grammar - Why 次第 instead of によって in this very example?

I was randomly browsing this page and came across this sentence:

砂糖{さとう}は作｛つく｝るものしだいで使用｛しよう｝します。

This recipe happens to have a French equivalent

• En fonction des recettes, on utilise du sucre.


• Depending to recipes, we use sugar. (literal translation)


• In some recipes we may use sugar. (A little more glossed)

so I can say for sure what was the intended meaning.

But, what bothers me is that I have always been told that 次第で（は） is always followed by something that will change -- generally an increase/decrease, or a decision/choice. But here I have the feeling that 使用します is neither a choice or a decision it is merely a prescription: the recipe tells you to do that.

I think that the sentence can be rewritten (with minor changes in meaning) to:

砂糖は作るもの/料理によって、使用されます。

My question is the following:

• Are によって and 次第で interchangeable in this context?


• If yes what is the most natural option?


• Is there any difference between しだいで and 次第で, the former seeming a little softer and childish (if at all I can consider しだい as childish)?

Answer

Q1: Is there any difference between しだいで and 次第で, the former seeming a little softer and childish (if at all I can consider しだい as childish)?

Sometimes writing in kanji is called 閉じる and writing in hiragana is called 開く. There are no strict official rules on how to write something in kanji or in kana. This decision is difficult even for native speakers so there are several guides about this written by editors.
But, there are some tendencies, and it is possible to change how readers feel. With a lot of kanji, a document would become official and hard.

Grammatically, しだい has two types: a noun and a suffix. In general, a noun tends to be written in kanji, and a suffix tends to be written in hiragana.

事の次第

金しだい

But, as I said, this is not a strict rule, and you may choose either.
At least, it does not look childish in this case.

Q2: Are によって and 次第で interchangeable in this context?

Before that, I would like to explain the difference between によって and によっては.

Well, I talked with a few natives, and they agreed, but I only found a few Chinese sites explaining this. http://www.360doc.com/content/13/0704/17/6753995_297640602.shtml

国によって生活習慣が違う。(Each country has its own customs.)

In this case, all countries are different in their own way. This means "Depending on."

国によっては豚肉を食べない。(There are some countries whose people do not eat pork.)

In this case, the other countries are the same. This means "Only in a certain condition."

So, if I say,

国によっては生活習慣が違う。

it implies some countries have different customs (, but others are the same).

So, to me,

砂糖は作るものによって、使用されます。

sounds a little bit strange.

砂糖は作るものによっては、使用されます。

sounds good because there are only two options: to use or not to use.

To me, 次第で can be used in both two meanings above.

砂糖は作るもの次第で使用します。

If there are a lot of options, it is natural to use によって.

砂糖は作るものによって、量が変わります。(The amount of sugar to use depends on what to make.)

砂糖は作るものによっては、量が変わります。(In some cases, the amount of sugar to use may change.)

These are interchangeable with examples below respectively.

砂糖は作るもの次第で、量が変わります。

砂糖は作るもの次第では、量が変わります。

(At least, to me.)

Q3: 使用します or 使用されます。

I think these three are all grammatically ok.

砂糖は料理に使用します。

砂糖を料理に使用します。

砂糖は料理に使用されます。