Fabulous fun.
Thanks to Goliath for a most enjoyable challenge. This setter can be quite tricksy at times, but I found this very accessible, but still a satisfying solve.

ACROSS
1. Perhaps New Zealander and South American will take hint by the first of October (10)
ANTIPODEAN
ANDEAN (South American) will take TIP (hint) by O[ctober] (first of)
6. Finally cross bench and heave (4)
SPEW
[cros]S (finally) + PEW (bench)
9. Assorted mixture of island folk (2,3,5)
OF ALL KINDS
(ISLAND FOLK)* (*mixture of)
10. Designer uniform clothing could be a snare (4)
DRUM
D[esigne]R U[nifor]M (clothing)
A snare is one type of drum, hence ‘could be’
12. Consequence concerning 10s (12)
REPERCUSSION
RE (concerning) + PERCUSSION (10s, referring to 10 across and note the S for plural)
15. Ghetto in Spain, both short of food (9)
SPAGHETTI
GHETT[o] (short) in SPAI[n] (short), i.e. both short
17. Like gardens to be lopsided (5)
ASKEW
AS (like) + KEW (gardens)
18. Getting into taxi always pivotal (5)
AXIAL
[t]AXI AL[ways] (getting into)
19. Syndicates regularly employed so-and- so to disrupt aortic treatment (9)
CONSORTIA
[s]O-[a]N[d]-S[o] (regularly employed) to disrupt AORTIC* (*treatment)
20. Not far from Mick Jagger’s perhaps extraordinary worth (1,6,5)
A STONE’S THROW
A STONE’S (Mick Jagger’s, perhaps) + WORTH* (*extraordinary)
24. Country’s intelligence captures central laboratory (4)
IRAQ
IQ (intelligence, intelligence quotient) captures [labo]RA[tory] (central)
25. Most important and complete part of Yorkshire (10)
OVERRIDING
OVER (complete) + RIDING (part of Yorkshire)
26. Want to be heard, do some baking! (4)
NEED
“KNEAD” (do some baking, “to be heard”)
27. It’s no problem coming in puffed up and under the influence (10)
HYPNOTISED
(IT’S NO)* (*problem) coming in HYPED (puffed up)
DOWN
1. Excited to enter synagogue (4)
AGOG
2. Wood frames for the artwork (4)
TEAK
T[h]E A[rtwor]K (frames for)
3. Lonely type, he recycled plastic (12)
POLYETHYLENE
(LONELY TYPE HE)* (*recycled)
4. Doctor and author has energy (5)
DRIVE
DR (doctor) and I’VE (author has)
5. Extra cover for Charlie’s habit (9)
ADDICTION
ADDITION (extra) cover for C (Charlie)
7. Each prison disturbed yet particular (10)
PERNICKETY
PER (each) + NICK (prison) + YET* (*disturbed)
8. Ladies curse their garments (10)
WOMENSWEAR
WOMEN (ladies) + SWEAR (curse)
11. Key justifier is one getting out of a bind (12)
ESCAPOLOGIST
ESC (key) + APOLOGIST (justifier)
13. Rise of criminal case circle in American region (10)
ESCALATION
CASE* (*criminal) + O (circle) in LATIN (American region)
14. Publication by creative artist beginning to exasperate judge (10)
MAGISTRATE
MAG (publication) by ARTIST* (*creative) + E[xasperate] (beginning to)
16. Around 55, losing cash yet computer literate (4-5)
TECH-SAVVY
Around V V (5 5), (CASH YET)* (*losing)
21. Wading bird caught by another one (5)
HERON
[anot]HER ON[e] (caught by)
22. Pine for young woman (4)
MISS
23. Old impressionist briefly made a comeback (4)
AGED
DEGA[s]< (impressionist, briefly, <making a comeback)
Yes great fun! Liked repercussion, Iraq, polyethylene, womenswear, many others. Thanks both.
A playful and breezy puzzle from Goliath with some very witty cluing, as always. Liked REPERCUSSION (like James), ASKEW, PERNICKETY and ESCAPOLOGIST among quite a few others.
Thanks Goliath and Oriel.
That was good fun, and quite a pleasant stroll. The length of a cup of tea, in fact, which is probably mixing metaphors . . . I do the Guardian and FT, and SPEW also showed up somewhere else quite recently, probably at the former. Thanks, Goliath and Oriel.
Not much to add. Accessible and very enjoyable. So many great clues today
Thanks Goliath and Oriel
Fabulous fun indeed with lots to like. Took me two cups of tea though. Thank you Goliath and Oriel.
Thanks for the blog , great set of clues , I was looking for the trademark fission clue and it arrived with the 55 .
Fission in what sense Ros?
That was great fun. I, too, was looking for the fission (lift and separate) and spent too long trying to make something of pin+e, but fixe wasn’t a young woman.
Jamez@7 fission means splitting , we have 55 = fifty five = LV , we need to split the fives so 5 5 = V V . This setter often does this with words , indeed becomes in deed , spawn becomes s pawn .
Excellent
Throughly enjoyed.
Lovely puzzle.
As soon as I saw 55 I wondered if the answer contained LV or 55 and of course it was the latter. I didn’t know that fission clues were a trademark of Goliath. I shall try to remember in future.
Loved: ASKEW, PERNICKETY, MAGISTRATE, CONSORTIA.
Thanks Goliath and Oriel.
Raised an eyebrow at LATIN = American region; Latin America is a region, and Latin as an adjective can refer to it (more common these days as Latino or Latina), but in my experience Latin as a noun never does. But since I’m the first to object, I’m sure someone will quote the dictionary at me to prove me wrong.
Most enjoyable, with plenty of tricks to keep one alert. Thanks, Goliath and Oriel.
Thanks Goliath and Oriel.
Re 16 d, I parsed it as the blogger, 55 as VV; (we do that often in Qaos puzzles) don’t feel the need to go through LV etc.
The other signature is 20a A STONE’s THROW. I don’t know if it has a name, but I call it a “bundled anagrind/fodder”.
This was a lot of fun and not painful. Though coming from America somehow we say persnickety with the “s” in it. So for awhile I thought I had the parsing wrong. But see in Chambers you all say PERNICKETY. Really enjoyed all, very clever all around. Thank you All,
Thanks Goliath. Lots of good clues as expected with my favourites being TEAK, POLYETHELENE (great surface), MAGISTRATE, HERON, MISS, and AGED. A few quibbles — in SPAGHETTI we have wordplay ‘of’ definition which grates a bit, in HYPNOTISED we have ‘problem’ to indicate an anagram, and in TECH-SAVVY we have ‘losing’ to indicate an anagram, neither of which seem apt. Thanks Oriel for the blog.