It’s a little tough to tell from your letter which kind of screw-top bottles you’ve got so I’m not sure if you’re talking about what I would call screw top “sample bottles” or the kind of wine bottles you’d buy off the shelf in a wine shop. The former are best used for lab samples or as a temporary container for wine (and come in many shapes, sizes, and configurations) and the latter have their tops put on by a special machine on the bottling line. Sample glass bottles and their little plastic tops will never have the safe connectedness of a seal needed for long-term wine aging. Just one little bump or jostle and it’s possible that the top could start to unscrew and begin to let oxygen in. The quality control on sample glass also tends to be less than that for wine bottles for finished product, so I wouldn’t expect the glass to be blown, made, and measured for conformity at the factory like what I would call “final package” glass (glass ready to accept a cork or a screw cap). That means that there’s an increased likelihood of an inadequate seal between the glass lip and whichever stopper you’re trying to screw on.
In regards to the Stelvin™-type screw caps we see on commercial wine bottles, they require an expensive machine to put on correctly. I’ve heard of some folks re-using commercial screw-cap wine bottles for their finished wine. I don’t recommend this either as you’ll never get the same integrity of seal as you would with a professionally applied cap and the thinner glass neck on these bottles makes reuse dangerous when inserting or removing corks.
On the bright side, look up the Novatwist screw caps. They can be applied by hand, fit on standard Stelvin™-type bottles, and currently run at about $0.50 per unit at home winemaking shops. Unfortunately I can’t speak to their quality at this time since I don’t have experience with them.
But back to your question — can you just stick a cork in one of those threaded-top bottles (and maybe just buy a slightly larger diameter size)? Below are some things you should consider before you stick a cork in your screw-top bottle:
• Aesthetics — All right, this might be the most minor item on your priority list but there’s no doubt that a cork stuck into a screw-top bottle looks a little bit strange. It’s just not quite a traditional look shall we say? However, if the folks on your holiday gift list are into recycling and have slightly quirky tastes, you might just get away with it. If looks don’t bother you, then you may find the performance issues of why you may not want to put a cork in a screw-cap bottle a bit more compelling.
• Screw-top wine bottle necks can be more fragile — Even if the type of bottles you’re talking about aren’t in the cheap lab, sample-glass category, the top of any screw-cap bottle tends to be thinner and more fragile. This is related to how the bottle is made and its architecture; it’s made with less raw material and is just simply not made to withstand the downward and outward pressure of a compressed cork being forced into it. There’s not as much glass built around the neck and top of a screw-cap bottle and this becomes a safety concern as you might break some glass trying to fit it into your hand corker, especially if you have dry or stubborn corks, or when you are removing it with a corkscrew.
• Screw-top wine bottle neck configuration can be suboptimal for corks — Most screw-top wine bottles I’ve seen (like the ones I use to bottle my own commercial wines at Plata Wine Partners), whether Burgundy or Bordeaux shape, tend to flare out a little more below the neck than cork-ready traditional bottles do. That means that if you did manage to insert a cork without breaking the top or neck of the bottle, the inserted cork would flare out a little bit more at the bottom. Over time, this could lead to the cork being pulled down further into the wine bottle. Another QC issue is that cork-ready bottles are purposefully made with very straight sides and there is less “wobble” tolerance, which creates a better cork-to-bottle seal for the cork-ready bottle vs. the screw-cap bottle.
If you don’t want to use cork for some reason (maybe bottling up a delicate white wine or rosé which you don’t want or need any air to get into at all) you could always use sparkling wine bottles and a crown cap applier. Bottles and those caps should be pretty easy to get at your friendly neighborhood homebrew and winemaking supply shop or online. Aesthetically, I’ve seen plenty of good-looking homebrew and wine packages that look great with that jaunty little metal cap on top. Even some commercial wines, especially pét-nats or slightly fizzy rosés, are coming out in the marketplace in crown caps. Applying crown caps is super simple. You can buy (or presumably, rent) a special tool that clamps the metal caps down over the glass lip on the sparkling wine bottle. I’ve known winemakers to go this route when they really want to make sure their product doesn’t get oxidized prematurely and I would argue it’s a safer, more quality-conscious choice than bottling your wine into an ill-fitting bottle-to-closure combination.
I’m a huge fan of screw caps on wines, when done right, i.e., when the tops are purposefully bought and are applied on a high-quality bottling line. I’ve got years of pairing the right wines with the right screw-top closures and use them in my current wines.
In summary, I strongly recommend using cork-ready bottles if you want to use corks as your closures. And look into purchasing Novatwist closures if you want to use screw-cap bottles. I wouldn’t waste your time or risk your safety trying to find the “right” size of corks to smash in
