Bottling - to purge, or not to purge…

[verdot]

… that is the question. But safe to say purging with inert gas would be the preferred way to bottle.

However, this year I did not do this. I added 200ppm of k-meta before bottling based on the ph and mistakenly bottled without adding argon. Now I’m wondering with the standard fill level just above the bottle neck, will my wine be safe from oxygen from sulfite alone? I would hate to see some purple wine quickly turn to red.

Another thought, what was done in the past before gas became readily available? Were corks longer or fill levels higher, or is the threat of bottling oxidation just overblown?

Thanks everyone.

 

[winemaker81]

Based upon listening to others, the percentage of winemakers who purge with an inert gas is a tiny fraction of all winemakers. The threat of oxidation is WAY overblown.

I dose with 50 ppm and bottle with ullage at the base of the neck of a Bordeaux bottle. This is where the level is if I fill the bottle to the brim then pull the bottling cane out. I've done this with 1/2" and 3/4" corks, and noticed no difference.

Among the purposes of SO2 is to address O2. Sulfite combines with contaminants, rendering them harmless. This is why we keep dosing with sulfite, as it gets used up. If the wine is dosed with K-meta, there is not enough O2 in the ullage to be a danger.

You're doing with 200 ppm at bottling? That's 4 times the typical dosage. You are really overthinking this. Adding that much K-meta is not a danger, but conventional wisdom says it's unnecessary.

Try bottling a case with purging and one without. A year later blind taste them. I seriously doubt you'll taste any difference.

 

[Garagista]

Regarding the SO2 level at 200 ppm, a wine with that much free SO2 could not be sold or consumed in Europe. While the US has a limit of 350mg/l, the EU is 150mg/l. I know as home wine makers we don’t care but there is a reason for the limits on commercial wine and to me,. 200 borders on worriesome. I would cut it 50/50 with another wine before bottling. Just my .02.

 

[Rice_Guy]

* For where you are now, if you have had a week go by the oxygen in the ullage has reacted with chemicals in the wine and the batch is experiencing “bottle shock”. To open each bottle then flush would increase what is called total package oxygen.
* Flushing with argon is a mixing activity. With tools available at home we do half then quarter then eighth etc. commercial lines prefer liquid nitrogen, add a drop and it expands as it warms pushing out atmosphere, in three seconds the cap is applied.
My version of no oxygen is to pull -20 inches Hg and insert a synthetic cork. I don’t think it develops bottle shock but others in the club will produce wines that have lower total package oxygen that survives as well as mine.
* Natural cork will leak about 5 mg oxygen in year one. Remember the advice of stand upright two days. The cork expands and some excess pressure is released from a bottle. Synthetic can be manufactured to copy natural leakage or to be tight as .5 mg in year one.
* Wine with no leakage becomes reductive. This leads to the tools for letting a wine breathe before drinking. Some of the compounds that were reduced become oxidized again / taste normal.

From all the reports I have read home wine makers are wasting time flushing with argon. They would have more gain by reducing earlier oxygen pick up in whites (ex racking that splashes) and increasing tannin extraction in reds.

 

[verdot]

Thanks everyone. Sounds like the bottles will be fine and maybe I don’t need to bother with gas. I’ve seen bottling lines doing it so assumed it was a good idea.

As far as the k-meta, I think I got that ppm number wrong. I added .5 grams per gallon. The package states 1/4 tsp per 5 gallons, which isn’t the most accurate way to measure.

 

[MiBor]

I added 200ppm of k-meta before bottling based on the ph and mistakenly bottled without adding argon. Now I’m wondering with the standard fill level just above the bottle neck, will my wine be safe from oxygen from sulfite alone? I would hate to see some purple wine quickly turn to red.

I'm just curious, what pH did you measure in your wine to warrant a 200ppm SO2 addition?

I bottled a small batch of Cab a couple of years ago and didn't feel like measuring SO2. I added what would amount to 50ppm K-meta before transfer to bottles, and used an AIO-like vacuum bottling system. A month later I opened a bottle and it smelled like burnt match sticks. The smell would dissipate after decanting the wine for a couple of hours, but it bothered me enough to actually measure the SO2 in the wine with my A/O kit, and it was 165ppm. Based on that experience I now measure the SO2 in every single batch of wine I bottle.

