Il faut bien pétrir la pâte pour qu’elle ne se casse pas.

No. In il faut, il does not mean he. It is an impersonal subject, like it in English it is necessary.

Il faut is a very common French expression meaning:

• it is necessary
• you must
• one must

So Il faut bien pétrir la pâte... means something like You have to knead the dough properly...

This structure is fixed:

• Il faut + infinitive = it is necessary to ...
• Il faut pétrir = you must knead

Because after il faut, French often uses an infinitive.

Pattern:

• Il faut + infinitive

Examples:

• Il faut attendre. = You must wait.
• Il faut travailler. = You have to work.
• Il faut bien pétrir la pâte. = You must knead the dough well.

If you want to say someone specific must do something, French often uses:

• Il faut que + subject + verb

For example:

• Il faut que tu pétrisses la pâte. = You must knead the dough.

So in your sentence, the infinitive is used because the statement is general and impersonal.

Yes, here bien means well, properly, or thoroughly.

So:

• bien pétrir = to knead well / properly

In many contexts, bien does not just mean in a good way. It can also add the idea of enough, properly, or thoroughly.

Here, it suggests that the dough needs to be kneaded sufficiently so that the next result happens: it does not break.

Pétrir means to knead, especially dough.

It is a cooking and baking verb. You use it for working dough with your hands or with a machine.

Related words:

• la pâte = dough
• pétrir la pâte = to knead the dough

So this is very natural baking vocabulary.

Because here French is talking about the dough involved in the recipe or situation, not some dough in a general quantity sense.

Compare:

• Je fais de la pâte. = I am making some dough.
• Il faut pétrir la pâte. = You must knead the dough.

French often uses the definite article le / la / les when talking about something already understood from the context, even where English might sometimes be less explicit.

In a recipe or instruction, la pâte is very natural because it means the dough you are working with.

Because pour que is used when it is followed by a new subject and a conjugated verb.

In your sentence:

• pour que introduces a clause
• the clause has its own subject: elle
• and its own verb: se casse

So:

• pour
  • infinitive
• pour que
  • subject + conjugated verb

Compare:

• Il faut pétrir la pâte pour réussir la recette.
  Here the subject stays the same, so French uses pour + infinitive.
• Il faut bien pétrir la pâte pour qu’elle ne se casse pas.
  Here there is a separate clause, so French uses pour que.

Also, pour que usually expresses purpose: so that, in order that.

Because pour que normally requires the subjunctive in French.

So after pour que, you usually get:

• pour que + subject + subjunctive

The verb here is se casser, and the subjunctive form for elle is:

• qu’elle se casse

This looks the same as the present indicative for this verb, which can be confusing. But grammatically, it is still the subjunctive because it comes after pour que.

Another example:

• Je parle doucement pour qu’il dorme. = I speak softly so that he can sleep.

So even if the form does not always look special, the mood is still important.

Se casser means to break in an intransitive/reflexive sense: to break, to snap, to come apart.

Compare:

• casser quelque chose = to break something
• se casser = to break / to get broken itself

In your sentence:

• la pâte is not breaking something else
• the dough itself is breaking / tearing / cracking

That is why French uses se casser.

Here elle refers to la pâte, and se refers back to that same thing:

• pour qu’elle ne se casse pas = so that it doesn’t break

In French, with a conjugated pronominal verb, the negative usually wraps around the verb, and the reflexive pronoun stays directly before the verb.

Pattern:

• subject + ne + reflexive pronoun + verb + pas

So:

• elle ne se casse pas

Breakdown:

• elle = subject
• ne ... pas = negation
• se = reflexive pronoun
• casse = verb

Other examples:

• Il ne se lave pas. = He doesn’t wash himself.
• La porte ne se ferme pas. = The door doesn’t close.

So the word order is normal for a negative pronominal verb.

Qu’elle is a contraction of que elle.

French avoids the vowel clash between que and elle, so que becomes qu’ before a vowel sound.

So:

• pour que elle... becomes pour qu’elle...

This is very common:

• qu’il
• qu’elle
• qu’on
• qu’ils

The apostrophe is required in normal written French.

Elle refers to la pâte.

Since pâte is a feminine noun in French, the pronoun used to refer back to it is elle.

So:

• la pâte → elle

This is grammatical gender, not biological gender. English uses it for things, but French uses il or elle depending on the noun’s gender.

That would mean something different.

• pour ne pas casser la pâte = so as not to break the dough
• pour qu’elle ne se casse pas = so that it does not break

The first version focuses on someone not breaking the dough. The original sentence focuses on the dough itself not breaking.

So the original is better if the idea is that good kneading helps the dough stay elastic and not tear or crack.

A natural pronunciation is roughly:

Il faut bien pétrir la pâte pour qu’elle ne se casse pas.

Helpful pronunciation notes:

• Il faut sounds roughly like eel fo
• bien has a nasal vowel, something like byan but nasalized
• pétrir sounds roughly pay-treer
• pâte sounds like paht
• pour qu’elle links smoothly; qu’elle sounds roughly kel
• ne is often weak in speech, and in casual spoken French it may even be dropped, though it stays in standard writing:
  • written: qu’elle ne se casse pas
  • casual speech: qu’elle se casse pas

A rough full approximation:

• Eel fo byan pay-treer la paht poor kel nuh suh kass pa

But of course, French sounds cannot be matched exactly to English spelling.