So you’ve made a wine kit and it turned out all right but maybe it needs a bit more sugar to suit your palate. Recently Sam wrote in with this exact dilemma. He had made a wine kit per the instructions and everything turned out as it should have but the wine just wasn’t sweet enough for him and his wife.
Is It Possible to Back Sweeten a Wine Kit?
Yes, it is possible and it’s not all that difficult to do either. Some wine kits include an “F-Pack” or unfermented juice with is used as a back sweetener. However, if your kit did not include this you can still sweeten things up a bit.
Before any sweetener is added you’re going to need to stabilize your wine, otherwise you risk starting a second fermentation. This can be quite dangerous if said fermentation takes place after the wine has been bottled (boom).
To stabilize your wine you’ll need either potassium sorbate or a sterile filtration system. Sorbate is the lease expensive way to go but it is another additive and, in some wines after a couple of years in the bottle, it can result in off flavors. However, if you plan on consuming this wine within two years or so it probably won’t make a huge difference.
Sterile filtration systems are what the pros use and even though there are amateur units available they can be quite pricey when new. However, if you happen to have access to one you’ll want to filter the finished wine with a 0.45 micron filter pad. This is what’s known as a sterile filter pad because it is fine enough to remove single-celled organisms such as yeast and spoilage micro-organisms.
You should only ever run a wine through a sterile filter pad after it is perfectly clear. Otherwise your pads will clog immediately. Commercial wineries often filter their wines once or twice with coarser pads before passing it through a sterile filter.
Now that we’ve covered that here’s…
How to Back Sweeten a Wine Kit
Step 1: Ferment your wine all the way to completion.
It should be ready to bottle before back sweetening. This means it is still, degassed, and clear.
Step 2: Clean and sanitize your primary fermenter or another carboy.
Step 3: Measure out the required amount of potassium sorbate and toss it into the clean container from step 2.
I use L.D. Carlson Potassium Sorbate (affiliate link) and it calls for 1/2 teaspoon per gallon of wine. Be sure to check what your bottle says in case different manufacturers sell different sorbate concentrations.
To ensure that we don’t add too much or too little sorbate I would leave out any sorbate that the wine kit comes with and instead use only a sorbate that you purchase. Because we can’t be sure what the concentration of sorbate is and how much is included in the packet it is best to use a measured amount that has the correct dosage information printed on it.
By adding the sorbate before racking you are letting the flow of the wine mix it in. You’ll still want to stir it well but this can help get things mixing from the start.
Step 4: Rack your wine into the clean container with the sorbate.
This helps mix it in and gets your wine off any sediment in the old container. Because we have to stir so much we want to be sure that we’re not kicking up any old sediment that would leave the wine cloudy.
Step 5: Start mixing in your sweetener in small amounts.
Stir well between each addition as you don’t want to over do it. Once it’s in there you can’t remove it.You can use table sugar, unfermented juice (the same juice the wine is made from ideally), or honey. Table sugar will have the least impact on the flavor profile.To use sugar you should dissolve it in a small amount of water first so that it mixes in properly.
I recommend making this mixture as thick as you can to minimize the amount of water going into your wine. It is possible to add just plain sugar but you risk leaving a pile of it at the bottom.Be sure to taste the wine between each addition. Again, you don’t want to go too far because removing the sugar is not really an option.
Step 6: Bottle your wine as soon as it has reached the level of sweetness you like.
All that unfermented sugar will be quite appealing to spoilage micro-organisms so it’s best to get the wine under a cork as quickly as you can.
Other Back Sweetening Methods
After publishing the original version of this article several Winemaker’s Academy members sent in their preferred methods of back sweetening which I’d like to share here.
Gary suggests using artificial sweeteners to back sweeten a wine. Because these are not made from real sugar they are not fermentable by yeast. You can add these sweeteners without having to worry about stabilizing the wine with sorbate. Keep in mind that some artificial sweeteners may impart their own sweetener taste which may be different from natural sugar, however, in small amounts it may not have a big influence.
Along these lines Allan recommends using saccharin which is not a fermentable sweetener. You just sweeten to taste and you’re done.
Neil wrote in to recommend wine conditioner which is a mixture of sorbate and sugar. The idea is that when you add wine conditioner you’re adding both the sweetener and stabilizer at the same time. Here’s a great intro to using wine conditioner to sweeten up your wines from E. C. Kraus.
Photograph of wine by: fs999. Release under creative commons license: CC BY-NC-ND 2.0
What about using a sweetener Matt, they are non fermentable so would not require stabilising.
That’s a good point Gary. I didn’t mention non-fermentable sweeteners or wine conditioner. I’ll have to go back and include these two as well. Thanks for pointing that out Gary!
Hi Matt, Last fall I had bottled some Fredonia that was back sweetened. After bottling, some of the corks popped,so I uncorked all of the bottles into a clean carboy,and installed an airlock. When i re-bottle this wine, is there anything i can do to make sure the corks don’t pop?
Hi Lyle, sorry to hear about your corks. That’s a frustrating problem to have. My best advice is three fold.
First, make sure fermentation is really over. You can do this by taking two specific gravity readings a few days or even a week a part. If they’re the same fermentation is over, if not sugar is still being converted, likely very slowly at this point.
Second, make sure the wine has been properly degassed. Whether you use a degassing tool, vacuum, or just wait until the carbon dioxide has come out of suspension is up to you but you don’t want to bottle the wine with suspended CO2.
Lastly, if alcoholic fermentation is indeed over (as indicated by two subsequent specific gravity readings that are the same) and it still seems like carbon dioxide is being produced there’s a chance your wine could be going through malolactic fermentation or has been exposed to a spoilage micro-organism. Hopefully you’re not picking up any off flavors or aromas and we can rule this one out.
Most likely it’s just a matter of getting the CO2 out. Since it is in a carboy, running a degassing tool could be your ticket to keeping those corks in the bottle. Remember, CO2 comes out of suspension more readily at higher temperatures so if your wine is bottled cool and then stored in a warmer place you could build up pressure.
Let me know what you think is going on and we’ll figure out what to do. Cheers Lyle!