Cuando hace calor, me gusta beber gazpacho bien frío.

In Spanish, weather expressions often use hacer:

• hace calor = it’s hot / it’s warm
• hace frío = it’s cold
• hace sol = it’s sunny
• hace viento = it’s windy

So hacer calor is a fixed, very common way to talk about hot weather.

• es calor is not used for weather.
• está caliente means something is physically hot, like La sopa está caliente.

So in this sentence, Cuando hace calor is the natural way to say when it’s hot.

Because this sentence describes a general situation or habit:

• Cuando hace calor, me gusta beber gazpacho bien frío.
• When it’s hot, I like to drink gazpacho very cold.

Spanish uses the present tense here because it means whenever it’s hot or in hot weather.

This is different from a specific future situation. For example:

• Cuando haga calor, beberé gazpacho.
  = When it’s hot / when hot weather comes, I’ll drink gazpacho.

So:

• cuando + present = general/habitual situation
• cuando + subjunctive = future or not-yet-realized situation

Because gustar works differently from to like in English.

A helpful way to think of it is:

• me gusta beber gazpacho
  = drinking gazpacho is pleasing to me

So:

• me = to me
• gusta = is pleasing

That is why Spanish uses an indirect object pronoun like me, te, le, etc.

Examples:

• Me gusta el café. = I like coffee.
• Te gusta nadar. = You like swimming.
• Nos gusta viajar. = We like travelling.

So gusto by itself would mean I please or would belong to a different structure, not the usual way to say I like.

Because the thing that is grammatically doing the pleasing is the infinitive phrase beber gazpacho bien frío.

In Spanish, an infinitive often behaves like a singular idea, so it takes gusta:

• Me gusta comer temprano.
• Me gusta leer.
• Me gusta beber gazpacho bien frío.

You use gustan when the thing liked is plural:

• Me gustan los libros.
• Me gustan las sopas frías.

So here, the subject is the action beber gazpacho bien frío, treated as singular, which is why gusta is correct.

Yes, in Spain you could also say tomar gazpacho.

Both are possible, but there is a small nuance:

• beber focuses specifically on drinking
• tomar is more general and very common for food and drink consumption in Spanish

Since gazpacho is a cold soup that people often drink from a glass or bowl, beber gazpacho sounds natural. But tomar gazpacho is also extremely normal.

So:

• beber gazpacho = to drink gazpacho
• tomar gazpacho = to have / take gazpacho

In Spain, tomar is especially common in everyday speech.

Because here gazpacho is being used in a general, non-specific way.

Spanish often omits the article with food and drink after verbs like comer, beber, tomar, especially when talking about consuming something in general:

• Me gusta beber agua.
• Quiero comer pizza.
• Suelo tomar café por la mañana.

So beber gazpacho means to drink gazpacho in a general sense.

If you add the article, it often sounds more specific:

• Me gusta beber el gazpacho que hace mi abuela.
  = I like drinking the gazpacho my grandmother makes.

So in this sentence, no article is perfectly natural.

Here bien is an intensifier. It means something like:

• nicely cold
• really cold
• good and cold

So gazpacho bien frío means the gazpacho is served very cold, which is especially natural in Spain.

You could also say muy frío, and that would be correct too. The difference is mainly tone:

• muy frío = straightforward, neutral very cold
• bien frío = very natural, slightly more expressive, often used in everyday speech

Examples:

• una cerveza bien fría
• agua bien fresca
• servirlo bien caliente

So bien frío is idiomatic and common.

Because frío agrees with gazpacho, and gazpacho is a masculine singular noun.

Agreement in Spanish means adjectives usually match the noun in:

• gender: masculine/feminine
• number: singular/plural

So:

• el gazpacho frío
• la sopa fría
• los gazpachos fríos
• las sopas frías

Since gazpacho is masculine singular, frío must also be masculine singular.

Because in Spanish, descriptive adjectives usually come after the noun.

So:

• gazpacho frío
• agua fría
• cerveza fría

This is the normal position when you are simply describing the noun.

Putting the adjective before the noun can sometimes happen in Spanish, but it often changes the tone or sounds literary, emphatic, or less natural in everyday speech. In this sentence, gazpacho bien frío is the standard and natural order.

Because the sentence begins with a subordinate clause:

• Cuando hace calor, ...

When this kind of clause comes first, Spanish normally uses a comma before the main clause:

• Cuando tengo tiempo, leo.
• Si llueve, no salimos.
• Aunque es tarde, sigo trabajando.

If the main clause comes first, the comma is often omitted:

• Me gusta beber gazpacho bien frío cuando hace calor.

So the comma here is standard and correct.

Because here cuando is a conjunction meaning when.

In Spanish:

• cuando = no accent, used in normal statements
• cuándo = with an accent, used in direct or indirect questions, or exclamations

Compare:

• Cuando hace calor, bebo gazpacho.
• ¿Cuándo hace más calor en Sevilla?

So in your sentence, it is not a question word. It is simply introducing a clause, so cuando has no accent.