Die Röstzeit beeinflusst den Geschmack der Röstung.

These are different cases:

• die Röstzeit = nominative feminine singular, the subject of the sentence
• den Geschmack = accusative masculine singular, the direct object
• der Röstung = genitive feminine singular, showing of the roast / of the roasting

So the structure is:

• Die Röstzeit = the roasting time
• beeinflusst = influences
• den Geschmack = the flavor
• der Röstung = of the roast

A very literal breakdown is: The roasting time influences the flavor of the roast.

In this sentence, the verb is beeinflusst, and the thing doing the influencing is die Röstzeit. That makes it the subject.

Also, its article is die, which here is nominative feminine singular. That is another clue.

So:

• Die Röstzeit = what causes the action
• den Geschmack der Röstung = what is affected by the action

Because the subject die Röstzeit is third person singular.

The infinitive is beeinflussen = to influence.

Present tense:

• ich beeinflusse
• du beeinflusst
• er/sie/es beeinflusst
• wir beeinflussen
• ihr beeinflusst
• sie/Sie beeinflussen

Since die Röstzeit is grammatically like sie = it/she, the correct form is beeinflusst.

Because German very often forms compound nouns by joining words together.

Here:

• Röst- comes from rösten = to roast
• Zeit = time

So Röstzeit means roasting time.

English often uses separate words, but German usually combines them into one noun:

• Kaffeehaus = coffee house
• Backzeit = baking time
• Röstgrad = roast level

This is one of the most important patterns in German vocabulary.

They are related, but they are different word types:

• rösten = a verb: to roast
• die Röstung = a noun: the roasting / the roast
• die Röstzeit = a noun: the roasting time

So:

• rösten describes the action
• Röstung names the process or result
• Röstzeit names the duration of that process

This kind of word family is very common in German.

Because after Geschmack in this sentence, Röstung is in the genitive case.

Base form:

• die Röstung = nominative

Genitive singular feminine:

• der Röstung

So der Röstung means of the roast / of the roasting.

Compare:

• die Farbe der Bohnen = the color of the beans
• der Geschmack der Röstung = the flavor of the roast

For feminine nouns, the article changes from die to der in the genitive.

Yes, you could sometimes hear or say something like:

• der Geschmack von der Röstung

But in this kind of formal or written style, the genitive is more natural and more elegant:

• der Geschmack der Röstung

So for learners, this sentence is a good example of a standard written German pattern:

• noun + noun in the genitive

No, this is very normal German word order for a main clause:

Subject + verb + object

• Die Röstzeit = subject
• beeinflusst = verb
• den Geschmack der Röstung = object

German main clauses usually put the finite verb in second position. Since the subject comes first here, the sentence looks quite similar to English.

Because Geschmack is masculine: der Geschmack.

When a masculine noun is a direct object, its article changes in the accusative:

• nominative: der Geschmack
• accusative: den Geschmack

That is why the sentence has den Geschmack.

This is a very important pattern:

• der → den for masculine accusative singular

Example:

• Der Kaffee hat einen starken Geschmack.
• Die Röstzeit beeinflusst den Geschmack.

The ö is a front rounded vowel that English does not really have as a standard sound.

A rough approximation:

• Say something like eh as in bed
• While doing that, round your lips as if saying oo

So:

• rösten
• Röstzeit
• Röstung

The Röst- part is related in all of them, so learning the pronunciation once helps with the whole word family.

Yes, that can help.

German often uses a genitive noun phrase where English might use:

• of ...
• or a noun used adjectivally

So:

• der Geschmack der Röstung literally = the flavor of the roast
• in smoother English, you might think of it as the roast flavor or the flavor produced by roasting, depending on context

But grammatically in German, it is still:

• main noun: Geschmack
• genitive phrase: der Röstung

Here it feels more like a process/result noun, depending on context.

die Röstung can refer to:

• the roasting process
• a particular roast
• sometimes the roast profile/result

In this sentence, der Geschmack der Röstung suggests the flavor associated with the roast or roasting process, not necessarily one physical object.

German often uses such nouns flexibly, and the exact nuance depends on the topic. In a coffee context, this sounds very natural.