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Bottle Carbonating

Bottle conditioning is the process of naturally carbonating beer by adding a priming solution (water + some type of sugar) to the flat beer immediately before bottling to initiate a “re-fermentation” in the bottle. The CO2 produced from the re-fermentation in the bottle is absorbed into the beer, creating carbonation. The amount of carbonation in the finished beer can be controlled by adjusting the amount of sugar in the priming solution. After priming and filling, the newly bottled beer should be stored at 70-75F for 2-3 weeks or until fully carbonated. After this time the bottles can be chilled or stored below 60 degrees to stabilize the beer.

Bottle conditioning also has an effect on the flavor and aroma of the beer due to the presence of active yeast in the bottle. The yeast in the bottle is able to reabsorb or process byproducts from fermentation eventually rounding out or mellowing the flavors. It can also extend the shelf life of beer by delaying the staling effects of oxidation.

Many different types of sugar can be used for bottle carbonation, including corn sugar (dextrose), table sugar (sucrose), or dry malt extract. In order to properly determine the amount of sugar to use, you need to take into account the temperature of the beer and the volume as well as the type of sugar and the level of carbonation desired. Northern Brewer’s Priming Sugar Calculator is a good resource for determining the amount of sugar to use.

When a batch of beer fails to carbonate in the bottle there are a few common causes. After fermentation the yeast cells that remain in solution may be too stressed or too few to re-start fermentation in the bottle. The likelihood of this happening increases with the length of secondary fermentation and the alcoholic strength of the beer. To ensure proper re-fermentation, additional yeast can be added to the beer at bottling. You can use a fresh pack of the original yeast or use a neutral fermenting dry yeast such as the Danstar Nottingham ale yeast (y005).

Another common cause for lack of fermentation is storing the bottles in too cool an environment during conditioning. At cooler temperatures the remaining yeast will not be able to re-start fermentation in the bottle. Make sure the bottles are stored above 65F until the beer is fully carbonated. Sometimes warming the bottles and rousing the yeast from the bottom of the bottle get the process started. If that doesn’t work you may have to resort to dosing each bottle with a small amount of dry yeast after opening and then recapping the bottles.

Forgetting to add priming sugar and not getting a good seal on the bottle with the cap can be other reasons for lack of carbonation in the bottle. The easiest solution to these problems is to dose each bottle with additional sugar. The best way to do this is to open each bottle and add the pre-measured conditioning tabs to each bottle. Only dose with more sugar if you are sure that you forgot to add priming sugar or that the caps had a bad seal, otherwise the extra sugar can result in too much carbonation.

For more information on Bottle Conditioning, see our Advanced Guide to Bottle Conditioning.

Getting Carbonation Right with Kegs

Carbonating your beer, cider, or soda in kegs can be simple, easy, and quick. There are a few things to know in advance, and a few different methods. This guide will go over them for you. Most carbonation in kegs is done using pressurized CO2 from a gas cylinder, a process called force carbonation. The fastest results can be achieved when the beer in the keg is at a cold temperature. This will let the CO2 diffuse into the beer more efficiently and at a faster rate.

The most accurate and easiest method for force carbonating is often referred to as the “set it and forget it method.” On page 2 of this document, select your refrigerator temperature and your desired carbonation rate, set your CO2 regulator to that pressure, and wait 5-10 days for the beer to carbonate.

A more accelerated method of force carbonation involves putting 30-40 PSI of CO2 into your chilled keg of beer, and shaking or rocking the keg to diffuse the gas at a faster rate. Depending on how cold your beer is, and how much you agitate the beer, you can have your beer carbonated in anywhere from 12 hours to 3 days. Once it is carbonated, dial your CO2 regulator down to serving pressure, and vent excess CO2 out of your keg. It is advised that you wait an hour or two for the beer to settle down before serving.

Another way to carbonate in kegs is with priming sugar, or any other fermentable sugar. For a 5 gallon batch, just go by the same amount of sugar that you would for a bottle conditioned batch, typically 5 ounces for priming sugar. This will take 2-3 weeks for carbonation.

For more information, read our Kegging Overview or watch this short video:

Balancing Draft Systems

Proper balancing of a draft system is key to excellent presentation and serving of your homemade and commercially produced beverages. The most common side effects of an unbalanced draft system are overly foamy pours or slow pours. Err on the side of too much restriction, as a slow pour is better than a foamy one. Proper balance is determined by the pressure your beer is at, and the resistance (in units of pounds of resistance per foot) on the system. Resistance is provided by a couple of variables; we will talk about the most prevalent, tubing and elevation change. We’ll assume a keg pressure of 12 PSI, you may want to change that based on your desired carbonation rate.

