This document provides information on different aspects of olive production, including classification, common cultivars, flowering and fruit set, harvesting, processing, and producing olive oil. It describes the morphology and growth characteristics of olive trees. It discusses cultivation practices such as irrigation, pruning, thinning, and stress management. It explains the processes for producing black ripe olives, green olives, and olive oil. It also defines terminology and classifications used in olive oil production.

1. Olives
Olive Production Manual
Louise Ferguson, G. Steven
Sibbett, and George C. Martin

2. Classification
• Family - Oleaceae
–Genera
• Fraxinus (ash)
• Ligustrum (privet)
• Syringa (lilac)
• Olea (olive)

3. Olea europaea
• Long lived evergreen trees
• Wood resists decay
• Top dies - stock sprouts
• Roots only 3 - 4 ft (1 m) deep
• Dense foliage, poor light penetration,
cascading multiple branches, heavy
fruit on terminals

4. Leaves
• Thick, leathery, oppositely arranged
• Each leaf grows for 2 yrs
–Spring abscission in 2 to 3 years
• Stomata on lower surface only
–nestled in peltate trichomes

5. Cultivars
• Ascolano 9 gm / 18.8% Blk Grn
• Manzanillo 5 gm / 20% Fr, Blk, Oil
• Sevillano 13.5 gm / 14.4% Blk, Grn,
SpGm
• Barouni 7.4 gm / 16.5% Fr Blk
• Mission 4.1 gm / 21.8% Blk Gr Oil

6. Manzanillo
• Most widely planted
• Most popular for canning
• Low spreading 15 - 30 ft.
• Rooted Stem cuttings
• Not tolerant to cold
• Olive knot - Verticillium wilt

7. Sevillano
• Second most popular
• Spreading 25 - 35 ft tall
• Trained low for easy harvest
• Largest fruit in California
• Grafting 1 yr rooted cuttings
• Somewhat resistant to cold
• Bruises easily

8. Ascolana
• Rounded shape 20 - 30 ft tall
• Bruises easily
• Only 3 % of acreage in CA
• Canned ripe olives
• Fairly resistant to olive knot

9. Mission
• From Mexico in 1769, not Italy
• Tall upright, 40 - 50 ft
• Topped to facilitate harvest
• Small, low 6.5 : 1 fruit-to-pit ratio
• Rooted cuttings
• Trees survive 8oF

10. Mission Harvest
• Picked green - Spanish Green
Processing because they are late and
need to avoid frost.
• Red coloration - Ripe olive processin
• For oil because of high (21.8% oil)
• High monounsaturated fatty acid

11. Barouni
• From Tunisia in 1905
• Small tree 15 - 25 ft. spreading
• Large fruit, low fruit to pit ratio
• Resistant to cold
• For fresh use - process quality low
• Used for black-ripe table olives

12. Flowering
• Summer 2000 - Induction in veg buds
• Nov. 2000 - Floral induction
• Winter 2000 / 2001 - Chilling
• Spring 2001 - Flowers open

13. Chilling is Critical
• Optimum Flowering if chilling temps
–Maximum 60 to 65oF
–Minimum 35 to 40oF
• Poor flowering if
–Constant 55oF
• No flowering if
–No temp > 45oF or < 60oF

14. Influence of Leaves
• Very little dormancy
–Veg. Buds grow at or > 70oF
• Inflorescence formation
–Requires leaves on fruiting shoots
–Thus, prevent defoliation
• Hot winds can defoliate

15. Flower Buds
• Abnormally cold spring temps
–Detrimental to flower buds
• Floral differentiation 8 - 10 weeks
before May bloom
–Irrigate to prevent stress
–Start season with moist profile
• Playing catch up will not do

16. Stress
• Causes predominance
–Of male flowers
–Why?
• Girdling can increase flowering
–Danger of Olive Knot
–Not a problem in Israel
–Root reduction

17. Pollination
• Monoecious
• Flowers borne axially along shoot in
panicles
• Self and cross pollination occurs

18. Fruit Set
• 500,000 flowers per tree
• Need maximum of 10,000 fruit (2%)
–98% abscise in 14 days
–Goal is 3 tons per acre yield
• Sometimes insufficient perfect
flowers to set full crop
• Need 10% set if inflorescence limited

19. Fruit Formation
• Embryo development
• Mature ovule (seed)
• Mature ovary (fruit)
• Requires rapid pollen growth
–Delays caused by cool temperature
• Parthenocarpic fruit (shotberries)

20. Sigmoidal Fruit Growth
• Endocarp (pit) enlarges to full size
and hardens in 6 weeks
• Endosperm (liquid to solid)
• Embryo development
• Embryo maturity (September)

21. Maturation
• Gradual growth
–Mesocarp (flesh)
–Exocarp (skin and peel)
• Color change (harvest index)
–Green  straw (optimal)  Red
(maybe)  Black (unacceptable)

22. Harvesting
• Profit or loss depends on accuracy
of harvest in October
• Delaying harvest = heavier fruit
(more valuable)
• Delaying too long = black fruit & frost
damage
• Oil content increases in January

23. Fruit Thinning to Avoid
Alternate Bearing
• Hand thinning
–Both hands - heavy rubber gloves
–Strip fruit while leaving leaves
• Leave 6 fruit / foot of twig
• Complete 3 weeks after full bloom
• Effective but not cost effective

24. Thinning by Pruning
• Prune more heavily on “on” years
• Prune more lightly on “off” years
• However, not cost effective

25. Chemical Thinning
• NAA effective but must treat prior to
knowledge of crop size
• Treat 12-18 days after full bloom (FB)
• Apply 10 ppm for each day after FB
–15 days after FB = 150 ppm
–Dilute spray (300 - 400 gal water
per acre

