Sealing your homebrew in bottles is the final step that locks in carbonation and protects your beer from outside air and contaminants. A bottle capper and the right caps are essential pieces of equipment that every homebrewer who bottles needs. The American Homebrewers Association includes both bottle caps and a bottle capper in its list of essential bottling equipment, alongside bottles, a bottling bucket, and a bottle filler. Understanding how these simple tools work and how to use them correctly will help you avoid flat beer, leaks, and infections.
What Bottle Caps and Cappers Do
In homebrewing, bottle caps are the small metal closures that seal the top of a glass beer bottle. The American Homebrewers Association’s equipment guide explains that you should purchase unused crown caps from a homebrew shop and make sure you are buying the correct size, because some larger bottles require larger caps. Caps are designed to be crimped onto the bottle’s lip by a capper, forming a tight seal that keeps carbon dioxide inside and oxygen and microorganisms outside.
A bottle capper is the tool that does the crimping. According to the same AHA equipment guide, a special device is needed to seal bottle caps. The guide notes that a basic twin-lever capper is typically used and will get the job done, but some homebrewers use bench-mounted cappers for speed and ease. Without a capper, you cannot properly seal a crown cap, and twist-off bottles are not recommended because they are difficult to seal airtight.
Types of Cappers
The two main styles of cappers you will encounter are hand cappers and bench cappers. A Zymurgy article on the joys of bottling describes the author’s experience with both. A basic metal two-lever hand capper can be unwieldy when operated by one person, and it may hold onto the bottle tightly after crimping, requiring force to disengage. The article also mentions a plastic, two-lever hand capper that was easier to use, with smoother crimping and releasing.
Bench cappers, on the other hand, are freestanding units that require only one hand to operate, leaving your other hand free to stabilize the bottle. The Zymurgy article points out that a bench capper’s action is smooth, and the lever requires very little force to crimp a cap properly. Bench cappers are also adjustable to fit a variety of bottle sizes, from small 8-ounce bottles up to 750-milliliter bottles. A bench capper can make the capping process faster and more comfortable, especially when bottling large batches.
Sanitizing Caps and Your Capper
Everything that touches your beer after the boil must be sanitized, and that includes bottle caps and the capper. The AHA’s all-extract homebrewing tutorial instructs brewers to cap bottles with sanitized caps using a sanitized bottle capper. The extract with specialty grains tutorial gives the same direction. This step is critical because any microorganism on a cap or the capper’s bell (the part that contacts the cap) could spoil the beer inside the bottle.
How you sanitize depends on the product you use. The AHA equipment guide mentions that homebrew-specific, no-rinse sanitizers are available, and that a bleach solution of 1 ounce per gallon of water can also be used, followed by a thorough rinse. The Zymurgy article highlights the convenience of a rinse-free sanitizer, noting that when diluted properly, it sanitizes surfaces by wetting them and letting them air dry, and because it is food-grade, a little residual moisture is not a concern. Always follow the manufacturer’s instructions on your sanitizer’s label for correct dilution and contact time. If you use bleach, remember that the rinse water itself can be a source of contamination, so a no-rinse sanitizer simplifies the process.
Caps can be sanitized by soaking them in sanitizer solution or by using a spray bottle to wet each cap just before capping. The capper’s bell should be wiped or sprayed with sanitizer as well. For more on preparing bottles and equipment, see our guide to bottle cleaning and our overview of homebrew sanitizers.
The Bottling Routine: Filling and Capping
Bottling day brings together several pieces of equipment. The AHA tutorials walk through a standard sequence that ends with capping. After fermentation is complete, you will mix a priming sugar solution into your beer in a bottling bucket, attach a bottle filler to the spigot, and fill each clean, sanitized bottle to the very rim of the neck. When you remove the bottle filler, the volume drops to about an inch from the top, leaving the right amount of headspace.
Once a bottle is filled, you immediately cap it. The all-extract tutorial says to carefully cap the bottles with sanitized caps using a sanitized bottle capper. The extract with specialty grains tutorial repeats the same instruction. Working quickly but carefully helps prevent airborne contaminants from settling into the open bottle. If you are using a hand capper, center the cap on the bottle mouth, place the capper over it, and press down firmly and evenly with both levers. With a bench capper, place the bottle on the base, set a cap on top, and pull the lever down in one smooth motion. The Zymurgy article notes that a bench capper’s one-handed operation makes it easier to keep the bottle steady and the cap aligned.
For a complete look at the equipment involved, visit our bottling equipment page. You can also explore the full range of homebrew bottles and the caps and cappers subcategory.
Bottle Conditioning After Capping
Once capped, the bottles need time to carbonate. The AHA tutorials state that you should place bottles in a room-temperature area, around 70°F (21.1°C), and let them sit to allow carbonation to take place. The yeast still in suspension will consume the priming sugar and produce carbon dioxide, which cannot escape the sealed bottle and dissolves into the beer. According to both the all-extract and extract with specialty grains tutorials, this conditioning period typically takes two to three weeks. After that, you can chill a bottle and enjoy the results.
During conditioning, keep bottles out of direct light and avoid disturbing them.
Safety and Handling Tips
While capping itself is a low-risk activity, a few safety practices will help your brew day go smoothly. Always use caps that are new and undamaged, as the AHA advises unused crown caps. The AHA equipment guide cautions against using twist-off bottles, as they are difficult to seal airtight, which could lead to leaks or lost carbonation.
When working with sanitizers, follow the label directions exactly. The AHA equipment guide notes that if you use a bleach solution, you must rinse thoroughly afterward. The Zymurgy article points out that rinse-free sanitizers eliminate the need for a rinse step and reduce the risk of contamination from rinse water. Never mix different cleaning or sanitizing products unless the manufacturer specifically states it is safe to do so. For broader safety information, see our article on homebrewing rules and safety.
Finally, keep your capper clean and dry between uses. Wipe down the bell and levers after each bottling session to prevent buildup of dried beer or sanitizer residue. A well-maintained capper will operate more smoothly and last longer.
Frequently asked questions
Do I need to sanitize bottle caps and the capper every time?
Yes. The AHA tutorials consistently state that caps should be sanitized and the capper should be sanitized before use. Any surface that contacts the beer or the bottle opening can introduce spoilage organisms, so sanitizing both is a standard step in the bottling process.
Can I use a hand capper for all bottle sizes?
Hand cappers work with standard longneck beer bottles, but some larger or unusually shaped bottles may not fit properly. The AHA equipment guide advises checking that you have the correct cap size for larger bottles. Bench cappers, as described in the Zymurgy article, are adjustable and can accommodate bottles from 8 ounces to 750 milliliters, making them more versatile for different bottle formats.
How long after capping can I drink the beer?
The AHA tutorials say to store bottles at room temperature, around 70°F (21.1°C), for two to three weeks to allow carbonation to develop. After that, the beer is ready to chill and drink. Some styles may benefit from additional aging, but the tutorials present two to three weeks as the typical conditioning window.
For more on the entire bottling and packaging process, visit our bottling and packaging section, or read the detailed guide on bottling and kegging homebrew safely.
