability to solidify into multiple different crystal structures with different melting points and textures -- the reason chocolate and butter both need to be worked into one specific structure on purpose. See in Chocolate & Cocoa →
R
Retrogradation
Gelatinized starch slowly re-crystallizing as it cools, squeezing out moisture and firming the crumb over time -- the real mechanism behind bread going stale, distinct from simply drying out. See the full article →
S
Saponin
A naturally occurring surfactant molecule -- found in aquafaba, where it stabilizes an egg-white-like foam despite sharing no relation to egg protein. See in Substitutions & Alternatives →
Starch gelatinization
Starch granules absorbing water and swelling as they heat past roughly 60–70°C, stiffening a baked good's crumb alongside gluten. See the full article →
Syneresis
A protein or gel network slowly squeezing out liquid it was holding, once stretched or stressed past its limit -- the mechanism behind a weeping meringue. See the full article →
T
Tempering
Whisking hot liquid into eggs gradually so proteins coagulate slowly and evenly, instead of curdling from a sudden temperature jump. See in Eggs →