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Winemaker’s Think Tank

The Winemaker’s Think Tank: Vol 28- What are the best ways to get maximum extraction from red wine grapes to create a dark red wine?

What’s the Winemaker’s Think Tank?

Every Thursday we will post about a few frequently asked questions that our winemaker has answered. If you have a winemaking question you would like to have answered, please email us at support@juicegrape.com and we will try to get into next week’s post. Cheers! :)

Red wine in wineglass

What are the best ways to get maximum extraction from red wine grapes to create a dark red wine? And does a large primary fermenter make a difference in extracting color etc. from red wine grapes as opposed to a small primary fermenter of, say, 5 gallons? 

There are many factors that can assist in the extraction of pigmentation and tannins from red wine grapes. A combination of some of these methods will ensure the best extraction of pigments in the red wine. The first method that will help ensure a deep bold color in red wines is a cold soak. After crushing the grapes into a fermenting tub, add 50ppm of potassium metabisulfite to prohibit microbial growth. After 6 hours, add pectic enzyme, specifically Color Pro, to help break down the grapes and assist with the color extraction. Now comes the more challenging part, the cold soak. The goal is to get the grape must to 40°F to extract the tannins but discourage bacterial growth; you may do this by bringing the fermentation tub into a cool area such as a walk in fridge (if you have that luxury) or a cold garage. If it is getting nice and cold at night, this may work fine for you. Otherwise you will have to chill down the must by adding frozen containers of water. You can fill up gallon jugs with water (that have been sanitized with potassium metabisulfite) and freeze them. Submerging quite a few of these in the must will chill it down significantly. However there is a risk of the jugs leaking. Another method would be to obtain 4inch PVC tubing and caps for the end. The PVC tubing will need to be as long as the height of your fermenting vessel. Place a secure cap on one end of the tube and seal it. (Always sanitize anything that will come in contact with your must with potassium metabisulfite first.) Fill the tube with ice and place standing upright (to the best of your ability) in the must. The solid skins and thickness of the must will help keep this upright. Then place another cap on the exposed end but do not seal it. You will have to replace the ice every 8 hours. If using 4 tubes per tub of must, this should keep the grape must around 40°F. If you can keep the must at 40°F, cold soaking it for 3 days will bring out deep pigments and provide dense color saturation. You will need to warm up the must to 65°F before setting yeast.

There are a few fermentation aids that will help with color securing. Opti-Red and FT Rouge are excellent products for this purpose. Opti-Red is a yeast derivative nutrient that helps to secure color and provide smoother tannin integration. FT Rouge is a blend of tannins that will also secure color pigments throughout fermentation. Using both of these compounds will greatly enhance the depth and richness of your red wine color.

Lastly, the shape of your fermentation vessel will mildly affect the color of your wine. If you have a tall cylindrical shaped fermentation bin, the cap will rise up and maintain less contact with the fermenting wine. Regular punch downs will be more critical. If you have a wider fermentation vessel, the surface area of the cap will increase, giving it more area to come in contact with the wine. These are subtle differences that won’t greatly affect the outcome of the wine and will not replace the incredibly important punch downs that should occur every 6-8 hours.

We hope this information helps with your winemaking. If you have any follow up questions or winemaking questions in general, please email us at support@juicegrape.com.

The Winemaker’s Think Tank: Vol 12- Common Winemaking Faults and Flaws

Wine expert testing wine silhouette image

What’s the Winemaker’s Think Tank?

Every Thursday we will post about a few frequently asked questions that our winemaker has answered. If you have a winemaking question you would like to have answered, please email us at support@juicegrape.com and we will try to get into next week’s post. Cheers! :)

In this week’s Winemaker’s Think Tank we outline the difference between flaws, faults, and how to identify them.

