Grape Wine Info

 

Making Varietal Grape Wine…

…is a complex series of steps measuring such properties as PH, specific gravity, and sulfur dioxide.  Wine making is also simple.  Fruit, yeast and time.  Making good wine results from getting access to good balanced grapes, and knowing what qualities are targeted or desired.  Merlot grapes, for example, can produce a light fruity acidic wine, or a heavier bodied, rich red wine with depth.  The winemaker must first get the best grapes possible and then work with their specific properties. A reputable grower or broker should provide quality fruit, within acceptable parameters (Brix, PH, Total Acid), but know that seasonal harvest variations will always occur.  A good winemaking book should not only provide a basic template or procedural recipe (see our example below), it should also help you adjust for variations. For example, in a particularly cool year, acid may be bit high, and brix low, suggesting a fruitier, more acidic Merlot, perhaps a candidate for malolactic fermentation?  For knowledgable winemakers, we offer quality grapes by special order for September harvest with access to our crusher-destemmer and wine press.  Inquire at the North Corner Brewing Supply for details. 

 

TYPICAL EQUIPMENT AND SUPPLIES FOR 5 GALLON BATCHES:

 

HARDWARE:

  • Open primary fermenters to 12 gal  total capacity
  • 5 Gallon glass secondary fermenter
  • Racking cane and tubing for transferring and bottling
  • Hydrometer, and sample wine “thief”
  • Airlock and stopper for carboy
  • Bottle filler tip (attaches to racking tubing)
  • Corker and corks or Capper
  • Funnel, 25-26 750ml wine bottle
  • Press and Crusher Destemmer*

 

MINUMUM INGREDIENTS:

  • Sulfite Agent (either bulk powder or Campden Tablets)
  • Wine yeast  (example: Red Star Pasteur Red)
  • Yeast Nutrient or D.A.P. Nutrient

 

OPTIONAL INGREDIENTS:

  • Tartaric acid (to balance low acid grapes)
  • Dextrose Sugar (to balance low sugar grapes)
  • Clarifying Agents (such as bentonite, polyclar)
  • Oak additions (in chip or “oak powder”)
  • Stabilizer (potassium sorbate) for finishing sweetness

 

*TO PROCESS BULK GRAPES, YOU WILL NEED ACCESS TO A CRUSHER-STEMMER AND A WINE PRESS.  WE CAN PROVIDE OR RENT THESE ITEMS TO CUSTOMERS WHO PURCHASE GRAPES THROUGH US

 

 

 

 A typical schedule for Merlot: 5-gallon yield

 

The following is a very simple example of a wine schedule from harvest to bottling day:

 

100lbs Merlot Grapes: 23-24.5 Brix, Acid: .65-.75, PH 3.35

3 teaspoons of Yeast Nutrient

2 teaspoons D.A.P. Nutrient (both nutrients aid the yeast in completing a thorough fermentation)

2-3 Packages Pasteur Red Dry Yeast  

Potassium Metabisulfite or Campden Tablets for 25-50ppm sulfite level in must (3-5 campden tablets typically)

Optional ingredients: Pectic enzyme, Malolactic culture (recommended at day 6-8 of warm primary ferment, see additional notes on ML below along with yeast descriptions)

Adjustments/contingencies:  Grapes will vary from year to year.  Low-level adjustments per subjective style guidelines are common.  Radical adjustments for non-standard grape varieties or Puget Sound grown grapes which struggle to attain proper ripeness may be needed to get acceptable balance. 

For low sugar must: ameliorate or add sugar to attain minimum desired original gravity (usually 12% potential alcohol)

For high acid must: agents can be added to reduce acidity such as calcium carbonate and potassium carbonate, malolactic culture will also soften acids slightly

For high sugar must: use water to thin must down to under 14% potential alcohol,

For low acid must: add tartaric acid to adjust must acidity to desired range (within reason).  An acid test kit can measure acid levels.

For high PH must: carefully measure out higher than normal S02 additions (see text information), knowing that high PH musts require higher SO2 levels for comparable stability.

