Back Sweetening Hard Cider
Cider is hot! And I don’t mean the winter-time beverage of heated apple juice with cinnamon in it. No, the cider we are discussing here is that moderately alcoholic beverage also known as hard cider to distinguish it from the product that comes in a juice box. Hobby cider making is booming as both homebrewers and home winemakers find lots of familiar territory when they ferment some apple juice. If you start with apples, you need to grind or shred the fruit, then press it to extract the juice. You can also make perfectly enjoyable cider from commercial bottled apple juice. Pasteurized or sterile juice is fine, just check to make sure it contains no preservatives, like sorbate, that might inhibit your yeast.
Cider is produced in four basic styles. It is dry or sweet, and it is still or sparkling. To make dry cider, ensure sound fermentation conditions, use healthy yeast and adequate nutrients, and you should finish the fermentation with a residual sugar level of 0.4 °Brix (1.0015) or less. Cider makers, like winemakers, tend to use the Brix scale (percent sugar by weight) more often than the Specific Gravity or Plato scales commonly used by brewers. At 0.4 °Brix or below, a cider will taste somewhere between bone-dry and slightly off-dry and has little or no risk of spontaneous refermentation. To bottle such a cider as a still (non-sparkling) beverage, add sulfite like a winemaker or mead maker and bottle your cider under a cork in a wine bottle or under a crown cap in a beer bottle. For dry sparkling cider, do not make a final sulfite addition but instead add priming sugar just as you do for priming homebrew and bottle in pressure-tolerant bottles (with thick-walled glass).
Many cider drinkers prefer a bit of sweetness in their cider. Making a sweet cider at home is a bit trickier than a dry cider and that is where this article’s discussion comes in. There are some cider making techniques that preserve a fraction of the original sugar to achieve a noticeable residual sweetness. They are discussed briefly later in this story, but tend to be rather complicated and not 100% reliable. Most makers of sweet cider at home will want to use the alternate technique known as back-sweetening: The addition of a sweetener close to bottling.
Cider Sweetness
Apples naturally contain several different sugars. One academic study reported the following sugars (in g/100 mL, nearly the same as Brix or percent): glucose 0.9–3.2, fructose 6.6-9.6, sucrose .8-5.5, and total sugars 11-16. The ratio of various sugars influences the perceived sweetness. That is because human tasters do not experience these sugars equally on a gram-to-gram basis. Researchers have used tasting panels to help determine “iso-sweet” levels — the concentrations of various sugars that taste equally sweet. Using a solution of 10% sucrose as a reference, they found that an 8% solution of fructose was equally sweet. On the other hand, glucose required an 18% solution for the same effect. Sucrose is common table sugar (usually cane or beet) and glucose is readily available in homebrew supply stores as corn sugar or dextrose. Although fructose has a greater sweetness impact for its weight, it is not easily found in commercial retail sales. In a low pH beverage like cider sweetened with sucrose, over a period of weeks the sucrose will “invert” to an evenly divided combination of glucose and fructose. Since fructose is sweeter than sucrose but glucose is less sweet, the resulting effect on the flavor is not pronounced (the “inverted” result will be about 90% as sweet as a pure sucrose version).
Sucrose is the most common sugar for back-sweetening. Since it is fermentable, adding it to a finished cider risks refermentation and pushed-out corks or blown-up bottles. Cider can be also be sweetened with a non-fermentable sweetener such as saccharin or stevia, which we will cover later in this article. You have three major choices to make when you sweeten a cider: Which sweetener to use, how much to add, and how to assure a stable product. Among the fermentable sweeteners, dry sucrose comes in a number of forms:
• Cane sugar. Refined white sugar from the juice of sugar cane. Imparts sweetness to cider with very little additional flavor.
• Beet sugar. From sugar beets; a direct substitute for cane sugar.
• Brown sugar. Cane sugar with residual molasses content. For commercial brown sugar, the molasses is added to refined white sugar. For raw sugar, some molasses is left in the sugar by only partially refining it. Brown sugar adds flavors of caramel or molasses and will influence the taste of your cider beyond sweetness.
Other fermentable sweeteners include honey, which is about 77% sugar and will impart honey flavor. Maple syrup is about 66% sugar with a distinctive aroma and flavor. Molasses is about 55% sugar and has a very distinctive brown-sugar type flavor and aroma. Agave syrup, from the same plant used for tequila, is about 70% sugar. It is high in fructose and has a stronger sweetening effect for a given addition.
