Fermentation Headspace - Can You Have Too Much?

[Bmd2k1]

Wondering if you can have too much headspace in a vessel during fermentation? ie) say you are doing a 100 gal batch in a 200 gal or 300 gal vessel - for example -- do you risk issues?

I realize open fermentations are done -- and then at some point put under airlock.

I guess the key is to make sure whatever CO2 is generated, needs to be sufficient to fill the headspace -- and protect the wine.


Cheers!

 

[winemaker81]

Not as far as I know

 

[barryjo]

Wondering if you can have too much headspace in a vessel during fermentation? ie) say you are doing a 100 gal batch in a 200 gal or 300 gal vessel - for example -- do you risk issues?

I realize open fermentations are done -- and then at some point put under airlock.

I guess the key is to make sure whatever CO2 is generated, needs to be sufficient to fill the headspace -- and protect the wine.


Cheers!

I was my understanding that less headsspace was needed because the airlocks couldn't handle wider fluctuations in air pressure. Airlocks are generally used when fermentation decreases. With 100 gal in a 200 gal vessel, I would make a larger airlock. Some tubing, a stopper to hold the tubing and a 4-6 oz jar should do the trick. I would use water and inexpensive vodka in the jar. If going for bulk aging, I would use glycerine. No evaporation.

 

[winemaker81]

Airlocks are generally used when fermentation decreases.

Not necessarily, reds are often fermented to completion, and some folks do EM so the wine is in the container longer.

However, if doing EM, I'd feel better with less headspace.

Now I ferment 4 lug batches in 32 gallon Brutes, so the container is only 20% to 25% full.

 

[Raptor99]

Wondering if you can have too much headspace in a vessel during fermentation? ie) say you are doing a 100 gal batch in a 200 gal or 300 gal vessel - for example -- do you risk issues?

During initial fermentation the yeast need oxygen, so headspace is not an issue. Once the SG is below 1.010, many of us rack into a carboy and put on an airlock. Before that point there is no need for an airlock. Many of us ferment in a food grade bucket covered by a towel. It's a lot easier to punch down the fruit cap and stir twice a day in a bucket.

I don't do 100 gal. batches, so I'm not sure how this scales up to larger batches.

 

[Rice_Guy]

@Bmd2k1 head space depends;
* surface area if you are the local winery and fermenting in 24” tall plastic skids you oxygenate more than if you are in a 36” Brute that is half full
* what are you fermenting, a wine which is high tannin as red grape or bitter apple has more redox buffering si it is less critical. As Bryan pointed out skins form a cap and you need space. My current black currant with cocoa powder is foaming badly, I have also seen Maurivin B yeast foam filling 1/3 of a Big Mouth, commercial yeast generally don’t foam.
Are you fermenting a kit which is pretty well filtered so it doesn’t gain with space.
* where in the fermentation are you? In exponential growth you need oxygen. My club mentor suggested whites should be racked at 1/3 sugar (1.050) to oxygenate one last time and then kept under air lock. A logic answer is that prior to alcohol producing metabolism it really doesn’t matter. You are farming in a way to grow happy yeast and once the yeast population is there anaerobic farming to make tasty alcohol. Of course a high tannin is an antioxidant with different goals as extraction.
* what kind of shelf life do you want, oxidation is cumulative ie if you spend a lot of redox potential in a primary you don’t have it when the wine is two or five years old, If you want contest winning shelf life you will minimize all oxygen.
* what is practical, what hardware do you own. Every winery faces the question of I have pressed NN liters of juice, what tank do I have open? ,,, and then make it work in a way to have happy yeast and maintain redox potential of the soup.

 

[Rice_Guy]

As I got caught in this rabbit hole, I found the following diagram and study. Thank you @Raptor99 for this information. Immensely helpful! I took the information from the study you cited and added the phases to the top of the below study. I believe that they are counting cells as being present, even if not alive, which is why the death phase does not show a decline in cell numbers.

View attachment 96883

Main phases of wine fermentation. Evolution of the main fermentation parameters during wine fermentation on a synthetic medium containing 200 g/L-1 glucose/fructose and 330 mg/L-1 assimilable nitrogen, with the commercial wine strain EC1118 at 24°C. Dark blue: fermentation rate; light blue: ethanol; red: cell number; green: nitrogen; and purple: sugars.

Marsit, Souhir & Dequin, Sylvie. (2015). Diversity and adaptive evolution of Saccharomyces wine yeast: A review. FEMS yeast research. 15. 10.1093/femsyr/fov067.

 

[Hazelemere]

Wondering if you can have too much headspace in a vessel during fermentation? ie) say you are doing a 100 gal batch in a 200 gal or 300 gal vessel - for example -- do you risk issues?

I realize open fermentations are done -- and then at some point put under airlock.

I guess the key is to make sure whatever CO2 is generated, needs to be sufficient to fill the headspace -- and protect the wine.


Cheers!

no risk