How to Cap Beer Bottles for Homebrew

Want to learn how to cap your homebrew bottles correctly? Learn how here, along with some tips on avoiding common capping mistakes.

HOW-TO

Mat Stuckey

8/27/20233 min read

black tinted glass bottle lot on brown and white wooden cabinet
black tinted glass bottle lot on brown and white wooden cabinet

How to Cap Beer Bottles for Homebrew

One of the final and most important steps when homebrewing beer is securely capping the bottles before conditioning and storage. Improperly applied bottle caps can lead to oxidation, lost carbonation, and contamination down the road. Taking the time to learn proper bottle capping techniques ensures your labours of love remain shelf stable and properly carbonated.

With a quality capping device, a little practice, and careful attention to detail, even beginner homebrewers can master flawless bottle capping. Follow this guide to start capping your bottles like a pro.

Selecting Bottle Capping Equipment

The first step is obtaining suitable equipment for applying bottle caps:

Cappers

Homebrew shops offer various bottle capper choices:

  • Two-handed cappers position on top of the bottle and use levers to crimp caps down. These provide maximum leverage for tight seals. Popular affordable options.

  • Single-handed cappers integrate the levers so one hand can crimp. Convenient for bottling assembly lines but require more hand strength.

  • Bench cappers securely mount to surfaces and use both hands to lower bottles onto an internal lever for crimping. Useful when bottling large batches.

Consider the batch sizes you typically brew and your workstation setup when selecting a reliable capper that fits your needs.

Caps

  • Use crown style beer caps sized to fit standard 12 oz beer bottles.

  • Purchase pre-sterilised caps or sterilise bulk caps yourself before use.

  • Match cap material to your bottle conditioning plans - plastic if conditioning more than 2-3 weeks, steel for quicker consumption.

Proper bottle cap equipment ensures you have the best tools for the job at hand.

Prepare Bottles for Capping

Before crimping on caps, prepare bottles following these steps:

  • Thoroughly clean bottles with brewing cleaner immediately after use to remove residue and film.

  • Soak used bottles in sanitiser like diluted StarSan prior to bottling day to sanitise.

  • On bottling day, drain excess sanitiser and position bottles upright to prevent pooling sanitiser that could inhibit carbonation.

  • Prior to filling, visually inspect each bottle for defects like cracks, chips, mould, or etching. Damaged bottles should be discarded.

Proper sanitation and quality control reduces the risk of problematic bottles down the road.

Filling Bottles Efficiently

Choose bottling methods allowing smooth filler while minimising oxygen introduction:

  • Bottling buckets with spigots allow controlled flow into bottles. Place the bottling bucket on the counter with a spigot over the bottling tray below.

  • Auto-syphons powered by gravity offer precise volume control when filling directly from a carboy or fermenter.

  • Filler wands attach to a hose for fast, efficient filling with adjustable shut-off control.

  • Counterpressure fillers purge bottles with CO2 during filling to reduce oxidation. Advanced but pristine fills.

Work in assembly line fashion - one person filling while the other caps. Share the tasks.

Executing Proper Bottle Capping Technique

Follow best practices when capping for reliable seals:

  • Check capper alignment - Center cappers properly on crown top with lever arms evenly spaced.

  • Keep bottle upright - Hold bottles vertically to prevent drips, overflow, or trapping air pockets.

  • Press firmly - Apply vigorous, even pressure when crimping caps down to compress seals tightly.

  • Listen for clicks - Complete crimping with 2 loud clicks signalling the cap snapped into place fully.

  • Avoid double-crimping - Crimp correctly on first attempts. Re-crimping already compressed caps can weaken seals.

  • Visually inspect caps - Ensure caps sit flush with no gaps visible between cap edges and bottle openings.

Take care capping each bottle correctly to reap properly carbonated and shelf-stable homebrew later. Don't rush it!

Troubleshooting Issues Crimping Caps

With practice, capping problems diminish. But if issues arise:

Leaking from caps

  • Clean bottle threads and cap rim areas to improve bind

  • Discard warp or inconsistently-sized caps

  • Check capper alignment over caps and apply maximum pressure

  • Supplement capper compression with thumb pressure on cap edges

Loose or raised caps

  • Discard any deformed or improperly sized caps

  • Use heavier duty steel caps suited for beer over soda caps

  • Ensure bottle openings are flat, not rounded or chipped

  • Listen for double click sound signalling complete compression

Cap falls off when opening

  • Crimp again applying firm pressure with complete lever motion

  • Ensure capper jaws align centred on caps

  • Wet bottle tops lightly to create vacuum seal as caps adhere

Proper equipment, care, and technique minimises problems for smoothly capped bottles.

Cap Bottles Correctly for Quality Homebrew

  • Always thoroughly sanitise bottles and caps before filling.

  • Fill bottles evenly, leaving ideal headspace below the neck.

  • Maintain bottles upright through crimping to prevent liquid from wetting seals.

  • Position capper squarely over caps and compress completely with firm force.

  • Visually inspect each cap to confirm proper flattened placement. Recrimp if any seem raised or cocked on the bottle.

  • When conditioning, test carbonation after 1 week. Recap underfilled bottles showing low carbonation.

Reap the Rewards of Proper Bottle Capping

Carbonated homebrew is only as good as the bottle seals containing it! Spending a little extra care on this final crucial bottling step ensures shelf-stable brews able to delight for weeks to come.

For reliable homebrew bottle cappers, jump over to Brewpedia's Essential Brewing Gear. The equipment there helps master flawless capping for your best homebrew yet. Get bottling!