 

Merlot Time-line Example:

 

  1.  On pick-up day:  Bring cleaned and sanitized primary fermenter containers for approximately 15 gallons must capacity.  Fill buckets about 2/3 full of grapes which have been run through crusher-destemmer leaving approximately 50% whole grapes.  Some stem material may be acceptable or desired.
  2.  Add sulfite, usually 25 to 50 ppm to each container. 
  3. Add rehydrated active yeast, yeast starter is recommended.  Supplemental nutrients are recommended but not required.
  4. Keep must warm (70-80 degrees) during active primary fermentation (about 7-10 days).  Must should be at least 70 degrees.  80-85 degrees will extract more robust tannins and phenols.  Keep primary containers loosely covered, punch cap down and stir twice a day during fermentation.  If wine acid is mildly high and/or malolactic conversion is desired a ML strain may be added 4-8 days into the primary ferment.
  5. Decide on your schedule for skin contact time before pressing, based on temperature and targeted wine properties, typically 7-10 days of fermentation or until gravity reaches 1.000, then press.  Longer contact results in more skin/tannin extraction. 
  6. Press out wine.  Do not over press, potentially leaching harsh flavor.  100 lbs of grape should easily yield 6 to 7 gallons of wine from the press.  Press into glass 6 or 6.5 gal carboy or poly fermenter, actively splashing wine.  Leave some head space (2-3”) for fermentation activity.  Seal with lid and airlock.  Over the next 2 weeks new fermentation activity from pressed out sugars will occur.  If you wish gain maximum yield from the press collect hard press runnings in a 1 gal jug.  Remember you’ll have to rack soon.  The obvious volume choices are 1) collect 6.5 gal from press then rack to 6 gal carboy and eventually (long-term) rack in 5 gal carboy or 2) collect 6 gal from press and 1-2 one gal jugs, rack in 5 gal carboy and eventually rack (and top-off) into 5 gal carboys long term.
  7. In 2 weeks, splash rack the wine into a 6 or 5-gallon (determined by your original press volume) carboy filled to the top, leaving sediments behind.
  8. 1-2 months later: wine should be still, but not clear.  Terminal gravity is reached.  Wine can be stored at slightly cooler than primary temps, 60 degrees recommended.  This is a good time to consider adding oak additions or fining agents to accelerate clarification.  ML conversion may be checked by measuring a very slight acidity drop, or by using lab quality blotter style ML paper.  A slight “maintaining” level of sulfite is recommended, about 10-20ppm.
  9. 1 –2 months later:  Carefully rack the wine again off sediments.  Sediment layer should be slight, wine should be clearing and conditioning. 
  10. 2-4 months later:  Wine should be clearing nicely now.  Based on overall properties, such as alcohol, skin contact extraction, sulfite level, and the use of clarifying agents, the winemaker may decide to bottle soon.  A lighter fruitier Merlot may be ready to bottle by month 6-8.  A heavier bodied, fully extracted Merlot should continue to condition at least 1 year before bottling.   Rack the wine whenever a significant sediment layer builds, up to 4 times during the life of the wine.  Always keep carboy fully topped off and sealed under airlock.  If in doubt, wait. A slight “maintaining” level of sulfite is recommended, about 10-15ppm.

Bottling Day:

Sanitize bottles and splash corks in water to facilitate corking.  A limited sulfite addition is recommended for stability or long-term aging (about 10-20ppm or about 35-50ppm total assuming a normal PH.).  When bottling, use a shut-off filler tip, attached to siphon hose.  Avoid sediments by careful racking.  A full five gallons yields about 25 750 ml bottles.  If the wine was of higher brix/longer skin extraction, with a full 50ppm of sulfite added early and later sulfite additions added, then the wine should age well.  If the wine was lighter in body/extraction or lower in total sulfite addition, expect a shorter life span perhaps peaking in 2 years, decaying by 4.  Total wine life depends on a complex combination of conditions such as acidity, PH, alcohol content, sulfite additions, storage conditions, and bottling procedures.

 


BASIC WINEMAKING CHEMICALS:

 Why use all these chemicals? Consistent winemaking requires the balancing of fundamental flavor properties in an environment free of contaminants. Wine takes a long time, and waiting a year only to have a product that is vinegar-like, spoiled, staled, too sweet or too dry or just plain dull is no fun. Spend some time designing your wine! We suggest you acquire a good basic wine book with recipes, try some proven recipes first then do your own experiments later.

