Simultaneous Primary & Carbing? Airlock + Balloon Idea

[BrewManChoo]

I started out with apple juice, bread yeast, and a balloon with one tiny hole. The flavor wasn't great, but I noticed it came out carbonated after only a week in primary, presumably due to the increased air pressure inside the fermenting bottle. The balloon was enough for the CO2 to escape, but only at a higher air pressure than with a standard airlock, which caused much of the CO2 to become suspended in the cider (i.e., carbonation).

Carbonated alcohol within a week!

So why not put a balloon (with one little hole) ON TOP of a standard airlock during primary? The airlock water would keep anything weird getting back into the beer/cider from the ambient air or from the rubber. But the balloon would also carb the brew during primary, because the pressure would have to be strong enough to get through the airlock water AND inflate a balloon enough to escape. And that pressure would result in more suspended CO2.

Are there any other fermentation gases than CO2 that we would NOT want suspended in our brew? Am I missing something? (And how would that different than adding priming sugar and carbing an enclosed bottle through controlled fermentation? Presumably all fermentation gases would be suspended in the brew there as well. Or does dextrose ferment out more cleanly than wort/must sugars?)

I am hoping for more than just conventional wisdom here. A lot of smart folks out there.

 

[MaryB]

Judging by some of the smells from airlocks I do not want those gasses trapped in my beer!

 

[Sadu]

I have my first pressure brew going at the moment - I use a pressure fermentor with a spunding valve to control the pressure. The drawcard for me is kegging/bottling a beer fully carbed at the end of fermentation. What you are talking about is somewhat more ghetto than this, but that is half the fun of brewing and I support your initiative

Now, I'm no expert so take what you will from this.

I wouldn't worry about those airlock smells - people ferment under pressure all the time, the yeast take care of it.

What is a concern is the amount of pressure - I have no idea how much pressure a balloon over an airlock can hold (not much), or how much pressure your carboy can take before exploding (hopefully the bung would pop out first). If you are fermenting in buckets, you don't have to worry about explosions but my bucket would leak at the tiniest hint of pressure and would not even get close to fully carbonated.

One thing you might consider is to buy a carbonation cap and spunding valve. Do your fermenting in a Coke bottle - I understand they make those pretty big in 'Murica. The Coke bottle you know will handle pressure. The spunding valve lets you control the amount of pressure whle it ferments. You generally want to start the fermentation with low pressure to keep the yeast happy and increase pressure towards the end when you need the carbonation. The spunding valve will let you know how much pressure you have so you should be able to judge the carbonation levels after a couple of brews.

When you ferment under pressure you can go a bit warmer than normal since the pressure supresses ester formation. This speeds up your fermentation and makes room temp lagers more achievable. You also don't need as much headspace - at 5psi my krauesen is under 1/2", at 0psi it expands to 4" - incredible to watch it grow when releasing pressure.

You also need to figure out what to do with the brew once it's done. One option is to just drink it and not worry about some yeast cake in your glass. Maybe if you ferment in a coke bottle, pour it into a jug leaving the yeast behind and drink in one sitting?
Most people would do a pressure transfer to a serving vessel, but that requires keg fittings and CO2, you are getting considerably less ghetto at this point.

 

[BrewManChoo]

thx Sadu. Very helpful! Here is a picture of my simple setup. It is holding some pressure, so hopefully it will have some decent carb from the fermenter.

 

[jmcquesten]

Here's another way to really ferment under pressure.

View attachment 1494706934250.jpg

 

[BrewManChoo]

whoa! right on!

 

[BrewManChoo]

This is about 15 hours into primary, using about half a yeast cake from the last batch. I am hoping the increased air pressure suppresses the krausen enough to not need my blowoff tube. So far so good. There is a tiny hole in the balloon, and it is a 5 gallon batch in a 7 gallon bucket.