Cider may also be sweetened with sweet apple juice. For your own sweetener, you can freeze some juice at harvest and then thaw it, boil it briefly to sanitize, and add. Use your starting Brix number for your sugar calculation. Commercial apple juice is usually about 12 °Brix (1.048 SG). If you wish to minimize dilution of your finished cider but want to stay with apples, you can sweeten with apple juice concentrate. The commercial product is usually about 70% sugar.
Your next decision, then, is how much to sweeten your cider. As noted earlier, below about 0.4 °Brix (1.002 SG), your cider will be perceived as dry. In cider competitions, sugar levels from that level up to about 0.9 °Brix (1.003 SG) are considered off-dry. From 1–4 °Brix (1.004–1.016 SG) is considered medium to medium-sweet, and greater than 4 °Brix (1.016 SG) is considered sweet cider. To find out what you like best, run a trial on a small amount of cider and then scale up your batch when you find a taste you like. Weigh out enough of your chosen sweetener to equal 50 g of sugar. Dissolve that in distilled water and dilute in a beaker or cylinder to 100 mL. You now have a solution that contains 0.5 g of sugar in every mL. To treat a tasting sample, measure 100 mL of your finished cider. If you add 2 mL of your test solution, that will be 1 g of sugar and you have sweetened to the 1% level. Try 4 and 6 mL in additional samples for 2% and 3%. Once you know the percent that you like, you can treat the whole batch. For instance, if you like a 2% sugar level and you have 5 gallons (19 L) of cider, convert the 19 L to mL: 19,000 mL. Multiply by your chosen decimal sweetness fraction (2% = 0.02) to determine grams to add:
19,000 mL x 0.02 = 380 g of sugar
Table 1 (below) presents the grams of various sweeteners needed to make a trial solution that is 0.5 g/mL (50% sugar) and the amount of sweetener needed to produce a 1% sweetening in 5 gallons (19 L).
Note: With the apple juice Brix around 12 (1.048 SG), you cannot make a 50% trial solution with it. To determine the amount of juice to add directly to a 100 mL sample for a 1% addition, divide 100 by the Brix reading. For example, 100/12 = 8.3 mL of juice in a 100 mL sample.
Non-fermentable Sweeteners
So far, our discussion has been all about fermentable sugars. An alternative to sweeten without the risk of refermentation is to use non-fermentable sweeteners. The ones used in cider making are the artificial sweeteners sucralose (marketed as Splenda) and saccharin, plus the natural plant extract stevia. Sucralose is about 300 to 1,000 times as sweet as sucrose and saccharin is about half that. For Figure 2 (at the bottom of this page), I have assumed a factor of 600 for sucralose and 300 for saccharin. Stevia is marketed as a powdered concentrate and as a liquid concentrate. Both the powder and the liquid are about 50 times as sweet as sucrose. The table presents the preparation of 100 mL of trial solution that mimics the “50% solution” in the first table. Also presented is the gram weight needed for a 1% “sucrose equivalent” sweetness in 5 gallons (19 L). Note that these figures are for the pure artificial sweeteners and the stevia concentrates. Some commercial sweeteners are diluted with dextrins or other materials to make measuring them easier in everyday use. If you buy one of those, check with the manufacturer for the sucrose equivalent.
While very efficient, the artificial sweeteners and stevia yield mixed results in terms of flavor and mouthfeel, with some tasters finding that they dislike cider sweetened with one of these products. Since I have not used them, I turned to some colleagues who have for their experiences. Jennifer Harris, founder and director of Sonoma County’s Farm to Fermentation Festival in Sonoma County, California, has had good success with stevia in ciders. She used the liquid extract and first tried 4 mL in a 5-gallon (19 L) batch. She reports that the sweetness was noticeable but some tasters (including herself) detected an objectionable stevia flavor at that level. On another batch, she used 2 mL instead and found a slight sweetness with no stevia flavor. She estimated the apparent sweetness as about like a 0.8% to 1.0% residual sugar, which correlates reasonably well with the table at the bottom of this page.
Kimi Anderson is a former associate of mine at The Beverage People homebrew supply store in Santa Rosa, California, who now lives in Maryland. She experimented with stevia liquid concentrate in cider, adding just one drop to a 2.5 gallon (9 L) batch. At that level, none of the tasters (including me) detected any stevia flavor, but the sweetness was also very low. Anderson describes it as just enough to take the edge off of a dry cider, but suggests some other methods to improve cider flavor that will be discussed in a moment.
