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Concord Grape Wine Adventure Diary

red wine in wine glassDiary from start to finish of making Concord grape wine at home. The original articles appeared on dougthecook's blog, starting Oct 26, 2011.


Concord wine recipe - this is the recipe I used to make Concord grape wine.

Actual Timeline

Day 1 (2011-Oct 26) – load primary fermenter with grape juice, additives. Measure acid, make adjustment.

Day 2 (2011-Oct 27) – A.M. stir in pectin enzyme. P.M. check specific gravity. Adjust, if necessary. Pitch yeast. Fermentation starts. Ambient temp: 70 degrees.

Day 5 (2011-Oct-30) - Had to restart fermentation.

Day 11 (2011-Nov-5) – fermentation mostly done. Rack into container with airlock (anaerobic fermentation starts). Move to cooler (60 deg) place.

Day 41 (2011-Dec 5)  - rack into container with airlock.

Day 77 (2012-Jan 11) – rack into container with airlock.

Day 167 (2012-Apr-12) – stabilize wine.

Day 168 (2012-Apr-13) – sweeten wine.

Day 185 (2012-May-5) - rack into bottles.

Day 196 (2012-May-16) - move bottles to final storage.

2012-Aug-5 - first tasting.

Day 0 - Oct, 2011 - picking grapes

We picked several bushels of Concord grapes from 40 year old vines. It was one of the best years.

Day 1 - Oct 26, 2011 - load primary fermenter

Off we go!

Note that I sanitize everything in a solution of 1 tsp potassium metabisulfite and 1 gallon water. After much searching, no one can agree on what makes a good equipment sanitizing liquid. I’ve seen measurements from 1 tsp to 3 tbsp of potassium metabisulfite to 1 gallon water.

Placed 6 cups grape juice and 10 cups water (I used reverse osmosis water) into primary fermentation pot. Stirred in sugar, yeast nutrient, and one crushed Campden tablet. Covered and set aside.

Day 2 - Oct 27, 2011 - prepare must for fermentation

In the morning I stirred in pectin enzyme into grape solution. The pectin enzyme clears out pectin which makes wine cloudy. Covered with cloth.

Waited several hours. Took the specific gravity: it was 1.076. It should be at least 1.095. I added 1 cup sugar and mixed well. Let it sit for a few hours, stirred, then measured specific gravity: it was 1.096. You don’t want to get the S.G. much over 1.100 or else the sugar overload will kill the yeast.

pitch the yeast

I am using Montrachet wine yeast. After much research, I found out that there is 1 gram of yeast for every gallon of must. 1 gram is approximately 1/3 tsp of yeast. Note that a gram specifies weight whereas teaspoon specifies volume, so I had to find out the proper conversion for yeast.

I started rehydration of the wine yeast. Added 1/3 tsp yeast (1 gram) to 1/4 cup 105 degrees water. Let sit 15 minutes. It was starting to bubble. Added 2 tablespoons of wine juice to get the yeast accommodated to it. Waited a few hours then added mixture to grape solution. Covered back up with cloth.


Next time:

1. Make yeast starter

2. added the rehydration fluid about 20 minutes, which is what Lavlin yeast directions suggest.

3. Stir 3 times daily to agitate and distribute yeast.

Day 3 - Oct 28, 2011

Not much to do today. Saw several bubbles around the edges – tells me the yeast is at work. Stirred up the juice and covered back up. Tomorrow, I’ll check the specific gravity. The ambient temperature is about 71 degrees (ideal is 70 to 75 degrees).

As the yeast convert sugar into carbon dioxide and alcohol, the sugar content (i.e. specific gravity) goes down. Our target is 1.030 which means the juice can be transferred to an airlock container. I’m using a gallon cubitaner (plastic cube shaped container) which was from a wine kit I used in 2006. It has an airlock on it.

