# Air Tight Fermenter?



## junior06 (27/12/05)

Hi there...

i dont seem to have a completely airtight fermenter, the water in the airlock has remained level for a few days(brewed on the 23rd) no bubbles in the airlock and when i squeze the fermenter, the water level in the airlock seems to level, from this and basic physics the fermenter obviously isn't airtight...

although my gravity is dropping normally???
should i through this on down the drain????


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## Gout (27/12/05)

I wouldn't stress to much, i ferment with the lid loose sometimes, and others have fermented open.

I heard it was good to have no pressure on the brewing beer (on brew board or somewhere)

If you are still worried, you can put a small bit of food grade lube on the "O" ring of the lid, thats often the problem and it makes it easy to undo the lid also.

dont throw the beer out, she will be fine!


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## barfridge (27/12/05)

One of my fermenters has never sealed properly, and it always produces semi drinkable brews, but that's more down to the brewer than his tools.


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## dirk (27/12/05)

one of my fermenters doesn't seal that well, so far there is no problems with the beer. last time i had a problem i replaced both seals which fixedthe problem for a while

cheers
Dirk


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## pint of lager (27/12/05)

So long as you keep the bugs and dust out of your beer, it will be fine without a completely sealed fermenter.

Make sure you use your hydrometer tojudge when it is finished. Two-three days at the samr sg means it is finished.


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## fifteenbeerslater (28/12/05)

I think you will find everyone who has a large screw lid fermenter has had that problem once in a while. I now use fermenters with a very small screw lid which gives me a positive seal everytime. You could also make up a lever tool which would make the lid easier to open and close.
Cheers :beer:


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## Screwtop (28/12/05)

A quick check of the size of the airlock hole in the lid of your fermenter might help. Two of my fermenters have 13mm holes the other 3 have 12mm. Always had this prob and tried many of the suggestions above thinking it was the O ring or lid seal. After suspecting grommets and changing them without results I checked the hole diameter. Now use the two piece airlocks in these as the shaft is a little thicker and gives a good seal. Prefer the three piece airlock when I can get them as the shaft is tapered, so the further in the grommet it is shoved the tighter the seal. Found that the fermenter O ring seals satisfactorily with just a little pressure and most of the problem was the grommet not sealing properly. The fermenter lid really does not need to be tightened so much and is then easily removed.


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## fifteenbeerslater (28/12/05)

Another way around the problem of a grommet hole being too big is to wrap one or two turns of electrical tape around to airlock shaft to increase the diameter and then twist that int the grommet-works WELL as a QUICK fix. Sugest you renew the tape each time.
CHEERS :beer:


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## Ross (28/12/05)

As Gout correctly inferred - Getting your yeast to force CO2 through the airlock is not good anyway - I only tighten my lids enough to keep bugs out - Only had one airlock bubble in the last 6 months & that was a 7% Vanilla porter that was on steriods  ...
Tight lids cause nothing but headaches, trying to re-open them...

Cheers Ross...


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## ruserious (28/12/05)

i havn't had a _seal_ problem since i switched to the 'pail' type fermenter.

easier to clean as well imo, no 'o' ring in the lid to worry about and easy transfer of the wort due to the larger opening.

:beer: 
ruserious


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## Screwtop (28/12/05)

that was a 7% Vanilla porter that was on steriods


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## junior06 (28/12/05)

Hey guys..

thanks for the help i'm glad i don't have to throw out this one, cause i was looking forward to it, tasted not bad tonight, fermentation has completed?

i've heard its good to keep the beer in the fermenter for around a week or so before bottling, but because my fermenter isn't airtight will this cause oxidisation? should i bottle ASAP or will i still benefit from leaving it in the fermenter?


cheers
junior


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## Screwtop (28/12/05)

Not sure about a week or two! When it is finished (same SG for two consecutive readings) rack it! This assists in producing a clear beer. Pop it back into the ferm fridge for a few days (time up to you), when clear rack it again to a sanitised vessel (fermenter) primed with sugar/dex solution for bulk priming, then bottle from there. Dead simple priming, clear beer, bit more work cleaning sanitising fermenters etc, but well worth it!


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## NRB (28/12/05)

Screwtop said:


> Not sure about a week or two!



Why not? The yeast are still cleaning up all the unwanted byproducts.


