Making grape wine

[Yeastie]

My neighbor has a grape vine which produced more fruit than she could use so she let me harvest all the grapes which I plant to make into wine. I have made plum wine before based on a recipe I found on the internet and it turned out pretty good.

The grapes are small most smaller than a dime and dark purple when ripe. They have thick skins and a gel sack like concord grapes. I would like to make a red wine sweet or semi sweet wine (I realize I will have to backsweeten.) However, I haven't found as much information as I expected and am looking for some recipes or pointers. Does this recipe look good? http://www.grapestomper.com/recrwgrape.html Is it standard practice to add so much water and sugar to the grape mash? Also is there no need for a press to separate the skins from the juice?

Also I have seen mentions of adding acid blend to achieve desired acidity in the must, some of the grapes have some tartness even when ripe do you add a base such as sodium bicarbonate if the must is too acidic or is this unlikely to happen? Also any particular wine yeast recommendations?

 

[Yooper]

You probably don't need any acid. In fact, the grapes are probably pretty acidic on their own and you may have to use some water to dilute the acidity, and add sugar to raise the SG to make wine.

I use all sorts of native grapes for wine- concord, a Beta cross, catawba, etc, and it's enjoyable but not anything like using wine grapes.

My favorite info on native grapes and using them for wine is here: http://winemaking.jackkeller.net/natives.asp

 

[Honda88]

Also make sure you harvest them when they are at their full sugar potential or at least close to it or you will have bitter low character wine.

 

[Yeastie]

Thanks for the advice, unfortunately I harvested a bit early and the grapes definitely have a tartness to them. I like pictures so I decided to catalog the process for those of you interested.

Here are the grapes, approximate weight of harvest was 87.5 lbs (39.7Kg).

Here is a closeup showing the varying degrees of ripeness, most of the grapes fell somewhere in between these two.

The grapes are likely a concord variety and are slip skins which means exactly what it sounds like, the thick skin slides off revealing a jelly ball of grape flesh.

The leaves were removed and the grapes were washed with cool water and drained. The grapes were mashed in a 5 gallon bucket with a pick handle covered with a ziploc bag. Only about 1 gallon of grapes were mashed at a time to insure a good crush.

Once the grapes were crushed the stems were removed as they would leach tannins which would impart a bitter flavor.

The must after being destemmed:

The total yield of must was approximately 8 gallons.

5 camden tablets were crushed and dissolved in some warm water then added to the must and stirred. The must was covered with a clean sheet and allowed to sit for 12 hours after which point 3.5 teaspoons of pectic enzyme dissolved in water was divided between the buckets and stirred. The must was allowed to sit for an additional 12 hours. Then a portion of the must was filtered through a paper towel and the sugar content measured at 11 brix. This guide http://www.grapestompers.com/articles/chaptalize_wine.htmwas used to determine the amount of sugar needed to raise the sugar to 24 brix, approximately 4.3Kg. Portions of the must were strained and put in a pot were the sugar was added in portions. The liquid was returned and the process repeated until all the sugar was added, being sure to check the gravity every couple of additions. It is important to filter the must through a paper towel or similar before taking gravity readings as suspended particles increase density and give false readings.

Chaptalization:

As the must was being chaptalized a sachet of Pasteur Red wine yeast was rehydrated in 1/2 cup of warm water with 1/2 cup of filtered must. The yeast was distributed between the buckets and stirred then covered with a clean sheet. After 24 hours the fermentation has caused the grape skins to rise creating a cap which must be punched down by stirring. Failure to do so may allow foreign fungi and bacteria to colonize the must leading to off flavors.

The cap:

The cap must be punched down every 12 hours or so. That's as far as I've got so far I'll try to keep this updated as I go through the major steps, next up malo-lactic fermentation and pressing the must.

 

[Yooper]

The cap must be punched down every 12 hours or so. That's as far as I've got so far I'll try to keep this updated as I go through the major steps, next up malo-lactic fermentation and pressing the must.

Just for clarity for people reading, the pressing is next.

MLF happens much later, after fermentation is over.



Anyway, I like concord grape wine, but the grapes are very acidic. It's common to use some water in them, to dilute the acids, and often the sugar is mixed into the water to bring up the SG to appropriate levels. This wine may be very acidic, so I would consider that as well as consider adding some powdered tannin to help balance the acid load in the flavor. If the pH gets too low, fermentation may stall.

 

[Yeastie]

I have heard that malo-lactic cultures can be pitched at the same time as yeast or after the yeast fermentation completes, however, I talked to a guy from my local wine making club who suggested that I pitch malo-lactic cultures as soon as possible. I have some potassium carbonate and phenophalin as well as NaOH solution. Do you think I would be better off trying to adjust the pH/Total acid now or later either after pressing or before bottling? I imagine I might want to hold off at least until MLF as that could reduce the acidity further leading to not enough acidity.

 

[Honda88]

The under ripe grapes will probably be a problem but for educational sake this is awesome and thank you so much for taking pictures and sharing your journey.

Are you planning on pressing while fermentation is still going or are you going to wait until it is complete?

 

[Yooper]

I have heard that malo-lactic cultures can be pitched at the same time as yeast or after the yeast fermentation completes, however, I talked to a guy from my local wine making club who suggested that I pitch malo-lactic cultures as soon as possible. I have some potassium carbonate and phenophalin as well as NaOH solution. Do you think I would be better off trying to adjust the pH/Total acid now or later either after pressing or before bottling? I imagine I might want to hold off at least until MLF as that could reduce the acidity further leading to not enough acidity.

Adjust the acid first, so that you could make sure to have a good fermentation. If the wine tastes too acid afterwards, that still should be ok because MLF will lower the acidity as well, presuming that you have a lot of excess malic acid. You can also cold stabilize, which will precipitate out excess tartaric acid before bottling.

MLF doesn't do well concurrently with primary fermentation. That should be done after fermentation ends.

 

[Yeastie]

Just tested the acidity of the must and got ~13.08 g/L. Yikes! Way high, I have some potassium carbonate but apparently that should only be used to reduce acidity by 2-3 g/L seeing as my target range is 6-8 g/L that won't cut it. Apparently calcium carbonate can be used. Can I use calcium carbonate to reduce the acid by 5-6 g/L without serious ill effects? Do I have a choice?

 

[Yooper]

Just tested the acidity of the must and got ~13.08 g/L. Yikes! Way high, I have some potassium carbonate but apparently that should only be used to reduce acidity by 2-3 g/L seeing as my target range is 6-8 g/L that won't cut it. Apparently calcium carbonate can be used. Can I use calcium carbonate to reduce the acid by 5-6 g/L without serious ill effects? Do I have a choice?

I wouldn't. That's too much of an acid adjustment. Most people that use native grapes dilute the must with water/sugar to lower the acidity. I'm not sure how else to work with a very acidic must with unripe grapes, sorry!