DIAM cork retailers and shelf life

I’m going to switch from natural to DIAM 10 corks for my garage project this year, however I can’t find a retailer that sells them in quantities less than 1000. Two questions for you guys:

  1. anyone have a favorite retailer that carries DIAM 10? Slim pickings on my Google search, all retailers I have no prior experience with.

  2. how long would you expect unused DIAM corks to last if stored relatively cool and air tight? At current production, it would take me about 3 years to go through 1000 corks.


I don’t know of any sources for smaller quantities of Diam corks. Regarding storage, I wouldn’t store them more than 1 year. The two issues with storing natural cork is maintaining the humidity of the cork, and preventing mold growth on the cork and esp inside the tiny recesses in the cork. A cork that has begun to dry out will lose some of it’s elasticity, and that’s the entire reason that corks are such good closures. And getting mold on corks can obviously cause bad things in the wine, including TCA (aka cork taint). Diam is slightly different from natural cork, but the same issues apply I believe.

Maintaining the hydration of the corks is done by keeping it in a sufficiently humid environment. Controlling mold growth is done by injecting sufur gas into the sealed bag of corks. This is done every couple of months ususally, I believe. Unfortunately, sulfur gas is something you won’t have access to, as it’s controlled. There might be (probably is?) a simpler solution…not sure what tho.

Instead, you might be able to sell the excess Diam corks that you won’t be using. Several/couple of months before you plan to bottle, I’d list the Diams for sale on the Wine Business Classifieds site (link below…or use other similar avenues), including the date you plan to get the corks. I’m assuming there are others out there that could use a small quantity of Diam10s. You’d have to hassle with selling/delivering the corks, but it completely eliminates the out-of-use storage problems.

Good luck!

Thanks for the advice Eric. Wouldn’t be a big deal if the retailers I found weren’t marking them up 2-3x. Hard to swallow throwing out $250-300 in corks.

On further research, it seems the DIAM 10’s might not allow for enough oxygen ingress and I should be aiming for something more like the DIAM 5. Then there’s the “traditional” vs “non-traditional” difference, whatever that is. Do you ITB get the low down on all this from your suppliers? The DIAM website sucks.

I went to the DIAM meeting last week. Pretty much a who’s who of winemakers there to check out the buzz. Very convincing arguments from Ramey and Chad Mellville. We are looking into them not so much for the TCA as we have had very few problems with our supplier, Lafitte. We are more interested in the ability to control bottle variation as that seems to be a much bigger issue. We are still concerned with the viewpoint that amalgamated corks look cheaper to high end consumers. I have to say that the firebrand versions do look nice AND the one I looked at closed a $375 burg so there is that.

AFA the number, it relates to the aging potential in years. 5=5 years 10=10 years etc. so you have to make a decision based on the type of wine you are making. Most folks are using 10s as far as I could tell. Also I understand that the # will dictate the length of the cork so lower = shorter.

With regards to keeping them, I’d contact the supplier and se if they can re-condition them like with other corks. I bet there are issues with doing this with DIAM but not sure. Also we usually gas the bags and tape them up till we can get them back to the supplier.

Not exactly DIAM, but I use Amorim Twin Tops. They have a thin layer of natural cork on each end. They quote taint rates around 1/1000, and I believe them. On our own wine, we went over 2 years between my wife and mom on white wines without a corked bottle.

They have been very good quality and good customer service.

The office is: (707) 224-6000

Vance Rose will help you. If you don’t get him through the office, his cell is: (707) 694-5909

I think you can order in small batches for each bottling run. That way, you don’t have to store your corks. That is ideal.

I am thinking of switching over to all twin tops, even for our reds. Have done some and they seem to be just as good and around .33 the price of the solid corks.

Im leaning toward Diams for my own wine. If I do Id be happy to sell you some at my cost. I’d very likely be using the 10s though.

Andrew, interesting looking product however this statement on their website is concerning to me: “It is ideal for fruity wines and recommended for wines not intended for long bottle ageing” (sic). I’d hate for the closure to dictate the life span of my wine.

Berry, that’s a very kind offer. Approximately when do you expect to bottle? I hope to do so in the next 2 months to free up barrel space and get it done before what looks to be another early harvest.

