Bottle caps (technically called crown corks) were invented by William Painter in Baltimore in 1892. Bill is dead, of course, but his company, Crown Cork & Seal (now Crown Holdings) is now one of several companies that manufacture bottle crowns. A friend in the business once told us that if you add ‘em all up, there is more steel used in the manufacture of crowns than in automobiles these days. We haven’t verified that fact, but if true, it probably says more about modern auto manufacturing than it does about crowns.
Moving beyond trivia, there are three things everyone needs to know about bottle caps, whether they’re ordering stock crown or custom printed ones. Those three things are size, style, and liner.
Oh yeah…four things: you have to know what a “gross” is.
First, let’s talk about size. North American bottles take a 26 millimeter crown. Most European bottles take a 29 millimeter crown, although some continental European imports to the US use the 26mm crown. You probably figured out that there was some difference long ago when you couldn’t recap one of those green import bottles you refilled with homebrew. Here in the US and Canada, though, there’s no issue; 26mm is the standard for 12-oz, pint and bomber bottles. The only time you’re likely to run into a glitch is when you’re using a 750ml Belgian: they sometimes come onto our shores with those three extra millimeters. Robert was disappointed a couple of years ago when he found out that he couldn’t recap his Boulevard Smokestack empties without ordering special crowns and a new capper. But all of Atlas’s stock crowns are 26mm, and all our custom-printed crowns in the last few years have been 26mm. That being said, we can get our hands on 29mm crowns if you need them.
Next there’s style: twist-off or pry off. Twist-off crowns are actually universal; they can be used for pry-off bottles as well (we use them with our red butterfly capper when we homebrew—remember those days?). Pry-offs, however, cannot be used in twist-off applications. The difference between the two isn’t the size or shape; it’s the metal. Twist-off or universal crowns have a softer metal that drips the twist-off threads better. Why bother having separate pry-off caps, then? Ahem. . . we will evade the question with a bigger question: why do we have twist off caps in the first place? Bob and Doug will explain it to you:
Of course, in the 30 years since the McKenzie brothers bestowed order upon bottlecap chaos, things have changed: US industrial beers stick to twist off, but craft brewers generally run to pry-off (even Boulevard Brewery switched over from twist-off to pry-off a couple of years before it sold out to Duvel). And high-gravity beers are all the rage in the States. When we checked out the “the vendor” in Winnipeg a couple of weeks ago, it was clear that Americans have surpassed Canadians in the “big beer” race; now we’ve got more hot ones down here than you do up there (hosers)!
And now, back to work: just so you know, Atlas’s stock crowns are universal (pry-off or twist off), and our custom crowns can be ordered in either type. Same cost.
Finally, there’s the liner to consider: crowns by default come with a standard PVC or PVC-free liner on the inside which ensures a tight seal. Those liners are well-and-good; they’re great for most applications where the product will be consumed within a few weeks or months after production. Some brewers want an extra layer of defense against enemy oxygen, and so for a few cents per gross more, they order crowns with a special “oxygen barrier” or an “oxygen scavenger” liner. To oxygen barrier liner is made of a special plastic that has elastomers, polyisobutylene and polybutylene, and it substantially improves the seal to further impede oxygenation. The oxygen-scavenger liner actually absorbs some of the oxygen that sneaks into the headspace before it’s capped. They start absorbing oxygen as soon as they’re wet so if you do get them damp before bottling day, they quickly become engorged and can’t absorb any more. They’re great otherwise, but if you don’t keep the plastic bag liner closed and keep the box off the ground during storage, an oxygen scavenging liner might be all “used up” after absorbing some of the oxygen in our warehouse and in yours by the time the crown is crimped to your finished bottle. At Atlas, our stock crowns have historically had a standard PVC liner (because they’re universal, we can’t use PVC-free or oxygen barrier liners, which are both too hard for twist off applications), and right now we also stock a dull gold crown with an oxygen barrier liner. Our custom printed crowns are available with a PVC (twist off), PVC-free (pry off), an oxygen barrier (pry off) or an oxygen scavenger (pry off or twist off).
If you want to talk more about crowns, or any other packaging issues, give us a call. And if you want to talk about SCTV, the Great White North (f/k/a Kanadian Korner) and the latter careers of Rick Moranis and Dave Thomas, give us a call. But if you want to talk about the relative merits of Canadian and American craft brew, send us a two-four first and your phone number, eh?. After we’ve sampled a few we’ll give you a call and let you know what we think.
PS, a “gross” is a dozen dozen: 144. Crowns are sold by the gross: 70 gross (10,080 pieces) to the case, 2800 gross (403,200 crowns) to the typical 40-case pallet.