Dry Wine Yeast:  Lalvin/Red Star or other 5-10 gram single yeast packets
Dry wine yeasts are easy to use and predictable. 1 5 gram dry package is sufficient for 1-5 gallons. To prepare yeast for use, rehydrate 1 package of dry yeast in approximately 8 oz warm sterile water for 10 minutes. Use a sanitized 16 oz pint glass or glass jar. At this point the yeast may be used, but we suggest making a starter in addition, especially for 3 gallon or larger batches. A starter helps get the must actively fermenting sooner. To create a starter, add 1 teaspoon or 1 crushed tablet yeast nutrient and approximately 4oz or .5 cup of your fruit must to the rehydrated slurry yeast and wait about 20 minutes or until signs of activity. For larger batches create a larger starter.  Pitch the active starter yeast into your target wine.


Different wine yeasts have different properties, tolerances, and flavors. We suggest you find out more about the yeast strains that you are using and match a yeast strain to the wine that you are designing. Here’s a description of 4 popular Red Star Brand yeast strains:

Premier Cuvee: A very good all-purpose yeast, works relatively fast, finishes dry to about 13.5% alcohol, a fast all purpose yeast!
Cotes De Blanc: A good choice for fruity wines, not very alcohol tolerant, finishes dry at around 11% Our recommended yeast for cider, fruit wines, and many light white wines!
Pasteur Champagne: A very strong, but slow yeast, also cold tolerant, can finish dry to about 14-15% Excellent for strong meads!
Pasteur Red: A classic red wine yeast strain robust and tolerant of the aggressive conditions of warm and highly extractive primary fermentaion.  Finishes dry to about 14% alcohol.

Malolactic Culture:  “ML” is a secondary bacteria added to many Red Wines and some Whites.  ML causes a slight acid reduction by converting a percentage of Malic acid to Lactic acid.  ML can also happen spontaneously especially if reusing oak barrel or sharing equipment.  The end result is a wine with more apparent “roundness” and body.  ML is also used preventively to avoid a spontaneous conversion later (such as in the finished bottle which can cause instability in the form off-flavors and carbonation).  ML conversion should not be considered obligatory.  It may make a dull wine even more bland, but winemakers considering extensive blending and reusing of oak barrels should probably consider promoting ML conversion for stability reasons alone.  This often leads to the seeming paradox of adding ML bacteria and additional acids to Red wine.  ML can be easily inhibited by maintaining consistent SO2 levels (above 25ppm and bottling at 50ppm) and by keeping wines at cellar temps (58-62) for long term bulk and bottle aging.

 

WYEAST markets high quality liquid yeast strains: We can special order any WYEAST products if you give us a 7-10 days of notice.  I’ve had good results with the WYEAST BORDEAUX strain.  Check their web site: www.wyeastlab.com/winery/wineryprod.htm


Yeast Nutrient: Yeast Energizer, Diammonium Phosphate
Yeast nutrient helps ensure complete and thorough fermentation. Highly acidic fruit wines, strong wines, Mead (honey wines) and herb wines (such as dandelion wine) all benefit from yeast nutrient, yeast energizer or Diammonium phosphate (D.A.P.). Use 1 teaspoon per gallon or 1-2 tablets per gallon.   Nutrients may prevent some cases of hydrogen sulfide “rotten egg” production.


Sulfites (Sulfur Dioxide): Potassium Metabisulfite, Sodium Metabisulfite, Campden Tablets
Sulfites (sulfur dioxide) inhibit wild yeast and add preservative effects to wine. When used judiciously, sulfites allow you to “sterilize” wild fruit and use the wine yeast of your choice, and produce a stable wine, which holds up better over time. Sulfites are generally used 3 ways; 1) to sterilize equipment 2) to sterilize the must initially, 3) and in very small concentrations added during the winemaking process for preservative and stabilizing effects. Please make a clear distinction between sulfites used for general sterilizing, and sulfites used at targeted concentrations (usually measured in PPM) in the wine!

When using sulfites to sterilize the must, 50-75ppm is the usual concentration. Some winemakers use the same concentration or a slightly higher concentration, but then allow the sulfur dioxide to off-gas over a 24 hour period, before adding wine yeast. Wine yeasts are tolerant of low levels of sulfur dioxide. Red wine makers may prefer using approximately 20-30ppm SO2 to guarantee early malolactic fermentation.

For late racking and/or bottling 15-25ppm is suggested. The use of sulfites is further complicated by the PH of wine; the higher the PH number, the more SO2 the wine needs to be effective. Please consult an intermediate level winemaking book for further information.  WINEMAKER magazine online provides a very handy calculator: http://www.winemakermag.com/guide/sulfite.

