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Making Wine from Grapes

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#1 strangebrewer


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Posted 14 April 2009 - 04:22 AM

I put this together from my past couple years of notes as well as readings on winepress.us and Jon Iverson's book on home wine making. I know when I started down this path it was a LOT of information to learn and digest so I hope this breaks down the process and simplifies it for those interested in learning the art of wine making.First a couple abbreviations, definitions, acronyms, and conversionsKMETA: Potassium MetabisulfateH2S: Hydrogen SulfideDAP: Diammonium PhosphateMLB: Malolactic bacteria.MLF : Malolactic FermentationTA: Total Acidity36lbs of grapes (1 case/lug) will yield approximately 2.5-3 gallons of wine.Cold Soaking: Process of keeping the crushed de-stemmed grapes in the fermenter below the temperature of 50°F for 2-5 days. This does a number of things. Contact time with the skins helps with color extraction and bringing out some more of the grapes fruit characteristics.What to ferment in: Any food safe container that you can easily reach inside of. Rubbermaid Brute garbage cans are NSF 2 rated and are food grade. They make excellent fermenters and many steps much easier in addition to be easier to move around. Delstage: Process of moving the must and skins from one fermenter to another while splash racking. Helps reduce H2S issues, degasses must, and provides opportunity to remove seeds from the fermentation vat reducing tannic harshness seeds can contribute.Malolactic fermentation: The process of introducing Malolactic bacteria that convert malic acid to lactic acid. Malic acid has a harsher flavor on the pallet while lactic is a softer acid. This process helps reduce the aging time required before a wine is drinkable. While not required it is done on most red wines.Day 1 (Crush day)1. The day your grapes arrive and prior to the crush go through them and remove any mold, leaves, and badly raisined clusters. 2. Crush and de-stem. I highly recommend using a crusher de-stemmer for this. Ask your LHBS if they have one you can borrow. - As I crush and de-stem I spray the grapes going in with a KMETA solution to lightly dose the grapes - I also add an enzyme at this point to help break down the grapes as well as aid in color extraction from the skins. I use very standard Pectic but there are a variety of products available3. Cold Soak. If you have the capacity to do this then I’ve found it helps with color extraction from the grapes and intensify some fruit flavors. If you do not have the capacity or don’t wish to skip to ‘Pre-fermentation steps’. - I pull off a half gallon of juice and skins per batch and this is what I make my yeast starters from while the grapes are cold soaking. - After pulling off my starter juice I dose the must with a heavier KMETA solution. ½ teaspoon per 100lbs of grapes dissolved in water and thoroughly mixed in. This is a MUST if you are cold soaking to prevent spontaneous fermentationPre-fermentation steps*Before performing any testing steps be sure to mix the contents of the fermenter thoroughly or you may get inaccurate results.*1) Determine what you want your ABV to be in your finished wine and adjust the Brix accordingly. Generally you want your starting Brix to be around 22-24.2) To increase Brix use sugar. ½ lb of sugar will raise 5 gallons of must 1 Brix point.3) To reduce Brix use water (distilled or spring water works). 1 pint water will lower 5 gallons of must by 1 Brix point4) Test for PH and TA. Generally you want your TA to be in the .60 to .75 range. PH Generally you want to be in the 3.3 to 3.7 range. *Note: These numbers are middle numbers and are subject to personal preference*5) You will come across 1 of 4 scenarios with your grapes - The pH is high and the acid low - The pH is low and the acid high - Both the pH and acid are high - Everything is just right6) Reference this site for TA and pH adjustments: https://www.bcawa.ca...king/acidph.htm . They suggest several different additives for adjustments. I have used Tartaric acid and Potassium Carbonate myself with good success7) Finally record all your numbers.Starting Fermentation1) First you must determine which strain of yeast to use for your wine. There are a lot to pick from. Lalleman and Lalvin are two excellent producers of dry wine yeasts. Prepare cultures 24 hours prior to inoculation if possible, minimum of 12 hours.2) Determine yeast population. Inoculate at a rate of 1 teaspoon (5 grams) of yeast per 72lbs of grapes.3) Rehydrate yeast per manufacturer specifications. Go-Ferm can be used during this stage but it is not required.4) Add rehydrated yeast to juice removed prior to KMETA addition at the cold soak ensuring temp difference between juice and rehydrated yeast is within 10°F5) If you did not cold soak make your KMETA addition now to stall wild yeast prior to inoculating with rehydrated