Day 4

Took the specific gravity of the must: 1.092

Very little bubbles on top. Lack of bubbles and high specific gravity tells me the yeast is not working. They were working great in the rehydrator (i.e. yeast in warm water with later added must). After I poured it into the must it seems all activity nearly stopped. There were a few bubbles around the edge but that is about it.

The temperature of the must vs. rehydrator was about equal.

Stirred every day to distribute the yeast.

I’ll move wine to cubes with airlocks and put in room at 72 degrees.

I moved the wine (not racked) using a ladle to a cubitainer with airlock. Use a sterilizing solution, not water, to fill the airlock half full. Room temp is 70 degrees. Covered cubitainer with cloth to keep any residual light out. I’ll be looking for bubbles in airlock which shows sign of CO2 being given off by yeast.

Day 5

I decided last night to restart the stuck fermentation. I sprinkled 1/4 tsp of wine yeast in the solution and let the yeast rest on top (to get some oxygen).

This morning: bubbles galore! The yeast does not start fermenting immediately, but reproduces the first 12 to 24 hours hence little visual activity.

I’ll take an S.G. reading after fermentation subsides. Target: 1.030. This tells us the yeast is doing its job. Then the must gets racked to another airlock container.

This may be the cause of the stuck fermentation:

Day 2 describes the method I used to introduce the yeast to the must. But according to Lavlin (maker of the Montrachet yeast) website:


Dissolve the dry yeast in 50 mL (2 oz) of warm NOT HOT water (40�- 43�C / 104�-109�F). Let stand 15 minutes without stirring, then stir well to suspend all the yeast. Add to previously sulfited must.
(The yeast should not be kept in the rehydration medium longer than recommended.)

Note you can also stir in 1/4 tsp. of sugar to proof the yeast. Check with the yeast manufacturer because it may not be necessary, or desired.

Day 7

The must is still fermenting. There is an odd smell (not like rotten eggs, which would indicate the presence of hydrogen sulfide).

I’m learning about the role of sulfites in winemaking (preserves). Adding sulfites adds sulfur dioxide which does several things: kills bacteria, speeds up alcoholic fermentation, prevents oxidation, and spontaneous fermentation of wild yeasts. Heating the must above 176 degrees F obviates the need for sulfur dioxide.

Well, whoops. I just found out that a sterilizing solution (not just plain water) should be used in the airlock. Sterilizing solution: 2 oz metabisulfite in 1 gallon water. I’ll keep it sealed in a jug for later use.

Day 11 - Nov 5, 2011

The yeast activity has definitely subsided. It has been about 6 days since fermentation started.

The hydrometer I use is calibrated to read accurately at 60 degrees; note this is the temperature of the liquid being measured, not ambient air temperature. The liquid (i.e. must) is 72 degrees. According to the hydrometer correction chart, which I’ll publish later, I add .0013 to the initial s.g. of 1.096 giving me the corrected 1.0973. I’ll use 1.097.

Since the must s.g. started at 1.097, I expect the wine to contain about 13.5% alcohol.

Beginning s.g. – ending s.g. * 125 = % alcohol by volume (ABV). So far, (1.097- .995) * 125 = 12.75%.

I measured the specific gravity today and it was below 1.000; around 0.995.

I racked the wine into another cubitainer (the secondary fermenter) using an auto siphon. I practiced using the siphon in a gallon milk jug filled with water siphoning into an empty gallon milk jug. I must say it worked very well though it took several pumps of the siphon to get it going. The cubitainer containing the must was about three feet higher than the new cubitainer. I put both cubitainers in 5 gallon plastic buckets I got at a grocery store. I refilled the airlock with new sterilizing solution.

I sampled the wine and it tasted pretty good – no off tastes and not sickenly sweet.

I moved the wine to the basement where the temperature is about 60 degrees.

One thing I have not measured is the acid level. Unfortunately, this needs to be done before fermentation, where the acid level can be adjusted. I need to order an acid titration kit (around $10) to do this next time. I am a firm believer in “you can’t control what you don’t measure”.