For a general sterilizing wash use 1 tablespoon potassium metabisulfite in 1 gallon of water. This solution can be poured into bottles, carboys and buckets and lightly rinsed out. The trace amounts of sulfite left on your equipment will be fine.  Do not store in metal containers or containers with metal lids!


Here’s a typical use of sulfites for a fruit wine: Fermenter sterilized with sulfite rinse, 50ppm added to wine initially, wine is racked once. Rack wine a second time for clarity and maturation. Wine is racked again (third time) and then bottled with an additional 25ppm sulfite. Sanitized bottles and new corks are soaked in a weak sulfite solution at bottling time.

Don’t be afraid of using sulfites! At low levels they are very beneficial, just don’t over do the concentrations. If you have a real aversion to sulfites, you can employ some limited strategies to avoid winemaking problems.


1 campden tablet provides 50ppm SO2 in 1 gallon of water, making campden tablets easy to use.

Sulfite powder in 2oz bags must be diluted! 

 Mix 1oz sulfite powder in 8 oz plastic water bottle. One teaspoon of this working solution equals 50ppm in 1 gallon.

     Exercise caution with bulk potassium Metabisulfite!    

Acid Blend, Tartaric, Malic and Citric Acid
Acid additives are used primarily to balance sweet flavors of the must and correct the wines’ overall balance. The acidity of wines can be measured with an acid test kit. Your recipe can provide you with basic acid/sugar recommendations, but fruit can vary from year to year and region to region, so the ideal “balance” may be quite subjective. Examples of wines that benefit from the addition of acid include apple, pear, apricot, and Mead. Generally used 1-2 teaspoons per gallon. Acid blend is a mix of citric, malic and tartaric acids. If your recipe specifies, these acids can be acquired individually. Tartaric acid is principal acid found in grapes, and thus the primary agent added to adjust grape wines.  In addition, tartaric acid is used to help stabilize Red Wines with high PH. 


Tannin and Oak Chips
Tannin or grape tannin adds a complex bite and texture to wines. Tannin is leached from grape skins and oak in traditional winemaking. For fruit wines, very small amounts of powdered tannin can help liven up low acid wines such as apple. Follow proven recipe suggestion for adding tannin. Generally used at ¼ teaspoon per gallon. Oaks chips can be added to wine late in the process to contribute oak character.

Bentonite Clay, Sparkolloid, Gelatin and Polyclar
These are common fining or clarifying agents generally used late in the winemaking process (although bentonite is a good early addition). These agents are benign, easy to add, but don’t clear up all types of haze. Most wines will clear up naturally, but fining agents speed up this process.  Lighter delicate wines benefit the most from routine fining.

Pectic Enzyme
Pectic enzyme also aids in clarification by breaking down fruit induced haze. Pectic enzyme use may helps with overall yield at press and later clarification. Certain fruits or fruit that has been heated to sterilize will produce significant haze. Pectic enzyme is generally used in the crush or primary fermenter. Recipes will provide guidelines as to the use of pectic enzyme. The general ratio is ¾ teaspoon per gallon crushed fruit.  Especially recommended for use with apples, plums, pears, and strawberries. 

Sorbistat K (Potassium Sorbate) also called "Wine Stabilizer"
Potassium sorbate is added just prior to bottling time to either stabilize a finished wine, or prevent renewed fermentation when adding sweetness to a finished wine. For a normal dry wine which has thoroughly fermented out and clarified, potassium sorbate is not necessary. For winemakers wishing to add a bit of sweetness or very strong wines which don’t ever really “finish” potassium sorbate prevents renewed fermentation and carbonation of bottled wine. If you’re not very patient, potassium sorbate may help you get a wine bottled sooner, but it is preferable to let the wine finish out at its own pace. Follow package instructions for use, generally used at ¾ teaspoon per gallon.

NORTH CORNER BREWING SUPPLY, 1220 Central, Bellingham, 360-714-1184

 

Other technical notes:

 

 Metrics Help! Use a hydrometer, acid test kit and PH meter for a better picture of what your grapes are doing. While there is not necessarily a “perfect” wine-by-numbers formula you can use these metrics to nudge the wine in the direction you desire.

 

A very generic reference point for RED and WHITES would be something like this:

 

RED WINE:  BRIX: 22.5-25, TA (of grapes)  .60-.80, PH: 3.3-3.6

WHITE WINE: BRIX: 21-24, TA (of grapes) .65-.90, PH 3.1-3.4

 

Adjustments/contingencies:  Grapes will vary from year to year.  Low level adjustments per subjective style guidelines are common. 