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## Linz (28/12/05)

Junior,

If you've got a 2nd fermenter ..get it ready and transfer the beer. Its going to top out at 43oC later this week around Sydney, so get that beer off the yeast cake, or make sure that puppy is really cool (18oC)


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## junior06 (29/12/05)

Thanks again lads...

now if i dont have the option of racking or a fermenting fridge....

should i just bottle now?

cheers

andre


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## sosman (29/12/05)

junior06 said:


> i dont seem to have a completely airtight fermenter, the water in the airlock has remained level for a few days(brewed on the 23rd) no bubbles in the airlock and when i squeze the fermenter, the water level in the airlock seems to level, from this and basic physics the fermenter obviously isn't airtight...
> 
> although my gravity is dropping normally???
> should i through this on down the drain????
> [post="99593"][/post]​


I don't even bother to screw mine on anymore. The airlock is there only to plug the hole made for it (although I must say the outlet of my chiller fits nicely through there so the hole+grommet still serves a purpose).


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## Screwtop (29/12/05)

NRB said:


> Screwtop said:
> 
> 
> > Not sure about a week or two!
> ...



:blink: ?? Yeast fermentation produces by-products Ie: Alcohol, Co2, dead and dormant yeast cells etc: Microbe proliferation is inhibited (last fermentation phase) when increasing acidity, high temp, Co2 or alcohol levels reach a piont where the particular strain can no longer survive. There may still be sugar/fermentables available in the wort.


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## NRB (29/12/05)

Screwtop, in a perfect world under perfect circumstances with 100% efficient yeast, true, fermentation will equal alcohol and CO2. Unfortunately this utopia doesn't exists.

Several by-products are produced during the 'initial' fermentation which are later 'cleaned up' by 'secondary' & 'tertiary' fermentation as well as maturation/conditioning phases. These products may be fusel alcohols which are later esterified. Diacetyl is another fermentation by-product, unwanted in most styles. It is usually produced during early fermentation stages, but is again cleaned up as the yeasts absorb it later on.

Bottling after one week would result in more than just a so-called green beer, but would possibly contain yeasty, butterscotchy, acetaldehyde green apple flavours. This is all removed during the conditioning phase, which is why I always leave my beer alone for a minimum of 2 weeks from pitching.

It's true that after primary fermentation most yeast becomes dormant and fall to the bottom of the fermenter, but there's still millions of yeast cells dispersed in the wort. These yeast are most-definitely still active; they slowly chew through the remaining fermentables. This can be seen with the slow change in AG beers over time - they tend to slowly increase carbonation as the larger sugars (like maltotriose) are consumed.

I'm not saying it's the only way; I'm saying I'm a scientist and as such like to follow scientifically proven methods. It works for me. I also advise a little caution - just because a bit of extra time on the yeast cake is good, doesn't mean longer storage is more beneficial. If the wort is left on the cake for longer, say 1 month or more, then unwanted flavours will become obvious due to yeasts excreting fatty acids. Some will also die through autolysis and this results in shocking tastes and smells - think vegemite.

Sorry for the long post, but I though I should clarify my statement further.

Cheers n beers.


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## sosman (29/12/05)

junior06 said:


> i've heard its good to keep the beer in the fermenter for around a week or so before bottling, but because my fermenter isn't airtight will this cause oxidisation? should i bottle ASAP or will i still benefit from leaving it in the fermenter?
> [post="99775"][/post]​


That works for me although sometimes I am in a hurry and bung it in a keg in as little as a week after pitching. Bottling might require some more care. Good healthy yeast kick around for quite a while after "fermentation is finished".

I very rarely secondary, but I'm just lazy. Although my beers still come out ok. The clear ones are clear and the cloudy ones are cloudy.


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## Screwtop (29/12/05)

Great debate NRB tertiary study vs industrial training and experience. Although I doubt our repartee is of little benefit to the initial thread. The perfect opportunity for me to ask some questions and have some grey areas cleaned up for by own interest. So as not to waste bandwidth and hijack the thread you can PM me. 

I had believed that diacetyl was only produced by the ester Acetolactate when oxygen or high temp conditions where present, and that phase 4-6 cells re-absorbed this. Also that a Diacetyl rest only required about three days once fermentation had ceased. And that this was only required when fermentation temps were above yeast strain medians. I have done a number of diacetyl tests on my beers and never found a trace of butteryness so haven't bothered (ales only) with leaving on the yeast cake for d-scrubbing. Look forward to your comments.


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