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Vacuum in Fermenter

mjk0100

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I'm brewing a 6 gal. batch of Hofbrau lager. Fermentation calls for 7 days @ 62°F in primary, then drop to 46°F for 14 days secondary. I'm using a conical fermenter for both primary and secondary fermentation. For an airlock I run a 1/2" tube into a small bucket of sanitizing solution. A few days into the secondary the sanitizing solution had been sucked up into the conical!  :-[

Questions I have for whoever:
1) Has this happened to anyone else or, am I the only one on the planet who has experienced this?

2) If so, how do i keep it from happening again?

3) I use Starsanz to sanitize with. 2 quarts were sucked up into the beer. Is the beer safe to drink or do I dump it?  :-\

 
I use those S-shaped airlocks on the chance that temperature fluctuations create a vacuum in the fermentor. And I put 100 proof vodka in the things. It's sanitary, and won't harm the brew.

http://ecx.images-amazon.com/images/I/317DNT%2B1wfL._SY355_.jpg

As far as your Starsan beer goes, I'd pitch it.  :'(
 
Two quarts may have some flavor impact on your beer and may also lower the pH enough that it'll make it harder for the yeast to flocculate. Having that amount of liquid pulled into the fermenter also points to a lot of headspace in the fermenter.

The operative chemical in StarSan is phosphoric acid, plus a surfactant to make it foam. Phosphoric acid is perfectly consumable. It is a common mash adjustment tool, plus is a large part of most soft drinks.

To stop this from happening again, use a smaller amount of sanitizer as the airlock. If you use less than the volume of the tubing, you're good.

In fact, you don't actually need sanitizer. Plain old water will do. An airlock is a classic Pasteur S shape and works simply because nothing falls up. The water is there as a gas barrier so that the CO2 is trapped inside the fermenter and the beer won't oxidize.

 
mjk0100 said:
I'm brewing a 6 gal. batch of Hofbrau lager. Fermentation calls for 7 days @ 62°F in primary, then drop to 46°F for 14 days secondary. I'm using a conical fermenter for both primary and secondary fermentation. For an airlock I run a 1/2" tube into a small bucket of sanitizing solution. A few days into the secondary the sanitizing solution had been sucked up into the conical!  :-[

Questions I have for whoever:
1) Has this happened to anyone else or, am I the only one on the planet who has experienced this?

2) If so, how do i keep it from happening again?

3) I use Starsanz to sanitize with. 2 quarts were sucked up into the beer. Is the beer safe to drink or do I dump it?  :-\

1) yes
2)The blow-off tube doesn't need to reach more than a fraction of an inch below the surface of the liquid in the blow-off vessel. I use StarSan because if the air pressure changes - correction, WHEN the air pressure changes - the blow-off tube will suck up the liquid until it pulls the liquid level below the bottom of the tube. At that point air will be pulled in; when it bubbles through the StarSan muchof/most of/some of the bacteria in the air will be killed.
3) The beer will be safe to drink. Let it finish. If it doesn't taste bad at that point, it's good. If the beer is harsh/tart try an eighth of a teaspoon of baking soda in a glass of beer and see if that fixes it.

That's an odd fermentation schedule for a lager. I routinely start my lager fermentations at about 45 - 50F, then push it up to 60 to finish. I've fermented at the same schedule you used (by accident) and gotten decent beer, but I think it's safer to start low then warm it up to finish. What yeast did you use?
 
Thank you for the replies. Perfect, submerging the tube beyond its volume is a forehead slapper. I'll see this batch through and, I'll brew this beer again. The recipe is from a German site but, I'll step the temperature down a couple degrees per day until I reach target temperature. Again, thank you!  :)
 
Sorry, i didnt answer your question regarding the yeast. I used Munich Lallemand. Secondary is done this Sunday so I'm looking forward to giving it a taste then.
 
Yes this happened to me but not near the extreme you experienced. I have a 25 gal fermenter using a blow off tube like you, and when I brewed only 10 gals of lager, I noticed the fluid coming up the tube but never went in the fermenter, close though.  I believe this was due to the large head space and when the gases condensed it caused a vacuum.  Ales are no problem as the temp is higher, but lagers are cooler temps as you know and now brew 15 gals min for the lagers and no probs sense.  So, recommend bigger batches.
 
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