Learn Hardcore Turkish: Pilavı yapmadan önce pirinçleri iyice yıkamıştım. - I had washed the rice thoroughly before making the pilaf.

-madan önce means “before doing …”. It’s built by attaching the negative converb suffix -ma/-me plus the ablative -dan/-den to the verb stem, then adding önce (“before”). Despite the name “negative converb,” it doesn’t make the clause negative here—it simply marks a temporal clause:
• Yuvarlanmadan önce pijamalarınızı giyin. – “Put on your pajamas before rolling (in the snow).”
• Pilavı yapmadan önce pirinçleri iyice yıkamıştım.

Why is the direct object pilavı in the accusative case instead of just pilav?

In Turkish, a direct object that is definite or specific takes the accusative suffix -ı/-i/-u/-ü. Here you’re talking about the pilav you intend to make, so you mark it pilavı. If you speak in general, no suffix is needed:
• Pilav yapmak zor değil. – “Making pilaf isn’t hard.”

Why do we see pirinçleri with a plural -ler and accusative -i?

Although pirinç (“rice”) is a mass noun, speakers often pluralize it (pirinçler) to emphasize the individual grains or a specific batch. Then, because it’s a definite object here, you add the accusative -i, giving pirinçleri (“the rice grains”/“the rice”). You could also say pirinci (“the rice”) without pluralizing; the nuance is slight.

Why is the verb yıkamıştım in the past perfect tense (-mıştı) rather than the simple past (-dı)?

-mıştı marks the past perfect, indicating an action completed before another past action. Here, “washing” was finished before “making the pilav.” The subordinate clause pilavı yapmadan önce already sets the sequence, so you could say pirinçleri iyice yıkadım, but using yıkamıştım emphasizes that the washing was fully done prior to cooking. Compare:
• Trene binmeden önce biletimi almıştım. – “I had bought my ticket before boarding the train.”

What is iyice, and how is it formed from iyi?

iyice is an adverb meaning “thoroughly” or “well.” It’s formed by adding the adverbial suffix -ce/-ça to the adjective root iyi (“good”). This suffix turns adjectives into manner‐adverbs:
• güzel → güzelce (“nicely”)
• yavaş → yavaşça (“slowly”)
• iyi → iyice (“thoroughly”)

Why does the sentence use pilavı yapmadan önce instead of pilavı pişirmeden önce?

Turkish has set collocations for making certain dishes. With pilav, the normal verb is yapmak (“to make”), not pişirmek (“to cook”). Therefore you say pilav yapmak, much like salata yapmak (“make salad”), çay yapmak (“make tea”). Although pilavı pişirmeden önce isn’t ungrammatical, it sounds less idiomatic.

Can you rearrange the clauses? For example, put pilavı yapmadan önce at the end?

Yes, Turkish word order is flexible. You could say:
• Pirinçleri iyice yıkamıştım pilavı yapmadan önce.
But the most natural order is to lead with the time clause: Pilavı yapmadan önce pirinçleri iyice yıkamıştım. The usual pattern is [Time/Condition] + [Main Clause] for clarity.