I think that a 200ppm SO2 wine would be undrinkable for me. You may want to open a bottle and check for that, before gifting a bottle of that wine to someone else and getting unpleasant feedback.

 

[MiBor]

This chart gets posted often on this forum, but here it is again:

 

[winemaker81]

As far as the k-meta, I think I got that ppm number wrong. I added .5 grams per gallon. The package states 1/4 tsp per 5 gallons, which isn’t the most accurate way to measure.

Winemakers Academy says 1/4 tsp K-meta = 1.4 g. This is:

5 gallons -- 0.28 g
6 gallons -- 0.23 g

Depending on carboy size, adding 0.5 g/gallon produces about 100 ppm

With regards to K-meta additions, accuracy is overrated. The standard dosage is 1/4 tsp in 19 to 23 liters of wine, which is a wide variance. Additionally, the level of "contaminants" in the wine, e.g., things SO2 will combine with and eliminate, is totally unknown. Regardless of ho carefully anyone tries to determine the dosage (measure pH, etc.), it's still a guess.

My take on the "standard" dosage is that it's the result of many decades of practical experience.

I have experienced the burnt match smell twice that I can recall. In both instances I was treating H2S and added what amounted to a triple dose of K-meta over the period of 36 hours. That smell dissipated with time, although I skipped the next K-meta addition as the wine obviously had enough in it.

I bottled a small batch of Cab a couple of years ago and didn't feel like measuring SO2. I added what would amount to 50ppm K-meta before transfer to bottles, and used an AIO-like vacuum bottling system. A month later I opened a bottle and it smelled like burnt match sticks. The smell would dissipate after decanting the wine for a couple of hours, but it bothered me enough to actually measure the SO2 in the wine with my A/O kit, and it was 165ppm. Based on that experience I now measure the SO2 in every single batch of wine I bottle.

No offense intended, but to get 165 ppm the K-meta dosage had to be over 3 times normal. This is not necessarily in one addition, but could be several over time.

 

[TurkeyHollow]

My version of no oxygen is to pull -20 inches Hg and insert a synthetic cork.

@Rice_Guy , I'm curious as to the method you are able to pull a vacuum and insert a cork. Do you cork in an atmosphere? Can you elaborate on the setup (very interested)?

 

[Rice_Guy]

@Rice_Guy , I'm curious as to the method you are able to pull a vacuum and insert a cork. Do you cork in an atmosphere? Can you elaborate on the setup (very interested)?

View attachment 53335 I built a corking tool to do vacuum corking. The plunger is a hair longer and I am not compressing the ullage to 2 atmospheres of pressure, the corks always are flush or a hair low.

A chamber was created with PVC and silicone gaskets
Chamber is placed on the bottle
A cork is put in a cone
Vacuum is pulled
Cork is inserted

There are several mentions of this on WMT. Steve posted the article about it that was in Winemaker Magazine

 

[verdot]

I'm just curious, what pH did you measure in your wine to warrant a 200ppm SO2 addition?

I bottled a small batch of Cab a couple of years ago and didn't feel like measuring SO2. I added what would amount to 50ppm K-meta before transfer to bottles, and used an AIO-like vacuum bottling system. A month later I opened a bottle and it smelled like burnt match sticks. The smell would dissipate after decanting the wine for a couple of hours, but it bothered me enough to actually measure the SO2 in the wine with my A/O kit, and it was 165ppm. Based on that experience I now measure the SO2 in every single batch of wine I bottle.

I think that a 200ppm SO2 wine would be undrinkable for me. You may want to open a bottle and check for that, before gifting a bottle of that wine to someone else and getting unpleasant feedback.

My ph with this wine was 4.0. This was a wine I did with a few rows that I let hang longer than usual to see how extended hang time would turn out, but this is beyond the subject of the thread.

