Across:
1 Serves up (= reversal indicator) the foreign (LA = -AL) beer (brew) endlessly (w) (‘brew’ without ‘w’ = bre = -ERB-) from the very start (‘very’ start = V-) (VERBAL) of speech (VERBAL),
4 Well-to-do (AFFLUENT) retiring (= reversal indicator) foreign footballers (FA = AF-) can be eloquent in a manner of speaking (-FLUENT) (AFFLUENT),
9 Holds the distinction (NICETY) of being taken in by Venice tycoon (held by ‘Venice tycoon’ = NICETY),
10 Reproduce (SIMULATE) Muesli (Muesli = SIMUL-E) mix (= anagram indicator) containing first of the almonds (first of the ‘almonds’ =-A-) and last of the fruit (last of the ‘fruit’ = -T-) (SIMULATE),
12 Sharp-eyed type (OBSERVANT) bravest on (bravest on = OBSERVANT) manoeuvres (= anagram indicator),
13 Outfit (DRESS) finishes with 18 across (finishes ‘evening dress’ = DRESS),
14 Foundations at the base presumably (HOLDS THE FORT) does the job of those higher up, temporarily (HOLDS THE FORT),
18 Designs (= anagram indicator) V-engine (V-engine = EVENING) for mini (DRESS) (EVENING DRESS) with a little black number (EVENING DRESS),
21 Drug dealer (pusher) loses head (p) (‘pusher’ without ‘p’ = USHER) with escort (USHER),
22 Little doubt (SUSPICION) cousin’s (cousins = SUS-CION) plan (= anagram indicator) includes setting up (= reversal indicator) address (IP address = -PI-) (SUSPICION),
24 Adrian is (Adrian is = SARDINIA) out (= anagram indicator) in the Mediterranean (SARDINIA),
25 Humiliates absent Thai (‘humiliates’ absent ‘Thai’ = umlies = MUESLI) put out for breakfast (MUESLI),
26 Spots (RASH-) half a Guinness (half a ‘Guinness’ = -NESS) (RASHNESS) – what would you expect from a tearaway? (RASHNESS),
27 Briefly (d) study (‘read’ without ‘d’ = REA-) issue (issue/offspring = -SON) (REASON) with some common sense (REASON).
Down:
1 Vehicle (VAN) for Rocky (= anagram indicator) Hogg’s (hoggs = GOGHS) (VAN GOGHS) famous paintings (VAN GOGHS),
2 The Stones (rocks = ROCK S-) on key (-ALT key on keyboard) (ROCK SALT) coming out of The Cellar (ROCK SALT from the salt cellar),
3 Include autodidact, originally (include ‘autodidact originally’ = ACTOR) a man of many parts (ACTOR),
5 Knock off early (FAIL TO FINISH) and leave the books with no end in sight (FAIL TO FINISH),
6 Cleaned up (LAUNDERED) three articles from three countries (la + une + der = LAUNDER-) using blue pencil (editor = -ED) (LAUNDERED),
7 Thrilled (ELATED) by story (tale = ELAT-) set up (= reversal indicator) by writer (-ED) (ELATED),
8 Takes cues from sheet music (takes ‘cues’ from ‘sheet music’ = hemsi = THEISM) and belief in the creator (THEISM),
11 Graduate (BA-) to object (object/item = -THING) to those in the pack (SUITS in pack of cards) (BATHING SUITS) offering beach outfits (BATHING SUITS),
15 Sign (S-IGN) over (-OVER-) English (-E-) house (SOVEREIGN) produced with old money (SOVEREIGN),
16 First person (-I-) from America (-US-) consumed by character builders (genes = GEN-ES) (GENIUSES) among the wise guys (GENIUSES),
17 A (A-) star (-SUN-) from club (-C-) is charged (-ION) (ASUNCION) in South American capital (capital of Paraguay is ASUNCION),
19 Cavalryman (HUSSAR) takes Moll out in the small hours (takes ‘Moll’ out in ‘small hours’ = sahurs = HUSSAR),
20 Part of the rap (CHORUS) or such (or such = CHORUS) rubbish (= anagram indicator),
23 Engaged (IN USE) to Sue in (sue in = IN USE) production (= anagram indicator).