ACROSS
 1. WHITE'S ←RAGÙ← = WHITE SUGAR <refined sweetener>
 7. <cereal> RICE = PRICE - P
 9. <half-hearted> LUKEWARM = LUKE + WAR + M
10. ←DEB + BOB← = BOBBED <briefly curtsied>
11. I L_ after LENT = LENTIL <pulse>
12.  LO SIN GIT = LOSING IT <getting angry>
13. <one cooking> CHEF = (.i)CHE F(o.)
15. <fabric cleaners> WASHCLOTHS = WAS H CLOTS outside H_
17. <Aussie curator> GROUNDSMAN = (RODMAN GUNS)*
19. <secret message> CODE = ←(.c)E DOC(u.)←
20. <thin film> GOSSAMER = GOSS (B off AMBER)
22. <Spanish city> TOLEDO = TOO outside LED
24. <second-best> SILVER = SIR outside LOVE - O
25. <polite> MANNERLY = MAN NEARLY - A
26. <maybe burn> PAIN <French bread>
27. HAVE* ←LATE MY← = HEAVY METAL <music genre>

DOWN
 2. <quarter> HOUSE = U inside HOSE
 3. (SETTER WOVE FUNNY)* = TWENTY-FOUR-SEVEN <the whole time>
 4. <believed> SWALLOWED = S WALLOWED
 5. <risks> GAMBLES = M inside GABLES
 6. <puzzling symbols> REBUS = RE BUS
 7. ROBINS + _OLL_ EG inside ONCE = ROBINSON COLLEGE <Cambridge institution>
 8. <beloved> CHERISHED = CHER WISHED - W
14. HARM COIN* + A_ = HARMONICA <instrument>
16. <steadiness> CONSTANCY = CO (ST inside NANCY)
18. <one hammered> MARIMBA = MA + RUMBA, I←U
21. <cheer> MIRTH = ←TRIM← H
23. <Greek character> DELTA = DEALT, A→