  • Flaws
    •  Flaws are a mistake made in the winemaking process that leads to a property in the wine that is not characteristic of the varietal
    •  Stylistic Choice vs. Flaw
    •  Imbalance Flaw
      • Acid vs Sugar, Oak Levels, Alcohol Level
    • Visual Flaws
      • Haze, Sediment, Effervescence, TA Crystals, Floaters, Lack of Color Saturation
    • Aroma/Bouquet Flaws
      • Lack of Aroma, Non-varietal aroma, Over-oaking
  • Faults
    • Faults are often a microbial or chemical reaction within the wine in some part of its life that significantly alters a wine, eventually leading to the point of spoilage.
  • Oxidation Faults
    • Acetaldehyde – oxidation of Ethyl Alcohol smells like sherry, or old apples, browning
      • Causes: headspace, low sulfites, poor corks, bacterial contamination
    • Acetic Acid – Vinegar
      • Causes: Acetaldehyde, Acetobacter bacteria react with ethanol, Fruit Flie
    • Ethyl Acetate – Nail Polish Smell
      • Oxidation of Acetaldehyde and Acetic Acid
      • Causes: headspace and bacterial contamination
  • Sulfur Faults
    • Hydrogen Sulfide – Rotten Eggs Smell
      Causes: lack of yeast nutrients, yeast stress, sulfur sprays, yeast bi-product, high temps
    • Sulfur Dioxide – Burnt Match Smell
      Causes: over sulfating, wild yeast
    • Complex Sulfur Faults- Mercaptans, DMS, DES, DMDS, DEDS
      Causes: Hydrogen Sulfide reacting with Ethyl Alcohol
  • Microbial Faults
    • Brettanomyces – Barnyard, Horse Saddle, Antiseptic Ointment, Band-Aids, Bacon, Clove
      • Causes: spoilage yeast cells that are incredibly dangerous and difficult to eliminate. Most often found in contaminated barrels, winery cleanliness, resistant to acid and SO2
    • Geranium Taint – Fresh cut geranium leaves
      • Causes: Reaction of potassium sorbate with Lactic Acid Bacteria in the presence of Ethyl Alcohol
    • Refermentation – Fizzy wine, popped corks
      • Causes: Yeast or microbial fermentation of residual sugar
  • Other Faults
    • Cork Taint – Wet basement, wet old newspaper, mildew
      • Causes: strain of trichloanisole on cork (cork taint); mold that contacts chlorine and wood
    • Heat Damage – Cooked fruit smell, brick red color, similar to oxidation
      • Causes: leaving wine in a hot car, in the sun, etc.

We hope this information helps with your winemaking. If you have any follow up questions or winemaking questions in general, please email us at support@juicegrape.com.

The Winemaker’s Think Tank: Vol 8 – Grape Yield

Wine expert testing wine silhouette image

What’s the Winemaker’s Think Tank? 

Every Thursday we will post about a few frequently asked questions that our winemaker has answered. If you have a winemaking question you would like to have answered, please email us at support@juicegrape.com and we will try to get into next week’s post. Cheers! :)

When should I bottle?

The answer to this question can have many directions. The simple answer is: when the wine is ready. On average, white wines may be bottled 6-12 months after fermentation. Red wines benefit more from bulk aging, that is, aging all of that varietal together in a large vessel such as a tank or barrel or carboy, rather than in individual bottles. A red wine should bulk age for at least a year before bottling. Premium red wines age for at least 3 years in large vessels before bottling.

Bottling Equipment

We hope this information helps with your winemaking. If you have any follow up questions or winemaking questions in general, please email us at support@juicegrape.com. 

The Winemaker’s Think Tank: Vol 1- Why is My Wine Fizzy?

 

Wine expert testing wine silhouette image

 

The Winemaker’s Think Tank? 

Every Thursday we will post about a few frequently asked questions that our winemaker has answered. If you have a winemaking question you would like to have answered, please email us at support@juicegrape.com and we will try to get into next week’s post. Cheers! :)

 

Why is my wine fizzy?

Wine may be fizzy for one of two reasons: trapped gas within the wine leftover from fermentation, or a re-fermenting wine. Yeast exudes two substances upon fermentation: alcohol and carbon dioxide. Often times, carbon dioxide is exuded in such small bubbles that the weight of the liquid wine is too heavy to allow the gas to escape. This gas can easily be discharged through a process called degassing. Degassing involves the extreme agitation of the wine via stirring or pumping over. If you own a pump, you can set up the hoses in a circuit, and pump over vigorously to allow the gas to escape. You can also buy a degassing stirring wand that attaches to a cordless power drill. Simply attach it to the drill, place in the wine, and stir. The agitation will allow any trapped bubbles to rise to the surface and dissipate.

The wine may also be fizzy due to a re-fermentation. Even after racking, there may still be suspended yeast cells within the wine. The addition of potassium metabisulfite is necessary to ensure the killing off of remaining yeast cells, especially if the wine has any residual sugar or if the winemaker has plans to back sweeten the wine. Potassium sorbate is also strongly recommended if the winemaker intends upon back sweetening a white wine. The potassium sorbate will encapsulate the yeast cells, rendering them sterile and unable to ferment any sugar that is then added to the wine. (Note: Potassium sorbate cannot be used on any wine that has gone through Malolactic fermentation.) If the winemaker would prefer physical rather than chemical sterilization, a sterile grade (.45micron) filter may be used to physically remove any yeast or bacterial cells and prevent any further fermenting from occurring in the bottle.

*Please Note:

  • Brettanomyces is carbon dioxide as well.
  • The issue of filtration raises a host of issues.  Sterile in winemaking is not achieved unless using an absolute filter (cartridge filter at the 0.45 or lower) and not a nominal filter (plate or pad filter  such as the Grifo or SuperJets).  The cartridges for the Enolomatic filter set-up are not rated as sterile either.

We hope this information helps with your winemaking. If you have any follow up questions or winemaking questions in general, please email us at support@juicegrape.com.