Tutorial on Wine Making - Lesson 4 of 6
Wine Making Tutorial – Lesson 4 Secondary Fermentation
Wine Making – Secondary Fermentation of Wine
First of all, the term Secondary Fermentation is a bit misleading. In the dictionary the definition of fermentation is the anaerobic conversion of sugar to alcohol and carbon dioxide by yeast. Well, fermentation in almost all instances is complete at the end of Primary Fermentation. So what is Secondary Fermentation? It is when you transfer your wine out of your primary plastic fermenter usually to a glass carboy for a broad ranging period of time, depending on your wine and or wine recipe, for bulk aging, de-gassing, and multiple rackings to periodically remove sediment and solids from your wine. If you are adding oak you will be doing this during this stage also. Additionally, secondary fermentation should be attempted in as cool a part of the house as you can find. But remember, a steady temperature of 70 degrees is better than a temperature that swings from 55 to 70 throughout the course of the day..
If you are coming from Lesson 3 you now have wine from wine grapes sitting in your carboys or if you have made wine from fresh fruit or a wine kit you have wine that needs to be transferred from your primary fermenter to your carboy(s).
Some fruit wine recipes will simply have you pour your wine from your primary fermenter to your carboy, others will have you rack it with your racking cane or auto-siphon and tubing to leave your lees (solids) behind. Wine Kit instructions will direct you to transfer to your carboy by racking to leave sediment behind. Remember, wine making is part art and part science. Even though you are racking to eliminate the solids these same solids are adding flavor during the aging process… Again, part art and part science so there are no absolutes on how to do this, how often, how many times, etc.
With a wine kit your instructions will typically ask you to add Potassium Metabisulfite (preservative) and possibly Potassium Sorbate (stabilizer to prevent the restart of fermentation). Potassium Sorbate will typically be reserved for wines that will be sweetened before bottling.
In all instances when you will be racking to transfer off of and remove solids, be careful when moving your fermenter as not to stir your wine to mix and unsettle your lees (solids) from the bottom of your fermenter with your wine.
Most wine kit instructions, fruit wine recipes, and wine making books will have you rack your wine a total of three or four times. The time between each racking will vary tremendously as some wine kits can be bottled in just four to eight weeks, some wines from fruits in two to twelve months, and wines from wine grapes in eleven to eighteen months.
Topping Off of Carboys
Keeping your carboy full to minimize the amount of oxygen exposure to your wine is very important to minimize the chance of oxidization. Think of a cut open apple not wrapped or covered, it will turn brown. So will your wine if you have a 6 gallon carboy with only 5 gallons of wine in it with a gallon of air. There are lots of ways to deal with this, smaller carboys, multiple carboys, topping off with another similar wine, adding glass marbles, adding argon gas.
The purpose of degassing is to pull from your wine manually or mechanically trapped CO2 that if not allowed to dissipate naturally over time will result in bubbles for foaming when later uncorked from its bottle for consumption. If you are going to be aging your wine in your carboy for an extended amount of time, six to ten months, degassing is not all that critical as the CO2 trapped in your wine will work its way out of your wine and through the airlock on its own. However, with the expedited bottling and limited bulk aging schedule dictated by most Wine Kit instructions, degassing is incredibly important. Here is a link to some suggestions for degassing your wine.
Towards the end of your secondary fermentation and bulk aging is the time to add your oak granules, chips, cubes or staves. Here is a link to some ideas for adding oak to your wine and the timing of adding oak to your wine.
Wine Kits - Follow your wine kit instructions for adding sulfite. However, this should be in you’re your wine kit’s instructions but worth repeating, if you will be aging your wine made from a wine kit longer than six months you will need to give an extra dose of sulfite at the racking you do at or around your six month. This dose should be ¼ teaspoon which will be approximately 50 ppm. You could however do 10 to 20 ppm at each successive rackings with a final dose before bottling.
Wines from Wine Grapes – You can add 50 ppm at your first racking, skip sulfite at your second racking and add 10 – 20 ppm at each successive racking. Alternatively you can add 25 ppm at your first and second racking and 10 – 20 ppm at successive rackings.
Wines from Fruits – Most recipes for wines from fruits will have you add 1 campden tablet per gallon before fermentation and never make mention of it again. If you are going to be bottling in a couple of months an extra dose of 50 ppm should be added prior to bottling. If you are going to take up to a year to bottle you might want to follow the sulfite schedule mentioned above for wine from wine grapes.
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