RED WINEMAKING WITH

UNDERRIPE FRUIT


POSSIBLE PROBLEMS ASSOCIATED WITH UNDERRIPE RED GRAPES:

  • Low pigment potential
  • Underripe tannins
  • Decreased fruity aromas
  •  Higher risk of herbaceous and bitter characters
  •  pH and acid imbalances

WINEMAKING SUGGESTIONS TO COMBAT THESE ISSUES:

1. SO2 MANAGEMENT AT FRUIT RECEPTION

  •  As long as the fruit is not compromised (berries damaged via rot or pest) follow your standard SO2 protocol.
  • For compromised fruit please see rot protocol on website (www.scottlab.com/research.aspx).

2. ENZYMES

  •  Use Scottzyme® Color Pro or Lallzyme EX™ at the low range of dosage recommendations at grape reception or at crusher to maximize pigment extraction.
  • Allow 8-12 hours of contact time with enzymes before adding any fermentation tannins.
  • Note: Cold soak and/or extended maceration are not advised because they may increase green characters in wine made from underripe fruit.

3. TANNINS

Use 200-500 ppm Scott’Tan™ FT Rouge or Scott’Tan™ FT Rouge Soft, adding half at the crusher and the balance at the first or second pump-over.
  • 50-400 ppm of Scott’Tan™ Uva’Tan 100-300 ppm of Scott’Tan™ FT ColorMax may be used to increase catechin tannin.
  • Do not work the grapes too much. The enzyme will increase extraction.

4. YEAST DERIVATIVES

  • Additions of natural yeast derivatives such as Opti-RED® or ICV Noblesse® can have a positive impact on the colloidal balance of the wine. An addition of 227 g/ton of Opti-RED at the onset of fermentation provides early polysaccharide availability for complexing with polyphenols as soon as they are released and diffused. This early complexing can result in red wines with more intense color, rounder mouthfeel and better tannin integration. A subsequent addition of Opti-RED or Noblesse towards the end of fermentation allows the winemaker to shape harsh polyphenols into smoother, more approachable tannins.

5. YEAST INOCUATIONS

  • Inoculate yeast at 25 g/hL (2 lb/1000gal).
  •  Rehydrate yeast with Go-Ferm® or Go-Ferm Protect Evolution®. This is important for underripe fruit which may be low in nutrients.

6. YEAST

  • Select yeast strains that reduce the vegetal perception, express good fruit character and build mouthfeel (e.g. Enoferm CSM™, Lalvin ICV GRE™, Uvaferm BDX™ or Lalvin ICV D254®)


7. FERMENTATION NUTRIENT ADDITIONS

  • Measure yeast assimilable nitrogen (YAN) in the must. Must derived from unripe fruit is commonly YAN deficient.
  • Use Fermaid® K and/or Fermaid® O (depending on your Brix and YAN levels).
  •  Exercise caution with DAP. DAP may favor the formation of sulfide off-flavors which can, in turn, emphasize vegetal characters. In very low nitrogen must DAP should only be used in association with a complete yeast nutrient (e.g. Fermaid K).

8. MACERATION AND RACKINGS

  • Shorten maceration (skin/seed contact) to 4 days instead of 6-8 days.
  •  If you have a Guth agitator, agitate the juice twice a day underneath the cap.
  •  Rack off lees halfway through fermentation – delestage (rack and return with seed removal) between 18-15°Brix, if possible. The less contact you have with underripe seeds the better off you will be.
  • Pressing at the lowest possible pressure is critical (1 bar maximum).
  •  Keep press wine separate from free run.
  • Harsh phenolics in the press fraction may be reduced through use of Colle Perle or by lees aging using Noblesse.

9. TEMPERATURE CONTROL

  • Temperature management is important. Keep the must at 75°F (maximum) to promote fruit driven aromas and maintain heathy yeast.

10. END OF ALCOHOLIC FERMENTATION

  •  Rack 24 hours after fermentation is finished.
  •  Rack again 2 days later.
  •  If persistent vegetal characters exist, try a 10 g/hL addition of Noblesse.

11. MALOLACTIC BACTERIA SELECTION

  • Choose strains noted for mouthfeel enhancement such as Lalvin MBR VP41® or Enferm Alpha™ and rehydrate in Acti-ML or use in conjunction with ML Red Boost. Using 1-Step strains like 1-Step® VP41 or 1-Step® Alpha works very well and may improve success.
  • Inoculate as soon as possible.

12. SO2 LEVELS POST FERMENTATION

  •  Increase SO2 levels once MLF is finished. Do not leave the wine unprotected!

13. ADDITIONAL TOOLS

  • Grape tannins such as Uva’Tan and Scott’Tan™ Uva’Tan Soft can also help compensate for tannin deficiencies.
  • Cellaring tannins such as Scott’Tan™ Tannin Estate and Scott’Tan™ Tannin Complex can aid in filling tannin voids.
  • The toasted character of some finishing tannins such as Scott’Tan™ Tannin Riche and Scott’Tan™ Tannin Riche Extra can help reduce the perception of green characters.
  • For removal of harsh perripe fruit, try Colle Perle or even an addition of Noblesse (see point 8).
  • For more information on protocols dealing with underripe fruit please see Dominique Delteil’s protocol on the website(www.scottlab.com/research.aspx).
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