 

[distancerunner]

Purging:

A friend of mine was head winemaker at a local vineyard. Their semi-auto bottling line included a purge station. It was a very simple affair. At one end was a tank of nitrogen. Copper lines from there to a mount. The business end had a hose barb on which was mounted an old fashioned brass rinse valve. Valve upside down, bottle straight up, purge for a few seconds, and on to one of the four head fillers. I was envious.

But when I thought about it, do I really want to purge the bottles? A little bit of oxygen, especially since we are currently using synthetic corks, seems to be a good idea. The O2 in the ullage might make up for the lack of air exchange between cork and glass? Or not. Is it enough to oxidize the wine in the bottle? Doesn't make sense that it would.

In the end, we decided to skip purging. It's an extra step on bottling day. And though we aspire to making bottles that will age for more than five years, we're willing to take the risk.

 

[TurkeyHollow]

A chamber was created with PVC and silicone gaskets
Chamber is placed on the bottle
A cork is put in a cone
Vacuum is pulled
Cork is inserted

There are several mentions of this on WMT. Steve posted the article about it that was in Winemaker Magazine

Pretty cool!

 

[MiBor]

No offense intended, but to get 165 ppm the K-meta dosage had to be over 3 times normal. This is not necessarily in one addition, but could be several over time.

The SO2 level must have been really high but just under the threshold of being noticeable, around 110-120ppm to begin with. I think I must have added k-meta multiple times to the same carboy without thinking. If I would have checked the SO2 of that wine before bottling, I would have known not to add more. Lesson learned...

Try bottling a case with purging and one without. A year later blind taste them. I seriously doubt you'll taste any difference.

I have tried this in the past with a case of Syrah, with the hope of reducing the length of time the wine needed to get over bottle shock. I used an ArT wine preserving can and flushed the ullage space with argon for 5 seconds, right before inserting the cork.
I found that it made a difference and the wine was drinkable (giftable) after a week, but a year later the wine from same batch that was bottled with air in the ullage space tasted better than the argon flushed bottles. Waiting with patience for wine to evolve naturally always pays off, but it's a hard lesson to learn.

 

[Rice_Guy]

, ,,,A little bit of oxygen, especially since we are currently using synthetic corks, seems to be a good idea. The O2 in the ullage might make up for the lack of air

Synthetic corks are constructed to mimic natural cork oxygen exchange. The common grade is rated at 5 mg oxygen per year. The Reserva line is lower / for long term storage.
The AWRI did some oxygen vs closure work which encouraged most of that production area to switch to aluminum caps which are rated at under 0.1 mg per year. Perhaps you are more concerned about reductive flavor than necessary.

 

[winemanden]

Just occurred to me.
If Oxygen was a problem in a bottled wine, why would they suggest aerating red wine?

 

[winemaker81]

Just occurred to me.
If Oxygen was a problem in a bottled wine, why would they suggest aerating red wine?

It does sound bizarre, doesn't it?

Aerating a wine causes evaporation and oxidation. If there are noxious smells, such as sulfite, evaporation dispels the aromas quickly.

Oxidation softens tannin in the short term, making certain reds and very few whites more palatable. However, duration is the issue -- that same process continues until the wine is ruined. Aerate a red and it's good for hours. Leave that glass open until the following day, it's probably already browning

 

[distancerunner]

Synthetic corks are constructed to mimic natural cork oxygen exchange. The common grade is rated at 5 mg oxygen per year. The Reserva line is lower / for long term storage.
The AWRI did some oxygen vs closure work which encouraged most of that production area to switch to aluminum caps which are rated at under 0.1 mg per year. Perhaps you are more concerned about reductive flavor than necessary.

Thank you for this.

What are reductive flavors?

 

[Charles DeVier]

Many folks are allergic to sulfates, as is my wife. Any level of sulfate is too much. It is not a necessary ingredient in wine. If God wanted sulfates in the wine, it would be in the grapes.

 

[verdot]

Many folks are allergic to sulfates, as is my wife. Any level of sulfate is too much. It is not a necessary ingredient in wine. If God wanted sulfates in the wine, it would be in the grapes.

Unfortunately, he didn’t add enough YAN in my grapes so so2 and nitrogen were in my regimen.