Wine: Rhubarb, Batch 006

Spring is here and it's time for Humble Blogger to begin a batch of wine again so that it can clear and age over the busy summer months and be bottled in the Fall.  This time I'm making 6 gallons (23 liters) of rhubarb wine Batch 006.   I began making Batch 001 rhubarb wine in May of 1968, some 46 years ago!  I'm still trying to get a decent rhubarb wine.  This may be it.  In the photos below, I'm showing the process only and not the recipe to avoid getting over complicated.   I'll add photos to this post as the wine progresses.

15 pounds of rhubarb I purchased in June 2013 at a Farmer's Market in Maplewood, Minnesota (a northern suburb of St. Paul, MN) The rhubarb was grown in Afton, MN

Journal notes from my Batch 001 rhubarb wine started May 29, 1968 and this page shows extraction of juice on June 1, 1968

15 pounds of rhubarb (minus leaves) cut into 1 inch pieces, ready to be washed

15 pounds of rhubarb placed in "Hefty" Zip Lock Bags (3 pounds to a bag) and frozen for 9 months from June 2013 to March 2014.

15 pounds of frozen rhubarb placed inside a food-grade plastic pail for juice extraction.

I added 5 pounds of corn sugar (dextrose a.k.a.glucose) and 1 gallon of bottled Chippewa Spring Water (containing 50 ppm of sulfur dioxide from potassium metabisulfite and 3 grams of LD Carlson Pectic Enzyme powder) to the 15 pounds of frozen rhubarb to extract the juice. [Note that I usually just use table sugar for juice extraction, which is a disaccharide of glucose and the sweeter fructose. Yeast must convert sugar to the monosaccharides glucose and fructose before fermentation can start. To do so, the yeast excrete an enzyme called "invertase" and the splitting process happens extracellular to the yeast, whereas conversion of the monosaccharides to ethanol and carbon dioxide happens inside the yeast (intracellular ). Grapes and other fruits naturally have glucose and fructose in their juice. I thought that by using some dextrose (glucose) in this wine I would gain a head start for the "must" to begin fermenting]

2 days later, rhubarb pulp and extracted liquid is further crushed using Humble Blogger's "Ye Old Grape Stomper" made from an unfinished table leg from Home Depot. The crushing continued for an hour.

A stainless strainer resting on top of the pulp and juice made an easy task of scooping the juice with a glass measuring cup into an empty plastic gallon jug.

Two gallons were extracted immediately and another one gallon and 2/3 of a gallon were obtained by adding a gallon of the Chippewa Spring Water to the pulp, extracting it as shown above, then by placing the pulp into a "cheese cloth" nylon bag and squeezing the juice from the bag. I filled the container on the right with Chippewa Spring Water to get a full gallon and to make the total "juice" volume equal to four gallons.

Out of 15 pounds of rhubarb, 3 lb. 13 oz. of pulp remained. I dumped this into the trash, but it would be better served by going into a compost pile somewhere if only the ground was not still frozen!

I dumped the 4 gallons of rhubarb juice and 2 gallons of Chippewa Spring Water into my 9 gallon primary fermenter to make a 6 gallon Batch 006 of wine. (the fermenter is described elsewhere in this blog). Other ingredients included 5 more pounds of dextrose and 6 pounds of sugar which my specific gravity measurements called for to get a final alcohol content of 13% (by volume). Bentonite (to help clarify the wine), more pectic enzyme (to help remove pectin cloudiness), yeast nutrient (to feed the hungry yeasts), yeast energizer (to keep the yeasts happy) and tannin (for astringency) and finally, dry Red Star Premier Cuvee yeast shown pitched on top of the juice in this photo.

I screwed the Fermenter top closed at 3:50 pm on Wednesday 3/26/14. A clear plastic air-lock is fitted on top of the cover. It extends into the fermenter via a rubber stopper through a hole. I added 10 ml of a 50% water-50% glycerin and a bit of potassium metabisulfite solution to it. As the yeast consumes the sugar, ethanol and carbon dioxide are generated. The carbon dioxide escapes through the airlock which is connected to a long PVC tubing which goes through a hole in the wall, across the top of the garage ceiling and out the front of the garage to minimize odors inside the house. A digital thermometer is attached to the upper left of the fermenter to monitor temperature via a probe taped to the lower right side of the fermenter. A plastic draining faucet extends from the lower right of the tank and is located above the floor of the tank where the "lees" (sediment) collect during fermentation. It greatly simplifies the process of "racking" the newly fermented wine into a glass carboy for secondary fermentation. No lifting is necessary. Finally, the tank sits on a dark blue plastic piece containing heating coils to every-so-slightly boost the temperature of the "must" inside if needed.

Video of start of fermentation on Thursday 3/27/14, one day after pitching the yeast.  I'll add updates to this Blog post as the rhubarb wine progresses to bottling. [Note: It's hard for me to grasp (because I don't think of gasses as weighing too much) that out of the 16 pounds of sugar added, about 8 pounds of carbon dioxide will be evolved if the fermentation goes to completion!  This is because each  molecule of monosaccharide produces 1 molecule of ethanol (MW 46 g/mol) and 1 molecule of carbon dioxide (MW 44 g/mol)].   

The Finished Wine:   Humble Blogger skips ahead to the bottled Rhubarb wine Batch 006 which turned out not to have a red tint but rather golden yellow.  Click on the link  "Wine Old and New" to see a photo of three bottles at the bottom of the page.  These were bottled in March 2015 but have a "vintage date on the bottles of April 2014, the date of the first racking of the wine.  

The residual sugar in the wine measured at 0.4% (using "Clinitest" for sugar in blood).  I decided at the last minute before bottling that the Rhubarb wine should be sweeter so I added a calculated amount of natural sweetener "Stevia" which is 150 to 300 times sweeter than sugar in the form of Stevia dissolved in glycerin and water from Vitamin Shoppe.  I calculated I would be adding 1.5% sugar equivalent of Stevia bringing the total "sugar" content in the wire to 1.9%.  By adding unfermentable Stevia instead of sugar I would not need to add Potassium Sorbate preservative to prevent added sugar fermentation by any residual yeasts.  The decision to make the wine sweeter may not have been wise as it is a bit too sweet for me!!  It's a fine wine but I haven't given any out to friends as yet.