Bottle shock?

Bottle shock is one of those strange things that may be hard to believe in / appreciate until it happens to you. Of the 50 or so batches of wine I've done in the past several years, I've really only noticed bottle shock once. That once, the difference in taste / bouquet was enormous, and took several months to recover from. It's been over six months now, and the wine (a Brehm Orange Muscat) is now very nice.

I think most sources recommend waiting a month or more after bottling. It really depends on the wine -- my Orange Muscat didn't really recover for several months. On the other hand, most of the kit wines I bottle are just fine within days. I guess if you run into an instance of bottle shock, I'd recommend you give the wine 2 or 3 months (from bottling) until you try it again (assuming you have that much patience).

Doug

My experience is a different from Doug's. I find that I do have bottle shock fairly frequently. I taste the wine when I bottle it and then open a bottle several days latter and it tastes differnet. A month or two latter it usually tastes very simular to my memory of the original taste.

I don't know if I am correct but I attribute it to the pressure caused by bottling. You drive a cork into a bottle which compressis 2 inchs of air cpace down to about half an inch. This will put about 4 atmospheres of pressure on your wine. If you leave your bottles standing this pressure, and some of the air, should blead off. If you lay them down right away, it may not. My thoughts are that the pressure does something to the chemical compounds in the wine that may reverse itself over time after the pressure drops. If the pressure does not dorp, then it may not reverse itself. Any comments?

Ray

It's not the pressure, it's the oxygen hit the wine receives at bottling. This is why a lot of commercial wineries bottle under an inert gas.

Ben

My understanding is bottle shock is an oxygen shock, due to the relatively large air exposure during bottling. The corking plays a role too, in that some air is forced into wine under pressure. The pressure should even out no matter what position the bottles are left in - the reason to leave them standing for some days is to prevent the pressured air from forcing the cork out. So the pressure should even out in either case

... unless synthetic corks are used. Those seal right away and don't have to be kept on side during bottle aging. Which I guess is another argument that the pressure should not matter in the long run because with syntethic corks it doesn't even out.

Pp

Maybe I did not state my ideas (and they are that only) in the best way. I am suspicious that it is a combination of pressure and O2. The high pressure would force a much larger amount of O2 to go into solution which would then react with the wine differently thant the O2 in solution at only one atmospher.

Storing bottles upright or laying them down will effect pressure differently. If they are kept upright for several days the pressure will bleed out. If they are layed down immediately after bottling this will not happen. Air in the bottle must be incontact with the cork for the pressure to blead off. Several cc's of volume must escape to bleed off the pressure. If it is laying down and wine is in contact with the cork this cannot happen. If it did, you would see leakage. Gas will leak through passages in the cork and arround the glass that ligquid cannot pass.

Now to be honest, this does happen with natural cork but I am not sure it happens with synthetic.

Ray

glass that ligquid cannot pass.

Hi Ray,

I am not so sure about your statement.

I top-off about 200 barrels at the winery each month. I am always amazed to see that (1) tight barrels have developed a vacuum (~ minus 3 - 5 psi) and that (2) each barrel has lost a quart or two of wine.

It would seem that liquid leaves the barrels faster than the gas is replaced.

Regards, Lum Del Mar, California, USA

A very interesting observation, Lum. My comments were based on liquid/gas movement through permeable systems. This is something that I deal with all the time in the oil and gas industry. Gas, any gas, will easily pass through pores that liquid will not pass through at all. It is hard to get any liquid through a system that has 1 millidarcy of permeability while gas will readily flow through 0.001 millidarcy of permeability. What you are observing is probably someting very different and probably involves weatability of the wood and/or capillary action. I have heard of the negative pressure in barrels and fully believe you, but I had never thought of it in this light.

But I do not think that it is a factor with cork seals or we would note a drop in volume over several years of storing bottles on their side. Have you ever noted a lessening of volume in a wine bottle due to aging?

