Baking science
The processes underneath everything else, with what is settled separated from what is not.
Start here if you want one idea
Why baking fails
A small number of mechanisms account for most of what goes wrong, and they turn up again and again under different names. Knowing the five means recognising a fault you have never seen before.
Every concept here states its evidence tier and, separately, what is not settled about it. That second field is mandatory and “nothing material” is not an acceptable answer — a site that explains gluten and kitchen folklore in the same confident register has taught its readers nothing about how to weigh a claim.
Proteins
Gluten is the famous one and it is not the only one. Egg protein sets, milk protein browns, and the gluten-free question is really a question about which proteins can be asked to do which job.
Gluten development
The formation of an elastic protein network from wheat’s glutenin and gliadin when flour is hydrated and worked.
Established scienceProtein coagulation
The irreversible setting of egg and gluten proteins on heating, which is what stops a rising bake from rising further.
Established scienceStructure without gluten
Gluten does four separable jobs. A gluten-free bake has to rebuild each of them from different materials, and which one is missing decides what went wrong.
Established scienceMechanical dough development
Building a gluten network with energy instead of time — the principle behind the Chorleywood Bread Process and most of the bread sold in Britain.
Professional consensusWhat makes a flour strong
Protein percentage is the number on the packet and it is not the whole answer — composition, milling and damaged starch all move the result.
Established science
Starch
The most abundant thing in most bakes and the least discussed. It absorbs water, swells, sets a crumb on the way up and then slowly undoes that on the way down.
Starch gelatinisation
The irreversible swelling and disruption of starch granules when heated with enough water, which is what sets a baked crumb.
Established science
Sugars
Sugar is a structural ingredient that happens to taste sweet. It competes for water, lowers the temperature at which things set, and browns.
Maillard reaction
A family of reactions between reducing sugars and amino groups that generates most of a crust’s colour and savoury complexity.
Established science
Fats
Solid, liquid or somewhere in between, and the somewhere-in-between is where almost all baking behaviour lives — creaming, lamination and shortness are all the same property seen three ways.
Fat plasticity and crystal structure
Why the same fat behaves differently at different temperatures, and why what a fat can do is a property of its state rather than of its name.
Established science
Gas, and holding on to it
Making bubbles and keeping bubbles are separate problems solved by separate ingredients. Confusing the two is why a gluten-free loaf rises and then collapses.
Leavening
The four distinct routes by which gas gets into a bake, and the fact that all of them expand existing cells rather than creating new ones.
Professional consensus
Heat
An oven does not heat a bake evenly and never has. What actually reaches the crumb, how fast, and from which direction explains more faults than any recipe variable.
Heat transfer in an oven
Four mechanisms act at once and they are not interchangeable — which is why the same setting bakes differently on a different shelf, in a different tin, in a different oven.
Established science
Water
Present in everything, free in very little of it. How much water a formula contains and how much of it can still reach the flour are different numbers.
Hydrocolloids and viscosity
How gums and soluble fibres take up water, build viscosity and hold gas — and why each of them does it differently enough that they are not interchangeable.
Established science
Fermentation
Living populations rather than an ingredient, which is why fermentation is judged by observation and not by a clock.
Fermentation
The metabolism of sugars by yeast and bacteria into carbon dioxide, alcohol, acids and a large share of bread’s flavour.
Established science
Staling and storage
Bread does not go stale by drying out, and treating it as though it does is why so much of the standard storage advice makes things worse.
Starch retrogradation and staling
The gradual re-ordering of gelatinised starch as a bake cools and ages, which is what staling mostly is.
Established scienceMoisture migration
Water moving within a bake and out of it — the second staling mechanism, and the one that explains why a crust softens while the crumb firms.
Professional consensus
Where to go next
See it go wrong
Every diagnosis here names the mechanism underneath it, so a fault is a worked example of the science rather than a separate subject.
Which ingredient does which job
The same mechanisms, approached from the packet rather than from the process.
How we know
The register behind every tier on this page, including what was read, what could not be obtained, and what a source turned out not to support.