Another late finding: several green grapes were included in the must. These are unripe grapes which means they have too much acid and not enough sugars. Next year, the green grapes go into the trash bin.

And another late finding: the must leftovers were tossed. I found out many old vineyards spread them around the base of the vines for compost/fertilizer. Supposedly, this makes the grapes hardier. Next year, this will happen.

Next step: Dec 5, 2011 – rack wine into other cubitainer.

Day 19

I hope I did not introduce metallic contamination. I used a metal soup pot for the primary fermenter. I’ll have to find out if it is stainless steel; I doubt it. Also, I used a sterilized metal soup spoon to stir the must; should have used a long plastic food-grade spoon or glass rod. The metal may have introduced a colored haze to the wine.

The soup pot and metal spoon were stainless steel, which is ok. Wooden spoons are discouraged because they are difficult to keep sanitized. Next time I’ll use food-grade plastic spoon.

Day 20

Learned today that moving wine from fermentation environment (70 to 77 degrees F) to a cooler environment (60 degrees) helps clarify the wine. The temperature drop is the reason. I am fortunate to have a basement which is around 60 degrees. Hopefully this will help enough so fining agents do not have to be used, as they can alter the taste of the wine. Plan to rack two months then another two months for clarity.

Day 21

Bulk aging is better than bottling wine and letting it sit. The temperature variation is a lot less on a bulk of wine than individual bottles.

I plan on letting the wine sit several months before bottling as quickly as possible. The drawback is the container is tied up aging wine rather than making new wine. Since there are no immediate plans to make another batch of wine, I’ll use the cubtainer for aging.

Day 22

Why rack wine every few months? Why not let it sit until ready for bottling?

Autolysis. Yeast cells remaining will eventually feed on the lees. This induces bad flavors into the wine. Racking every few months will prevent this.

Day 28

Overview Timeline

Day 1 (Oct 26) – load primary fermenter with grape juice, additives. Measure acid, make adjustment.

Day 2 (Oct 27) – A.M. stir in pectin enzyme. P.M. check specific gravity. Adjust, if necessary. Add yeast. Fermentation starts. 70 degrees.

Day 11 (Nov 5) – fermentation mostly done. Rack into container with airlock (anaerobic fermentation starts). Move to cooler (60 deg) place. Note this should have been Day 7 or Day 8 but I had to restart fermentation.

Day 41 (Dec 5)  - rack into container with airlock

Day 71 (Jan 5) – rack into container with airlock

Day 75 (Jan 9) – fining, if necessary

Day 85 (Jan 19) – stabilize wine

Day 86 (Jan 20) – sweeten wine, if necessary

Day 96 (Jan 30) – rack into bottles

Day 44 - Dec 8, 2011 - rack wine

It has been a month since I filled the current secondary fermenter.

After sanitizing the necessary equipment (cubitainer, siphon, siphon hose, hydrometer, hydrometer test tube, airlock), on Dec 5th I racked the wine to a new container. The racking took out all but about 1/4 inch of the wine. There was some definite lees on the bottom.

The clarity is cloudy; hopefully it will go away as the wine ages.

I filled the hydrometer test tube about 2/3 full and measured the specific gravity. It was a little less than 1.000 which means no or very little sugar left.

Why less than 1.000? The alcohol is less dense than water and practically no sugar is left so with a mixture of water, alcohol, and no sugar, the density is less than water itself (1.000).

To measure the remaining sugar, a sugar analysis kit would be needed since the level of sugar is so low (around 1%).

I sampled the sample (about 1/2 glass) and, wow, that wine is for adults only. It will need to be sweetened before bottling, but the yeasties did their job.

I was happy that the taste was good; no off flavors.

Day 51 - Dec 15, 2011 - sweetening and stabilizing

The next major step in the Concord wine adventure, assuming the wine will clarify from racking a few times over several months, will be stabilizing and sweetening. The plan is for this to occur in Jan or Feb 2012.