Ray

The wine volume in the bottle will go down over time, how much depends mostly on the storage conditions. I'm just reading a book on making wine cellars, and the author describes several experiments he made on this, for example, by heating the wine to 100F over several hours and then cooling back down. This resulted in an ullage increase - don't remember how much exactly but more than 1/4 in, basically equivalent to several years in his wine cellar.

His explanation was the heat forces the air in the bottle out, upon cooling the lost volume is replaced by air to even out the pressure.

Now that I think of it, I'm not sure if the wine was standing up or on the side for the experiment, but my wines that are stored on side in an appartment room show increasing ullage over time without signs of leaking.

Pp

How much time are you talking about? I have never noticed such ullage in bottled wine but then again, I have not stored for more than 5 years.

IMHO, It's usually in the 10 year and up range that the ullage in a bottle can start to be noticable. This has occured with bottles stored on their sides and in some cases even up side down. It can be very noticable when you get to the 30 or 40 year range. The strange thing is that different bottles stored under the exact same conditions can have significant differences in ullage even though there was no sign of leakage.

Andy

What the heck is ullage? I've been doing this for decades and this is a new term for me.....

Ullage in bottles is new to me. If the bottles are laying down on their sides and exhibit this, and certainly if we are talking about 10+ years they must be laying on thier side, then air can not be exiting the bottle as it is not in contact with the wine. This does not mean it is not happening, even if there is no sign of leakage. After all, oak barrels show significant ullage, real wine lose, even when no wine seaps through to the outside. It may well be an osmotic effect where fluid is pumped through the oak leaving behind the larger molecules that make up the wine. After all Cork is just a type of oak and if it happens in oak barrels it may well happen in corks.

Just thinking out loud.

Ray

gas > will readily flow through 0.001 millidarcy of permeability. What you are

thought > of it in this light.

I suspect capillary action is the driving force, and under the right conditions, capillary forces can be orders of magnitude stronger than diffusion forces.

Yes indeed. I have several dozen bottles of red wines with ages older than ten years. They are stored on their sides and they all show significant ullage. The level in a 1981, Stags Leap Cabernet is a centimeter below the shoulder of the bottle (and it's brown and it will be garbage. The only thing worse than drinking a wine too soon, is drinking one too late).

Lum Del Mar, California, USA

If you had been aging your wine in barrels, you would be aware of ullage. Ullage is the loss of volume of wine due to evaporation, diffusion or some other such processes. It is typical to have to top up barrels on a regular basis to avoid excess air space above the wine.

2-3 years in temperatures that vary between 68-80 over the year, with low humidity. Definitely not ideal storage conditions.

Pp

I'm just a home winemaker, not in quantities big enough to use barrels. Biggest carboy is only 25 litres. I'd been following the discussion of the loss of wine from barrels but you guys pulled a fast one on me. "Ullage"; I'll have to remember that one. :-) Thanks, Bob

So you guys are saying the wine is lost through the cork!? I regularly inspect the corks on my bottles and never see anything leaking out or even discolored. My wine is stored corked in 1.5 litre bottles, on their sides in a cabinet, for 3 years at most.

Well, Bob, I am just a home winemaker also and about 5 years ago I got a 10 gallon barrel. That was the best thing I did because I discovered I can not make a red wine to my style without barrel aging. I am not even satisfied using oak chips or powder and aging in glass. I am not a big fan of a lot of oak but there is a tremendous difference in mouth feel between wine aged in glass carboys and barrel aged wine. I now also have a 30 gallon barrel. You might be surprised at how your status as just a home winemaker might grow to become a "Tweener" - between amateur and micro winery - especially if your product keeps increasing in quality.

I have never noted ullage in bottles but I usually bulk age for up to 3 years and then only have it in bottles for 2 or 3 years. (I have some now that But not seeing leakage is not a sign that ullage is not happening. As Lum has commented, barrels may loose a bottle a month but it is not simple evaporation because it can pull a negative pressure. It must be going though the sides of the barrel. But you will not see any sign of leakage. No drips and no staining in good barrels. But it still happens. The same may be true of corks. You could have ullage and no staining.

Ray