For low sugar must: ameliorate or add sugar to attain minimum desired original gravity (usually 12% potential alcohol)

For high acid must: agents can be added to reduce acidity such as calcium carbonate and potassium carbonate, malolactic culture will also soften acids slightly

For high sugar must: use water to thin must down to under 14% potential alcohol,

For low acid must: add tartaric acid to adjust must acidity to desired range (within reason).  An acid test kit can measure acid levels.

For high PH must: carefully measure out higher than normal S02 additions (see text information), knowing that high PH musts require higher SO2 levels for comparable stability.

 

  • Percentage crush /stems: We recommend loose crush or about 50-70% broken berries and some stem material, this is what our crusher-destemmer is set to.

 

  • SO2 and Nutrient and Yeast regime:  We suggest 25-35ppm unless fruit is showing signs of mold, high PH, or you want to inhibit ML activity.  We suggest low level use of DAP nutrient for “big” reds.  Pasteur Red is classic predictable dry yeast, Wyeast liquid strains are also available but must be pre-ordered.

 

  • Skin contact time/extraction time/temperature: “big wine” example: 80-85 degrees on skin until 1.000 “fruity” wine example:  70 degrees on skin to about 1.005 to1.010

 

  • Oxygen in the primary, splash racking: We suggest vigorous stirring/punching cap/splash into primary.  Press cap 2 times a day for heavily extracted REDS during first 10 days.

 

  • Pressing out: free run vs. press wine: We suggest medium pressing to collect about 6.5 gal from 100# Alternatively, collect smaller batch of “free run” and second “press wine” batch

 

  • Malolactic conversion: spontaneous or pitched starter? Or none? We suggest ML conversion for high acid grapes and/or “big” highly extracted Reds, and to prevent future unwanted spontaneous ML conversion in bottle.  ML conversion can be inhibited by sulfite/temperature parameters.

 

  • Oak Chips: American Oak, French Toasted, granulated Oak: We suggest using oak chips for oak tannins and flavor when using glass carboys, 1-2 oz, more for “big” reds.  French toasted oak can overwhelm thin wines.  A combination of French and American oak chips also works pretty well.

 

  • Late term issues:  reduction/oxidation/Hydrogen sulfide(H2S) production:  Wines need to racked occasionally, but also kept topped off and lightly sulfited.  Splash or copper rack wine if showing signs of reduction.  Preemptively use nutrients in high sugar musts.  Monitor your wine and troubleshoot any low-level problems before they “set-up” consult the better intermediate and advanced books that are available to home winemakers.

 

  • Bottling:  We recommend 25 to 50ppm in the finished wine at bottling time (meaning you might have to add another 10-25ppm addition to achieve this depending on you cumulative additions).  We suggest using a filler tip wand for easy filling.  Synthetic corks will allow to store bottles upright.  All natural corks require extended aging sideways to maintain a wet cork seal.  

 

 

Additional Considerations For Whites Wines

 

  • Press:  Whites are harder to press, include some stem material (a 1/3 to ½ mass) in pressing expect pressing to take longer than Reds. Or press in two smaller runs for better drainage.
  • Yeast:  For high Brix: Red Star Premier Cuvee. For low-Medium Brix: Red Star Cotes Des Blanc, Lalvin D-47, Montrachet, or Champagne (Lalvin EC 1118).  For cold aging (56-58 degrees):  Champagne or Lalvin EC 1118.
  • Cold Soak:  Some Whites benefit from cold soaking overnight on skins and pressing the next day.
  • Pre-fining with Bentonite:  Whites should have real clarity.  Bentonite is cheap, benign and easy to add.  Fining agents can also be added later.
  • Oxidation and Sanitation:  Bright acidic Whites wines really benefit from careful handling.  Don’t oxidize excessively, use robust SO2 level, ferment slightly cooler (58-65 degrees) and consider adding Ascorbic acid early in process to off set press oxidation. 
  • S02: Maintain robust S02 levels (especially if you wish to avoid ML conversion) and top off wines to minimize carboy oxygen headspace. Don’t let those airlocks dry out! 
  • Lifespan:  Typically Whites can be aged quicker and consumed earlier than Reds.  Cooler cellar temperatures also help age Whites.

 

 


We provide this information for winemakers interested in ordering wine grapes:

wine buyer information.doc (59.50 kb)




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