La salsa queda mejor con albahaca fresca que con tomillo.

Here quedar does not mean just to stay or to remain.

In this sentence, quedar mejor means something like:

• to turn out better
• to be better
• to work better
• to taste better / suit it better in context

So La salsa queda mejor con albahaca fresca... means that the sauce comes out better or is better with fresh basil.

This use of quedar is very common when talking about how something looks, fits, works, or turns out:

• Te queda bien esa camisa. = That shirt looks good on you.
• Así queda mejor. = It’s better that way / It looks better that way.

Because quedar adds the idea of result or how something turns out.

Compare:

• La salsa es mejor con albahaca fresca.
  = The sauce is better with fresh basil.
  This is understandable, but more neutral or general.

• La salsa queda mejor con albahaca fresca.
  = The sauce turns out better / comes out better with fresh basil.
  This sounds more natural when talking about the effect of using one ingredient rather than another.

So quedar mejor often suggests: if you make it this way, the final result is better.

Because salsa is a feminine singular noun in Spanish.

So it takes:

• la = the
• feminine adjectives if needed

Examples:

• la salsa
• una salsa
• la salsa italiana

A learner might be tempted to think nouns ending in -a are always feminine, and while that is often true, it is still something you learn noun by noun. In this case, salsa is indeed feminine.

Because fresca agrees with albahaca, and albahaca is feminine singular.

So:

• albahaca = feminine singular
• fresca = feminine singular adjective

Agreement in Spanish is very important:

• tomillo fresco = fresh thyme
• albahaca fresca = fresh basil

The adjective usually changes to match the noun in gender and number.

Because after con, Spanish often uses a noun without an article when talking about an ingredient or material in a general sense.

So:

• con albahaca fresca
• con tomillo

means with fresh basil / with thyme, not with the fresh basil / with the thyme.

This is very natural in Spanish when talking about ingredients, especially in recipes or general statements:

• Prefiero el té con limón.
• La pasta queda bien con queso.
• Se hace con harina y agua.

If you said con la albahaca fresca, it would usually sound more specific, as if you meant with the fresh basil we’re talking about.

Because in Spanish, comparisons of superiority are normally made with:

• más ... que = more ... than
• mejor ... que = better ... than
• peor ... que = worse ... than

So:

• mejor con albahaca fresca que con tomillo
  = better with fresh basil than with thyme

This is the normal comparison structure.

Examples:

• Es mejor así que de otra manera.
• Queda mejor en azul que en rojo.

A common mistake for English speakers is trying to overcomplicate this. Here, que is exactly the word you want after mejor.

Because Spanish often repeats the preposition in comparisons for clarity and balance:

• con albahaca fresca que con tomillo

This is the most natural structure here.

You might think of it as:

• better with fresh basil than with thyme

Repeating con makes the two options line up neatly:

• con albahaca fresca
• con tomillo

That parallel structure is very common and sounds best.

Because grammatically fresca only modifies albahaca here.

So the sentence literally compares:

• with fresh basil
• with thyme

It does not automatically mean with fresh basil than with fresh thyme.

If the speaker wanted to say both herbs are fresh, they would usually make that explicit, for example:

• La salsa queda mejor con albahaca fresca que con tomillo fresco.

In real life, sometimes context makes it obvious, but grammatically the adjective only belongs to the noun it is attached to.

Yes, you could, and people would understand it. But the nuance is a little different.

• está mejor = is better
• queda mejor = turns out better / works better / comes out better

In cooking contexts, queda mejor often sounds especially natural because it focuses on the result of preparation.

So:

• La salsa está mejor con albahaca fresca
  sounds fine.

• La salsa queda mejor con albahaca fresca
  often sounds a bit more idiomatic when discussing how the dish comes out.

Most likely taste, but quedar mejor can be broader than that.

Depending on context, it can mean:

• tastes better
• works better
• turns out better
• is better overall

With food, listeners will usually understand it as something like the sauce is better / tastes better with fresh basil than with thyme.

Spanish often leaves that slightly open instead of specifying sabe mejor (tastes better).

Yes, but the original order is very natural.

The standard version is:

• La salsa queda mejor con albahaca fresca que con tomillo.

You could also hear variations for emphasis, but they are less neutral:

• Con albahaca fresca, la salsa queda mejor que con tomillo.

That version puts more focus on con albahaca fresca.

For a learner, the original sentence is the best model to remember.

Yes. Albahaca is still a feminine noun even when there is no article.

You can see that from the adjective:

• albahaca fresca

If it were masculine, it would be fresco.

So even without la, the noun’s gender is still there and still affects agreement.

Yes. This sounds natural in Spain.

The structure X queda mejor con Y que con Z is very normal in everyday Spanish, especially when talking about:

• food
• clothes
• decoration
• style
• combinations of things

Examples:

• El pollo queda mejor con limón que con naranja.
• Ese color queda mejor con negro que con marrón.

So this sentence is a very useful pattern to learn.