Bubbly or carbonated apple cider is a common phenomenon many people experience when making homemade apple cider. The bubbles are caused by natural fermentation, where the sugars in the apple juice get converted to alcohol and carbon dioxide by yeast. This is part of the normal process of turning apple juice into hard cider. However, you can take steps to control the amount of bubbles and still enjoy tasty sweet apple cider.
What causes bubbles in apple cider?
The main culprit behind bubbly apple cider is natural yeast. Apples have yeast naturally present on their skin. When you juice or blend apples, some of this yeast gets transferred into the juice. The yeast starts feeding on the natural sugars in the apple juice and undergoes fermentation. This fermentation process has two byproducts – alcohol and carbon dioxide gas. The carbon dioxide gets dissolved in the cider, which creates the bubbles.
In addition to natural yeast, a few other things can contribute to a bubbly cider:
- Using overripe apples – More ripe an apple, higher its sugar content. More sugar means more food for yeast, which leads to more fermentation.
- Warm temperatures – Yeast becomes more active in warmer conditions, so fermentation speeds up if cider is left out in room temperature.
- Adding extra sugar – Additional sugar, either in the form of apple juice concentrate or table sugar, feeds the yeast even more.
- Letting cider sit for too long – A long, slow fermentation allows yeast to produce more bubbles over time.
How can I enjoy sweet apple cider without bubbles?
Here are some tips to prevent or reduce bubbling in your apple cider:
- Use apples picked early in the season – Young, tart apples have less sugar content.
- Wash apples thoroughly before juicing – This removes some natural yeast from the skin.
- Do not let freshly pressed cider sit at room temp – Refrigerate it immediately to slow fermentation.
- Drink cider within 2 days – The bubbles will increase with time as the yeast keeps working.
- Avoid adding any sugar – Added sugar provides more food for the yeast.
- Pasteurize your cider – Heating briefly to 160°F kills the yeast and stops fermentation.
- Add preservatives – Potassium sorbate or sodium benzoate prevent yeast growth.
- Filter the cider – Filtering with a very fine mesh removes most yeast cells.
Out of these, pasteurization and preservatives are the most reliable ways. However, both will slightly change the flavor of your fresh apple cider. Refrigeration, early drinking, and avoiding sugar are simpler fixes that help minimize bubbles so you can enjoy the full apple taste.
How long does it take for apple cider to ferment?
The fermentation process that leads to bubbly cider can take anywhere from 2 days to several weeks, depending on these factors:
- Yeast levels – Cider with more natural yeast will ferment faster.
- Sugar content – More sugars equal faster yeast activity and fermentation.
- Temperature – Warmer temperatures accelerate fermentation by yeast.
- Preservatives – Preservatives slow down or prevent yeast growth and fermentation.
Under typical home conditions, natural yeast from apples will ferment cider in around 5-7 days. Refrigeration can slow this down to 7-14 days. Pastuerization or preservatives can stop the yeast and prevent fermentation altogether. So cider with no intervention will reach peak bubbly-ness within a week, but can be prevented from fermenting with proper storage.
Is it safe to drink slightly fermented apple cider?
In the early stages of fermentation, apple cider is safe to consume. Here is what happens at different levels of fermentation:
1-3 days
Minimal alcohol (less than 1%). Bubbles start to develop but cider still tastes sweet.
1 week
Alcohol around 1-3%. Noticeably bubbly, moderate sweetness.
2+ weeks
Alcohol above 4%, increasingly sour flavor. At this point it becomes true hard apple cider.
Consuming fresh apple cider that has started slightly fermenting is not hazardous if consumed in moderation. The small alcohol content and bubbles from generated carbon dioxide are not harmful. However, it may cause issues for people sensitive to yeast, alcohol, or carbonation.
Here are some signs that your cider has become too fermented to drink safely:
- Very strong carbonation that causes gushing when container is opened
- Sharp, vinegar-like smell
- Visible stringy strands or blobby patches of yeast
- Alcoholic taste similar to wine or beer
If your apple cider exhibits several of these signs, it is best to discard it instead of drinking. At that stage, the yeast has produced enough alcohol and carbon dioxide where consuming it may cause adverse health effects.
How can I control fermentation and prevent too many bubbles?
Here are some tips for controlling apple cider fermentation and avoiding over-bubbly cider:
1. Use less ripe apples
Young, firmer apples have less sugar content for yeast to feed on. This limits the potential for fermentation and bubbles.
2. Wash apples thoroughly
Wash and scrub apples with water before juicing to remove some of the natural yeast from the skin and limit what gets transferred to the juice.
3. Refrigerate immediately
Storing freshly pressed cider in the fridge prevents yeast activity and slows fermentation down to a crawl.
4. Drink within 3 days
Consuming the cider quickly gives less time for significant fermentation to happen.
5. Avoid adding sugar
Extra sugar feeds the yeast more, so leave it out to minimize their food source.
6. Pasteurize the cider
Heating briefly to 160°F kills off most yeast, stopping fermentation in its tracks.
7. Add preservatives
Potassium sorbate or sodium benzoate inhibit yeast growth and prevent fermentation.
8. Filter the cider
Filtering through a very fine cloth mesh or filter paper removes most yeast cells.
Using a combination of these methods, especially refrigeration, pasteurization, and preservatives, is the most reliable way to stop cider from becoming bubbly from fermentation.
Can I let apple cider ferment into alcohol on purpose?
Yes, you can intentionally ferment apple cider into an alcoholic hard cider if desired. Here is a summary of how to turn sweet cider into hard cider:
- Start with freshly pressed apple cider that has not been treated to prevent fermentation.
- Optionally add more sugar to increase alcohol content later. 1 cup sugar per 1 gallon cider adds about 1% alcohol.
- Add a cider or wine yeast strain according to package directions. This ensures complete fermentation.
- Pour into a fermentation vessel fitted with an airlock.
- Allow to ferment at room temperature for 1-2 weeks until bubbles subside.
- Transfer to bottles and condition for several weeks more to carbonate.
- Chill and enjoy your homemade hard cider!
With some simple equipment and ingredients, you can intentionally induce fermentation to turn sweet apple cider into a delicious bubbly hard cider alcoholic beverage.
Conclusion
Bubbles in apple cider are caused by natural yeast fermenting the sugars into alcohol and carbon dioxide. While bubbly cider is safe to drink at first, it will quickly turn into a true hard cider within a week or two if left unchecked. To enjoy sweet cider, control fermentation by refrigerating immediately, drinking within 2-3 days, washing apples to remove yeast, and avoiding sugar. Cider can also be intentionally fermented into an alcoholic beverage by encouraging the yeast activity. With some care and planning, you can enjoy apple cider in either its sweet fresh-pressed form or as an intentionally created hard cider.