After you have chosen your sweetener and decided the amount to add, you may treat the batch. If you are using dry sugar, boil it with an equal amount of water to sanitize for a few minutes. For the liquid syrups, you may add sterile commercial products directly. If in doubt, add enough water to thin to a boilable consistency and boil first as for dry sugar. To make a still sweet cider, rack it into a bottling bucket and add the sugar. Stir in potassium sorbate at a rate of 0.5 to 1.0 g/L. Add sulfite to about 30 mg/L and bottle. Sparkling sweet cider is difficult to produce at home. If you are set on it, your best bet is to sweeten, add sorbate, and add sulfite as just described and then force carbonate in a stainless steel soda syrup keg as you would with homebrew. For bottles, you can use a counter-pressure filler. Some users report that sorbate-stabilized ciders produce sediment during aging. To avoid that, you could sweeten and sorbate in bulk and store for a period in a topped-up carboy, but preventing spoilage becomes a challenge once sugar is present.
To use an unfermentable sweetener, just add it to the cider in the bottling bucket. For still cider, sulfite as described earlier and bottle. For sparkling cider, add priming sugar to the bottling bucket along with the sweetener. Do not add any sulfite. Bottle the cider and keep it at room temperature for a week to ten days for the residual yeast to ferment the priming sugar to carbonation. Sweetness will come entirely from the added sweetener, as the priming sugar will be consumed by the yeast.
Other Processes
For traditional cider making, there are a couple of other processes to produce a sweet cider. One of these is called keeving, where a combination of pomace and calcium rises to the top of the cider to make a crust. Because much of the yeast is in the crust and the cider below is deprived of nutrients, the fermentation may become “stuck” and leave a naturally sweet cider. Counting on achieving a stuck fermentation at the right sweetness is risky at home.
In another method, partly fermented cider is chilled and sterile filtered to remove any residual yeast. Sterile filtration is also difficult to achieve at home as the equipment is costly.
Some hard ciders are bottled sweet, with or without carbonation, and heat-treated to pasteurize the cider and prevent refermentation. I have seen no guidelines for this process at home.
Finally, cider may be bottled in thick-walled Champagne bottles under crown caps and allowed to carbonate. Then, the “méthode traditionnelle” for sparkling wine is employed. The way this works is that the bottles are held upside down and moved every day (“riddled”) to move residual yeast into the neck. After a period of riddling, the neck is frozen in a brine bath, the cap is removed, and the block of frozen cider containing the yeast blows out. At that point, a sugar syrup can be added, the bottle topped up from another open bottle, and a Champagne cork inserted into the bottle. If all the yeast was removed, you are left with a shelf-stable sweetened sparkling cider. This process is not recommended for first-time cider makers, however, as the contents under pressure can be dangerous. If you want to try and use this method, read up about making sparkling wine, and get some advice from someone who has mastered the technique. Brew Your Own’s sister magazine, WineMaker, has covered this process, which you can read more about by visiting http://winemakermag.com/story480.
Along with the various sweetening alternatives, Kimi Anderson noted that many cider makers would be happy with getting more “apple” character in their hard cider or just taking the edge off of the dryness. She has experimented with yeast choice and has found some strains, like M2 from Enoferm and M02 from Mangrove Jack’s, leave a slight impression of sweetness without leaving enough sugar to cause instability. She has also found that using white wine specialized yeast nutrients like OptiMum White® from Lallemand can help preserve and enhance fruit aromas. Those nutrients do not replace your usual nutrient program and are usually applied at a rate of 1 g per gallon (3.8 L) of juice. For the sometimes bland results that may result from using bottled apple juice, Anderson has added white wine tannin products to enhance mouthfeel and fill out mid-palate body. She has had good results with Scott’Tan FT Blanc Soft from Scott Laboratories. At a rate of 7.5 g in 5 gallons (19 L), she found character reminiscent of the skin tannins one encounters on eating a fresh apple. It was a bit strong for her and she intends to use just 4 to 5 grams next time. For sweetness, she used sucrose at 1.5% and applied sorbate. She also added one more product that is used in winemaking to give a slight impression of sweetness and improve mouthfeel: Gum Arabic. As a 25% liquid preparation, such as Flashgum R Liquide from Scott, it is used at a rate of 1.5 to 5 mL per gallon (3.8 L) and is the last product added in the bottling bucket. Anderson reports very positive responses from a variety of cider tasters with the overall character being a slightly sweet with a very “appley” cider.
Ask a cider maker (or a winemaker)
As you may have noticed, making and sweetening cider relies less on homebrewing techniques and more on home winemaking skills. If you want to get good at making hard cider, chances are your local homebrew shop has someone on staff who is the go-to winemaking person — find out who they are and ask for advice. You can also talk to meadmaking friends about their techniques as they also often use back sweetening methods. Give some of these techniques a try, and have some fun making cider this season!