I have been researching the best way to sweeten wine, since Concord wine needs it.

After the wine is clear, it is time to stabilize and sweeten the wine. They both go together because adding sugar back to the wine might restart fermentation so killing the yeast when adding sugar is necessary.

Stabilize the Wine

Add stabilizing chemicals. In our case, 1/2 tsp. potassium sorbate (1 gram) and 1 crushed Campden tablet (per gallon wine) . Wait one day before sweetening so the yeast is inhibited.

Free sulfur dioxide, at the time of bottling, needs to be at least 30 ppm. A Campden tablet provides 45 to 55 ppm.

Adding Stabilizer

To add stabilizer, draw out one cup of wine using a wine thief and mix in stabilizers until completely dissolved. Add back when racking as racking will mix the stabilizer.

Sweeten the Wine

Since sugar (granulated white sugar bought at any supermarket) and water can have contaminants, they must be boiled for at least 1 minute (3 minutes if you live over a mile above sea level). Boil (microwave works great. I make the syrup in a large coffee cup) 1/2 cup water then add 1 cup sugar and stir until dissolved. Boil for one minute then let cool to room temperature. Add 1/2 cup syrup to wine, gently stir (I use a sanitized long stainless steel spoon), and taste. Add another 1/4 cup, if necessary.


Put the airlock back on and let sit 1 to 4 weeks (longer the better) to make sure no fermentation starts.

I expanded on the subject here: winemaking: sweetening.

Day x - Jan 11, 2012 - rack wine

I racked the wine again. There was sediment (lees) on the bottom so I had to be careful. The lees was noticeably less than when I racked in December.  The wine is still a bit cloudy. I lost about 2 cups due to racking. I am going to bulk age another two months before bottling due to cloudiness.

Day 167 - Apr 12, 2012 - back sweeten

Yesterday I stabilized the wine by adding 1/2 tsp potassium sorbate and 1 crushed Campden tablet (in a sanitized mortar and pestle) to one cup wine. Stirred until dissolved then put into sanitized cubitainer. Then I racked the wine into the cubitainer and let it sit overnight.

Since I have about 3 bottles worth of wine (1 bottle loss due to racking), I added a sugar formula of 2/3 cup sugar, 1/3 cup water, boiled one minute. After cooling to room temperature, I poured it into the cubitainer and gently stirred with a sanitized long stainless steel spoon.

The wine will sit about one week to make sure no fermentation starts; then it is bottling time.

Day 185 - May 5, 2012 -  bottling

Finally! Time to bottle.

I ended up with three 750 ml bottles of wine (and a little extra for my effort :) ). The taste was pretty good but could have used a smidgen more sugar.

Originally, I poured boiling water into the bottles and let them simmer for several minutes. The bottles, screw cap, were soaked in sanitizing mixture for 10 minutes, along with the caps and siphon. The wine was siphoned into the bottles, leaving 1 1/2 inches of headroom (not by design). I lifted the wine bottle up to stop the siphoning, but some wine was sucked back into the cubitainer. That was not expected. Next time, I’ll get a shutoff to prevent this.

The bottles will sit in a container for a few days, standing up, then age for several months. This lets the cork form a tight seal.

Day 196 - May 16, 2012 - Post bottling

I put the corked wine bottle on its side and left the two screw-top bottles upright. It is recommended to let them age for two years. Since they have already bulk-aged half a year, only one and a half left. I’ll try the corked one in a few months.

Day 285 - Aug 5, 2012 - Opening the first bottle

A few days ago, I opened one of the screw-top bottles of CWGA (Concord Wine Grape Adventure) wine. The wine was very clear; as clear as I’ve seen. This is encouraging because no fining agents were used; just months of bulk aging. The taste, however, still needs improvement. I don’t know all the wine-related adjectives but, bottom line, the taste was a little harsh. Much better than the last bottle, though. Not bad for 9 month old wine.


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