26. Thinning Ornamental Olives
• Olives in landscape are more
desirable if all the fruit are removed
• Use 200 ppm 2-3 days before FB
–Use second spray 1 week later
• Large trees require power sprayer
–10 - 15 gal per tree
• Detrimental if temperature > 100oF

27. Processing Olives
• Types
–Black-ripe (BR) - 99% in CA
–California-style green
–Spanish-style green (<1%)
• Pickling - process of adding lactic or
acetic acid

28. Chemical Composition of
Ripe Mission Olives (%)
• Water 55.0
• Brix 13.1
• Oil 21.4
• Sugars 4.6
• Protein 1.7
• Mannitol 4.4

29. Oleuropein
• A glucoside (bitter factor in fresh
olives)
• Destroyed by dilute alkali at room
temperature
• Remove alkali (1 - 2% lye) and
bitterness does not return

30. Pigments
• Anthocyanins are major pigment
• Increases until fruit is ripe
• Decreases in overripened fruit
• Light increases formation
• 10 times more anthocyanin in fruit
ripened in light vs dark

31. Salt Free Storage
• Acidulant solution
–0.67% lactic acid
–1.00% acetic acid
–0.30% sodium benzolate
–0.30% potassium sorbate

32. Traditional Brine System
• Concrete or wooden tanks
• Capacity - 20 tons
• 5.0 - 7.5% NaCl
–20 - 30o Salometer
–Saturated solution - 26.5% salt =
100o on Salometer

33. Storage Containers
• Open-top redwood tanks 5x6 ft
• Holds 2.5 tons of olives
• Polyethylene 6 mil plastic prevents
contact between olives and inside of
tank
• No fermentation in this system
• Flavor better than in brine

34. California Style Black Olives
• Paraffin or plastic lined 20 T tank
• Four overhead pipes
–Water
–Dilute dye
–Dilute brine
–Compressed air

35. Lye (NaOH) Treatment
• 3 - 5 applications of 0.5 - 1.5%
• Better color by
–Reducing lye concentration
–Increasing treatment numbers
–Reducing duration

36. Color Formation
• Lye helps
–Natural phenolic compounds to
oxidize and polymerize
–Causing formation of black
pigment
–Provided aeration is present

37. Calcium Helps Fix Color
• Color formation most rapid at 8.0 to
9.5 pH
• Retention better in hard water
• Ca(Cl)2 (0.1 - 0.5%) improves color
retention

38. Lye Removal
• Lye removed by changing water in
tanks at least twice daily
• Solution stirred frequently with
paddles of compressed air
• Lye removed in 3 - 4 days

39. Canning
• 7.0 - 7.5 pH at time of canning retains
color
• Packed in C-enamel lined cans
• Filled with 2 - 2.5 % salt brine
• Cans exhausted at 199 to 205oF for 5
min to reach 170oF or higher

40. Finish Canning
• Rebrined and sealed at 170oF in a
double seamer
• Olives in glass containers processed
in retort for 70 min. at 240oF

41. Spanish-Style Pickled Green
Olives
• Fruit reaches full size but harvested
before color changes
• Promptly placed in shallow paraffin -
or plastic-coated concrete pickling
vats

42. Lye Treatment
• Dilute lye (1.25 - 1.75%) at 54 - 70oF
penetrates 3/4 way to pit in 8 - 12 hrs.
• Small amt of untreated bitter flesh
characteristic of green olives
• 1 drop of phenolphthalein to cut
surface shows depth of lye
penetration

43. Post Lye Treatment
• Olives washed in cold H2O 24-36 hrs
• Water changed every 4 - 6 hrs
• Then response to indicator very faint

44. Fermentation
• Washed, lye-treated olives
transferred to 50 gal oak barrels
• Head replaced and hoops driven
• 11% brine added through side bung
–Lactic acid content 0.8 - 1.2%
–3.8 pH or less
• Fermentation at 75 - 80oF for 1-12 mo

45. Producing Olive Oil
• Spain, Italy, and Greece (in that
order) produce 80% of world’s oil
• They consume 75%
• USA < 1% of world’s olive oil
• International Olive Oil Agreement
• Administered by International Olive
Oil Council in Madrid, Spain

46. Fatty Acid Profile
• Oil Saturated Unsaturated
• Mono Poly
• Olive 1st CP 3 88 9
• Olive 2nd CP 11 83 5
• Pecan C P 9 73 18
• Cardin Pecan 5 85 10
• Walnut EP 9 18 73
• CP = Cold Pressed, EP= Expeller Pr

47. Definition of Olive Oil
• Olive oil - obtained solely from olives
• Excludes oil extracted by solvents or
reesterification processes, or any
mixtures with other oils
• Pure olive oil cannot be any olive
residue oils

48. Virgin Oil
• Mechanically pressed from olive fruit
without using heat - cold pressing
• Only washed, decantation, and
centrifugation (natural product)
• May have vintage years on label

49. Grades of Virgin Oil
• Virgin Olive Oil Extra
–Extra Vergine (Italian)
–Vierge Extra (French)
• Pure unadulterated oil from top
quality olives
• Perfect taste and odor
• Max of 1% acid and strong odors

50. Other Olive Oils
• Virgin Olive Oil Fine or Fino
–Almost perfect taste but 1.5% acid
• Semi-fine or Ordinary Olive Oil
–Good taste maximum acidity 3.3%
• Virgin Olive Oil Lampante > 3.3%
–Not for human consumption

51. Poorer Grades
• Refined oils
–Caustic soda used to purify virgin
oil from cull fruits
• Blended oil
–Blend of refined and virgin oil
–Most imported olive oil in USA

52. Residue Oil
• Olive-residue oil obtained by treating
pomace with solvents

53. THE END