Lost carbonation after bottling from keg

Hey all.

Recently tried bottling from a keg for the first time, and now my previously well carbonated brew is flat.

Here's what I did:

Used the low tech racking cane attached to a picnic tap method, with a rubber stopper to control the flow into the bottle and let the air purge. I dialed down the CO2 from 12 to 5 psi to keep the foam down. Purged some air from the top of the keg a well. Bottling worked out fine then redialed back to 12. Couple days later took a pull from the tap. Nice head like before bottling, but it quickly subsided and there were virtually no bubbles in the brew. Did purging the keg do this? I assumed an adequate amount of CO2 had been absorbed by the beer and I was just releasing some of what was in the head space. Does the beer give the carbonation up when you purge.

Also. How long can I expect the carbonation to hold in the bottle using this method? Will I have to invest in a beer gun in the long term?

Thanks!

I usually use this method for bottling but I put my bottles in the freezer for a good chill before I fill them. The warm bottles will knock the carbonation out of solution in a hurry. YOu can also turn up your co2 a day or so before you bottle to offset any co2 you lose during bottling. I've had bottles last several months without losing carb. I've never had one go flat.

For the perceived problem with the keg, when you reduce head space pressure, the CO2 dissolved in the beer at the higher pressure will start to come out of solution. The pressure in the head space will rise while the dissolved CO2 in the beer will fall, eventually reaching equilibrium at a pressure somewhere below the starting point.

So, yes, if you turn off the CO2 feed to a keg and then purge the head space, the beer will be a bit "flatter" after some time. And the effect grows as the keg empties of beer, both due to the increased head space to fill and the reduced amount of beer to do the filling.

As for the bottles: assuming a good seal, what goes in is what comes out. As mentioned, chilling everything before starting will help (but do not frost the bottles!). A quick bottle rinse with some ice water from a trusted water source before filling will help as well.

Thinking about that, I wonder if some iced Star-San mix might be the Ultimate Solution for carbonated bottling: bottles chilled, sanitized and coated with a surfactant might really keep the CO2 dissolved in the beer...

Cheers!

There's no need to lower the pressure if you're using a stopper...chilled bottles, the stopper, and gentle bleeding out the pressure in the bottle should work well...just make sure to test the picnic taps ability to keep that tube on so it doesn't fly off when filling!

Good one. I'll try filling at the same pressure next time. After all I'm paying for that CO2 I'm letting escape.

Like that chilled StarSan idea too!

Thanks folks!

I used the chilled StarSan method with room temperature bottles last week with my CPBF, and it worked fine. I put my Vinator in the bottom of a 5 gallon bucket and dumped in about 1 1/4 or 1 1/2 gallons of cold StarSan - sanitized each bottle while the previous one was being filled and inverted it to drain for a few seconds. I used the bucket and a lot of StarSan because I wanted a lot of thermal mass due to each bottle warming up the StarSan a little. I guess the pH of the StarSan might be .1 or .2 higher at 35 or 40 ºF than at room temp. but should still be acid enough to sanitize. I did notice one weird thing - after I finished I poured the StarSan back into a gallon jug and noticed that it was cloudy. After a couple of days it hadn't cleared up - my pH meter showed the pH was still well under 3, so I assume it was still good, but tossed it anyway to be safe.

I only sanitized 33 bottles - if you do many more than that the StarSan might warm up too much and need to be replaced with cold StarSan.

EDIT: After further investigation, it seems that the StarSan turned cloudy because the bucket I used was one I had previously used to soak small parts in an OxiClean solution, so there was a white film on the inside of the bucket - mineral deposits, Oxi residue, or whatever. I didn't notice any off taste from the bottles I sanitized that way, but next time I'll use a clean bucket. On the bright side, the bottom 1/4 of my old bucket looks brand new.

day_trippr said:

For the perceived problem with the keg, when you reduce head space pressure, the CO2 dissolved in the beer at the higher pressure will start to come out of solution. The pressure in the head space will rise while the dissolved CO2 in the beer will fall, eventually reaching equilibrium at a pressure somewhere below the starting point.

So, yes, if you turn off the CO2 feed to a keg and then purge the head space, the beer will be a bit "flatter" after some time. And the effect grows as the keg empties of beer, both due to the increased head space to fill and the reduced amount of beer to do the filling.

As for the bottles: assuming a good seal, what goes in is what comes out. As mentioned, chilling everything before starting will help (but do not frost the bottles!). A quick bottle rinse with some ice water from a trusted water source before filling will help as well.

Thinking about that, I wonder if some iced Star-San mix might be the Ultimate Solution for carbonated bottling: bottles chilled, sanitized and coated with a surfactant might really keep the CO2 dissolved in the beer...

Cheers!

Click to expand...

Why not frost them? I haven't heard anything about that before.

A heavy frost will provide a bazillion nucleation sites to help CO2 break out of solution. Some people like the effect in their mugs, but bottling carbed beer is all about keeping CO2 dissolved...

Cheers!

Is there any negative effect to long term storage of beer using this method. Have a high gravity RIS that I plan on bottling this way.