Hard Cider Tip #17C: Understanding Carbonation (Method Part 3 of 3)

This is the third part in my three part tip on developing your method for making hard cider. My focus is on the process versus the ingredients. I will highlight ingredients, but my goal is to help you understand the processes involved in making a hard cider that you enjoy. In Part 1, I highlighted the three top areas that can shape how you make your hard cider. Those areas are Sweetness, Flavor, and Carbonation and I went into detail about how Sweetness can impact your process. In Part 2, I covered the Flavor area and how it can impact your method for making hard cider. For Part 3, we will discuss how carbonation can impact your method for making hard cider.

Carbonation:

Legally, some countries define the level of carbonation a hard cider can have before its no longer considered a cider. For example, the U.S. only allows ciders to have 0.63 grams of CO2 per milliliter, which is just over 3.2 volumes of CO2. It’s doesn’t mean you can’t make them but if you put that much CO2 into your hard cider, you would be taxed like wine instead of hard cider. A carbonation level of 3.2 volumes would be considered sparkling. While there are different views, let’s consider the following ranges.

Volumes CO2 by Hard Cider Style

Still	Petillant	Sparkling
0-1.0	1.0-2.5	>2.5

You may be asking yourself, what does 1.0 or 2.5 volumes CO2 actually mean. Volumes CO2 is a unitless number that defines the volumetric amount of CO2 suspended in 1 volume of that liquid. Saying a hard cider has 2.5 volumes CO2 means you have 2.5 liters of CO2 per every liter of hard cider. It also means that same Cider has 2.5 gallons of CO2 per gallon of hard cider. If you removed all the CO2 from a liter of hard cider, it would fill 2.5 liters. Here is a quick table that approximates how sugar relates to alcohol and C02.

Specific Gravity	Sugar grams/liter	Sugar grams/gallon	Potential ABV	Volumes CO2
0.001	2.6	9.8	0.13%	0.6

When measuring the sugar in your juice, each 0.001 point of specific gravity reading means you have 2.6 grams of sugar per liter (9.8 grams per gallon) that could generate 0.13% alcohol by volume (ABV) and 0.6 volumes CO2 for the volume of juice you have. If you have 1 liter, you would generate 0.6 liters of CO2 or 0.6 volumes if you kept it suspended in the hard cider. If you had 10 liters of juice, you would generate a total of 6 liters of CO2 but still have 0.6 volumes. The same is true in gallons. For example, a batch of 5 gallons (19 liters) with a specific gravity reading of 1.050 fermented to 1.000 would generate over 150 gallons of CO2 during the process or over 30 volumes CO2 (50 points * 0.6 volumes * 5 gallon = 150 gallons / 5 gallons = 30 volumes). That’s a lot of airlock bubbles.

Let’s explore how the three carbonation levels could impact your method and equipment for making hard cider.

Still Hard Cider:

When you ferment your hard cider, it will naturally retain around 0.85 volumes of CO2. This is an estimate based at sea level and 68F (20C). If you are warmer or higher, that number goes down and colder or lower elevation, it goes up. Also, if you degas your hard cider, it will go down. So to make a still hard cider, you really don’t need to do much. It will naturally have some CO2 in it. There is no equipment needed. However, carbonation can help accentuate elements of a hard cider. It can help bring out aromas and I find it even helps balance an acidic hard cider. If you decide you want carbonation, you will most likely move into the pettilant region.

Petillant :

Pettilant is really where you find most beers and ales. You will get a nice little hiss when you open the bottle and some CO2 release when you pour it. When you drink it the carbonation is there, but you have to search it out. It borders on subtle and helps to cleanse your palate. It’s also where many commercial hard ciders are packaged. The question is how to achieve it. There are really two main options, bottle conditioning and force-carbonation.