Most home draft systems use 3/16” ID vinyl beverage tubing, which has a restriction of 3 pounds per foot. To achieve balance with your beer at 12 PSI, use 4 feet of 3/16” tubing (4 feet x 3 PSI per foot = 12 pounds of total restriction). For beer at 15 PSI, you would use 5 feet of 3/16” tubing.

¼” tubing has a much lower restriction than 3/16”, at .85 pounds of restriction per foot. For beer at 12 PSI, it would take 14 feet of tubing to get the same amount of restriction that you would for 4 feet of 3/16.

Gravity has an important impact, the above examples do not take into account the affect of elevation change with your beer. One foot of upwards elevation change imparts a half pound of restriction. Going downwards decreases your restriction by .5 pound per foot. If your draft system goes up 6 feet before serving, and you had your keg at 12 PSI, you would need 10.5 feet of ¼” tubing. If you were going down 6 feet, you’d need 5 feet of 3/16” ID tubing.

A little bit of multiplication can save you a lot of trouble when all you want is a perfect pint from your taps. For further information, please visit www.draughtquality.org

Corking Belgian Bottles

When bottling certain styles of beer that require a higher-than-normal carbonation level it may be necessary to use heavy duty 750ml Belgian style bottles with corks and wire hoods. These bottles are the same style used by many Belgian beers such as Chimay. The equipment needed to do this is: 750ml Belgian Style bottles, Belgian beer corks, hooded wires, and an appropriate corker.

The type of corker you use is important because you will need to be able to adjust the depth of the plunger and be able to compress the larger cork: iris-style jaws and an adjustable plunger are required. The Portuguese Floor corker works great for Belgian bottles (and is a real workhorse for corking wine bottles as well).

The process for corking Belgian bottles is similar to corking wine bottles except that the cork only goes in about half-way – test-cork an empty bottle first to find the optimal depth setting on the plunger. You will need to first sanitize all of the equipment, bottles, etc., prepare and mix in a priming solution, and fill the bottles as normal. Then place a bottle on the corker platform, drop a cork into the iris chamber, and make sure that the plunger is set to the correct depth. Once it is corked you can apply the hooded wires by twisting the wire with your hand or use a wire tightener. As the beer carbonates the cork may mushroom further while being held in place by the wire. When opening the bottle the pressure from carbonation should allow you to pull the cork by hand.

Choosing the Correct Keg Parts

When working with used kegs, there are a number of different types of posts, valves, and disconnects available. It is important to select compatible hardware to ensure your kegs hold pressure.

There are two basic types of soda kegs: pin lock and ball lock kegs. Pin lock kegs are identifiable by the nubs or “pins” that stick out perpendicular to the posts. Northern Brewer only carries ball lock kegs, so that’s what this guide will discuss.

Once you have identified that you have ball lock kegs, the next thing you may want to identify is the type of posts you have on the keg. The posts are the round stainless steel fittings on top of the keg, on either side of the lid hatch, that accept disconnects. They screw on to the kegs, and they have a small, spring loaded poppet valve in the center which keeps the keg pressurized when not in use. Aside from o-rings, posts and post poppets are the most common items that need to be replaced.

All keg posts are designated for either gas or liquid. They can be distinguished by a horizontal notch around the base of the gas post – liquid posts do not have this notch. Type A posts have a very short, flat base which is either hex shaped or star shaped. Type B posts have a taller base which is also sometimes slimmer, requiring a ⅞” socket. If your posts fit this type of socket, you have type B posts. Type C posts are fairly rare; they have a large hex shaped base and include a plastic spacer inside the post, underneath the poppet. A quick internet search should help you determine the exact post type, if needed. The poppet valves on posts may need to be replaced if they are leaking or sticking.

All ball lock kegs accept universal ball lock disconnects. Gas disconnects can only be used on gas posts, and the same goes for liquid. To attach the disconnect, pull up on the collar at the bottom of the disconnect, snap it on the keg post by pushing down and twisting, and then release the collar to ensure it’s attached. When selecting your disconnects you can either choose ones with barbed fittings or threaded mfl fittings for keg tubing. MFL disconnects require an additional barbed swivel nut in order to be attached to tubing, but this makes it easier to disconnect and reattach tubing for cleaning. Barbed disconnects function just as well, but they require a little more elbow grease.

O-rings are the most common item on a keg that will need to be replaced. Old age can cause them to leak, or they may need to be replaced if they have absorbed odors from soda, wine, smoked beers, etc. The Used-Keg Seal Kit has all of the o-rings required for a ball lock soda keg. It is a good idea to purchase one of these with each keg, or at least to have some around when replacements are needed.