My suggestion is to talk with Vance. I think it depends on how much 02 gets in during bottle and several other factors. He can tell you about the 02 info on those compared to other options. I think it let’s in less air than solid cork and is more uniform. I also don’t think they are trying to sell the cheaper option. They’d rather you buy solid corks at 29 cents than twin tops at 11 cents.

He tells me that they have a new tech for eliminating it completely from solid corks too, but I don’t recall when that will roll out.

Regardless of where you get your corks from, he knows a lot about this whole area. Very nice guy too.

Not until the spring. Sorry.

Hi. Have you tried G3 Enterprises? 209 341 4045?

Rama will they not sell you a bag of unbranded Diams? They may require COD to do that but most will to get them in the hands of winemakers for trial runs. The minimums are often for branding purposes. I used them for 2 vintages on our whites. I used the Diam 5 which they stated breathed the closest to natural cork. I recall them saying the 10 was similar to a scewcap very, very, low O2 ingress and a very firm cork which you may have trouble getting into the bottles with a hand floor corker.

Overall I was happy with them but due to the minimum for branded corks I went back to natural. I did see some seepage up the cork after a few years in bottle. They have updated the coating to aid in preventing that so they say.

Its hard to store open bags for long. I have stored closed bags with good results and some will recondition them with humidity and so2. If you decide to store the partial bag keep it cool dark and 70% humidity, you know basically in your wine cellar.

Stephen, G3 was one of the places I found that only sells in quantities of 1000. Thanks though.

Joe, I did eventually hear from Francois, their US representative, and am hopeful we can work something out. Ideally I’ll do half my production under DIAM 5 and the other under DIAM 10. My own wines prior to 2012 were all made in glass carboy, which I think you could call very reductive. That has made them slow to come around but seems to have extended their drinking windows as well. Not sure if that’s analogous to using the DIAM 10’s, but if so I’d welcome it. There’s only so much of my own wine I’d want to drink over a giving time period! [cheers.gif]

Love Diam! I use them for a project I have in Spain–my supplier there told me to use them within a year.

I may be nuts, but have a feeling that many people that open the bottles may not realize it’s not a natural cork (looks similar enough they may not think twice)–that said I regretfully bought unnecessarily long, overly pretentious ones, and think the shorter ones may have a different looking finish (?).

Only complaint is that they’re a bit hard to put back in the bottle if you don’t finish the wine–well worth it for all the benefits though.

I had thought about the extra long version of the DIAMs, but they are already a little harder to pull than regular corks, and the really long ones would probably be even tougher. Plus, I presume that part of the reason is that they mate up to the neck of the bottle more securely than regular corks – obviating the main reason to go longer with regular corks.
One thing with the marketing of DIAMs is that they are a little unclear on what the various designations pertain to – rate of oxygen ingress or expected years of structural integrity. When I’ve asked the sales reps about this on a couple occasions, the answer has been “both” but I’ve gotten a whiff of salesperson “I don’t really know but I’ll just make something up” both times.


Funny you should say that.

I had the same feeling about the different year ratings. Clearly not exactly the same, but it reminded me of the time the contact lense sellers we busted for selling the same contacts as 2 day, 2 week and 4 week at different prices with different packaging.

DIAM was generous enough to ship me samples, so I’ll be bottling under both DIAM 5 and DIAM 10. Should be and interesting experiment.

Coincidentally, they were shipped by G3 Enterprises that Stephen mentioned earlier. Though it was on DIAM’s US representative’s request that they did so.

Hello Sir,

I am so sorry to revive this ancient thread but I WOULD LOVE to know the outcome! Have you tasted the wine that was bottled using the DIam 5 vs 10 - recently? We are seeing a fair amount of good wines going with Diam 5 corks and I am wondering if that really means MAX 5 years or MIN 5 years???

They’ve been nothing but reliable and as advertised. I haven’t had a bottle of either my wine or a commercially available one that was unexpected oxidized or otherwise flawed that could be attributed to the DIAM closure.

Based on my experience, the 5 and 10 are meant to be minimum values. If anything, the 10s took too long to develop. I had to sit on them a few years more than anticipated before they entered a good drinking window, and this was a pinot not some hard-nosed syrah!

1 Like