Bottle conditioning is the process of adding small amounts of sugar, known as priming sugar, to your hard cider right before you bottle. This sugar is fermented by the active yeast still in your cider creating CO2. Remember you are adding to the 0.85 volumes already in it and instead of releasing to the atmosphere, you are keeping it trapped and suspended in the hard cider. The bottles once packaged, usually take 1-2 weeks at 68F (20C) to fully process the priming sugar and create the CO2. This requires yeast to be active so you can’t use sulfites and sorbates if you are bottle conditioning.

You don’t need a lot of equipment (check out The Shop for recommendations on some) but you do need bottles or packages that can be pressurized. This is usually bottles that can be crown capped or that have flip tops to seal in the CO2. If you use crown cap bottles, you will need a bottle capper and crown caps (see below.) You can purchase these through Amazon or a fermentation shop. Remember that not all crown caps are the same. You will find 26mm and 29mm caps. The 26mm are often called US bottles and the 29mm European but I have gotten both sizes in the US and Europe on bottles. Usually the 29mm is found of sparkling bottles where the 26mm is on more petillant bottles. That is not 100% accurate but it’s directionally correct.

The other means of achieving petillant carbonation is by force-carbonating. This is where you pressurize your hard cider in a keg or tank and force CO2 into it. As I describe in my book, this is all about pressure and temperature. The colder you can make your hard cider, the easier you can force CO2 into it. Kegs are a great way home hard cider makers can do this process. But this also requires a kegging system (CO2 tank, regulator, and lines). In addition, you will most likely want a counter-pressure bottle filler. Also, you will probably want the bottles, caps, and capper. You could simply serve from the keg but that can make sharing with friends challenging unless they have a keg system too. Force-carbonating is a step that quickly leads to a lot more equipment.

Sparkling:

Sparkling really isn’t much different from petillant from a process standpoint. You will still need to either bottle condition or force-carbonate your hard cider to make it sparkling. It is simply the level to which you carbonate it. However, that is where it can impact your process and equipment. It is also why you need to take care. Standard 12 ounce (355ml) beer bottles that you find in America are not made for sparkling drinks. They are made for petillant beer. You can probably use them up to 3.0 volumes but if you start going above that, you risk breakage. I’m not saying they will break. You just need to understand the potential risk. When you make sparkling hard cider, you really should use a bottle for champagne or sparkling wines. Remember, the US government would consider anything over 3.2 volumes to be wine and I would recommend treating it as a sparkling wine.

There are a bunch of different bottles out there. Weight and glass thickness are good indicators, but you still should investigate the rating on the bottle if you intend to use it for your sparkling hard cider. You are definitely better being safe when it comes to bottles than sorry. You can find bottles on Amazon but it is mostly beer and flip-top bottles. I recommend searching fermentation shops or even bottle suppliers for more varieties. If you are like me and enjoy trying hard ciders, you can also get a wide collection by recycling your trials.

Besides the bottle, you also need to consider the closure you will use. Crown caps work well for pettilant, but if you start making a lot of sparkling hard ciders with high CO2 levels, you might want to consider using champagne corks with wire basket retainers. This will help to ensure the CO2 doesn’t leak and the crown cap doesn’t become a projectile. Amazon and fermentation shops will have a variety of closures including 26mm and 29mm crown caps as well as corks.

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I have mentioned fermentation shops and Amazon during this series of posts. If Amazon is available, I assume you know how to access that. However, if you are in the US and wondering about fermentation shops I would suggest you checkout the following. Note: I’m not endorsing or getting anything from these places. I just provide them as resources to you.

• Local Brew Shop: There is a good chance you have a local fermentation or brew shop. I would encourage you to get acquainted with them. Besides being a great source for supplies, they can often provide advice. Mine is called BrewYourOwnBrew.
  
• Great Fermentations: This is the only shop I’ve found with clear 12 ounce beer bottles by the case. Here is the link.
  
• Austin Home Brew: If my local shop doesn’t have it, I usually have good luck finding it at Austin Home Brew Supply. You can check them out here.

For those in other countries, please leave comments with links to your favorite fermentation shops. I would love to have a reference list for others. You might be surprised by the number of people from all over the world that visit PricklyCider.com. I know I was.

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