Lesson 6 of 14 · Settings · 3 minutes
Instructions vs messages
Everything you send to an oven is one of two kinds of text. Knowing the difference is the single best trick for better answers.
Two kinds of text
- Instructions (the "system prompt") are house rules that last for the whole chat: who the oven should be, how long its answers are, what it must never do. Think of the recipe card pinned above the counter.
- Messages (the "user prompt") are what you type each time: the actual question or job, like an order slip.
Every bakerbaker is mostly a well-written set of instructions, which GrannyBakes builds for you from the wizard's answers.
Before and after
Here is the same message baked on the same oven, without and with instructions:
The message My sponge cake sank in the middle. What went wrong?
Same oven, same message. Only the instructions changed.
Without instructions
The oven decides how to answerA sponge cake usually sinks because its center hasn’t set firmly enough to support the cake as it cools. Common causes include:
- Underbaking: The edges look done, but the middle is still wet. Bake until the center springs back lightly and a tester comes out clean.
- Oven temperature problems: An oven that’s too cool can leave the center unset; opening the door early can make the cake collapse. Preheat fully and avoid opening the oven until it’s nearly done.
- Foam losing air: Sponge cakes rely on whipped eggs for lift. Under-whipping—or knocking out the air while folding in flour—can weaken the structure. Fold gently, just until combined.
- Too much raising agent or liquid: Incorrect measurements can make the cake rise quickly, then collapse. Measure carefully and follow the recipe’s pan size.
- Cooling too abruptly: Some sponge cakes need to cool gradually, or even upside down. Follow the recipe’s cooling instructions.
If it sank while baking, check the oven temperature and avoid opening the door. If it sank after coming out, underbaking or abrupt cooling is especially likely.
5.2 s · 18 in / 331 out tokens · 91 of them thinking · $0.00017
With instructions
Granny's house rules on topInstructions sent
You are Granny, a warm home baker. Answer in at most three short bullet points in plain words, then add one encouraging sentence.
- It may have needed a little more time in the oven; the middle sank if it wasn’t fully set.
- Opening the oven door too early can make the cake lose its lift.
- Too much baking powder or beating the batter after adding flour can weaken it.
It happens to every baker—your next sponge can still be lovely!
2.5 s · 49 in / 137 out tokens · 63 of them thinking · $0.000073
Without instructions the oven wrote a long, thorough guide. With two sentences of house rules it gave a short, friendly answer, and it was cheaper too, because the answer was shorter.
Good instructions
- Say who the oven is: "You are the friendly assistant of a family bakery."
- Say what to do and how long: "Answer in three sentences."
- Give rules in plain words: "Never promise delivery dates."
- Add an example of a good answer if you have one.
Keep instructions short and clear. A page of rules costs input tokens on every message.
Text or a form
Normally the oven answers in text. You can also ask for JSON, a fill-in form with fixed boxes like "name", "date" and "total". That's useful when another step of a recipe has to read the answer.
Granny's rule of thumb: put what never changes in the instructions and what changes in the message.