Is the expression "the biggest such business" grammatically correct?

Question

I have found the expression “the biggest such business” in the second sentence in The Economist.

It has also made it easier for people to find the ingredients, kit and talent necessary to cook them up illegally. For years the biggest such business was making stimulants such as amphetamines and methamphetamines, which are also produced in neighbouring countries (see article).

The Economist

So I tried to find out in what order to use ”such“ and ”a superlative.“ and I have finally found the following.

You can't follow "such" with a superlative.

Word Reference

Does this mean "such the biggest business" is incorrect?

Both statements are confusing. Which is a grammatically correct expression?

Answer 1

In answer to the headline question: yes, it's grammatically correct.

Determiner

You're confusing two different uses of such. There's a good summary of usage here:

• such (Collins English Dictionary):

The very first definition for the word (scroll down on that page) is also the meaning used by The Economist in the original post.

1. a. of the sort specified or understood (such books shouldn't be sold here)

In this use, such is not forming a superlative, but acting as a determiner: here, it states that the noun it attaches to ("businesses") is the same one that was already discussed in a previous sentence.

Placing the adjective

There's no special rule for placing an adjective near "such". If in doubt, replace it with "of this kind of", and place the adjective using that structure instead.

• the biggest such business
• the biggest of this kind of business

such ... that for superlatives

What you uncovered was the rule for creating superlatives using "such", but in this case, the phrase that "such" precedes is always followed by 'that', as in the two same-meaning sentences below:

• It was such hard work that we were sore for days afterwards.
• The work was very hard, and as a result we were sore for days afterwards.