yeast at a rate of ½ teaspoon KMETA per 100lbs grapes. (always dissolve KMETA before adding to must)6) Nutrient additions. Fermaid K is the current popular yeast nutrient in conjunction with DAP. Add 1 teaspoon Fermaid K per 5 gallons of anticipated wine and 1.25 teaspoons DAP per 5 gallons anticipated wine.7) Mix all nutrients in thoroughly8) Add yeast culture and mix in thoroughly again ensuring starter is within 10°F of grape vat.Fermentation1) As your wine ferments CO2 will float the grape skins to the top and form a cap. 2-4 times a day you must break up this cap better known as punching down. This is done vigorously in order to also get some oxygen into the must. The oxygen is both vital to the yeast strength and will help prevent H2S issues.2) Make sure you clean the inner sides of the fermenter after each punch down.3) Test and keep track of your Brix and temperature daily4) 75°F-85°F is normal fermenting temps for red wines. If you start to get closer to 90°F consider freezing 1 gallon jugs (with lids tightly on) and submerging them in the fermenting must.5) When wine reaches 17-19 Brix consider an additional Fermaid K dose if 1 teaspoon per 5 gallons anticipated wine.6) A completely optional step, but can help produce a better wine more quickly, is also performed around 17-19 Brix and is a delstage.7) Complete fermentation to a final Brix of 2 to -2 depending on desired final product. +2 will be more fruit forward while -2 will be dryer and have a greater tannin structure8) At a Brix of 2 to -2 you can press or perform an extended maceration. Extended Maceration is used at time to increase the complexity of the wine, this is a personal call. - If performing an extended maceration use CO2 or another inert gas to help protect your wine since it is no longer outgassing and if you plan to do a MLF then add MLB and MLB nutrient at this time (MLB nutrient optional). Extended maceration can last as long as you wish on average anywhere from 2days to 2 weeks then proceed to pressing as usual.Pressing1) If cap is still present use a bucket to remove it and put it in the press basket. Pour the free run wine over the grapes in the press basket. Add remainder of grape pulp and press. - Depending on the size of your press, multiple pressings may be required.Malolactic Fermentation1) If you feel your wine would benefit from MLF (most reds will) then at this time add MLB.2) MLF can be temperamental and occurs best between 72-75°F. This process can take anywhere from 30-75 days to complete3) After 30-75 days test for completion of MLF. If complete rack off the fine lees.4) Make any final TA and PH adjustments desired based upon PH and taste. Again Tartaric acid works well but other products are available depending on personal taste.5) add KMETA. ¼ teaspoon of KMETA will provide 40ppm in 5 gallons of wine with a ph of 3.4. if the ph is higher than 3.4 add an additional 10ppm for every .1 over 3.4.Post Fermentation1) Cold stabilization. This is an optional step but I have found it to help clear the wine, degass, and force the precipitation of bi tartrate crystals. The process is to chill the wine to 32°F and leave it at that temp for 7-30 days. If you live somewhere with a cold winter you can leave it here all winter. 2) After Cold stabilization complete rack wine while still cold. Bi tartrate crystals precipitate out of wine when cold and will dissolve back in if the wine as the temperature of the wine rises.3) Test TA and Ph and adjust to taste or target numbersAging/Oaking1) Test Free SO2 levels every 6 months2) Most wines will benefit from some form of bulk aging. This is also the time oak is introduced. Bulk aging/oaking can last anywhere from 2 months to 2 years depending on taste and desired end results.3) Oak options: - Oak Barrel: This can take the place of the carboy in the final racking and provides many positive aspects such as micro oxygenation, more rapid degassing than glass, in addition to oaking. The length of time a wine can spend in a barrel depends on how new the barrel is, the size of the barrel, and finally the desired end result of the consumer. - Oak dust, chips, cubes, and spirals. Listed in order of price and in turn quality. Quality, quantity, toast level, and length of exposure time are all up to personal preference. You can always add oak to a wine but blending with an un-oaked wine is the only way to decrease it. Follow suggested manufacturer instructions per product and adjust for preference.4) Biolees is an optional product that can be added that imitates sur lie aging. Sur Lie aging is the process of leaving the wine on the lees for 6 months and stirring to increase mouthfeel and soften the wine. It is added 3-5 weeks before bottling at a dosage of 4.5 teaspoons per 5 gallons finished wine5) Tan Cor Grand Cru is an optional product that can be added at this stage that also helps with adding mouth feel as well as contributing some anti-oxidation properties.

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