# Dry Airlocks?



## trufflehunter (Aug 4, 2010)

Can anyone help me ? I am living in Italy, and just about to make my first batch of wine this Autumn. I have bought 2 stainless steel tanks, but they have dry airlocks., the plastic bell shaped chamber has a loose glass marble covering the exit which presumably is shifted by the CO2 during fermentation. But no liquid trap. Is this OK, will it work, or do I have to worry about air getting back into the tank ? I would love to know if anyone has seen or used a similar airlock, and if they had any problems with it ?
Strangely there is also a 2nd marble higher in the chamber that is also loose, but I cant figure out how this is related, of course, there are no instructions with the kit !
Many thanks !


----------



## djrockinsteve (Aug 4, 2010)

I think as long as the marble seals the opening preventing the air from entering you would be fine. Could you switch out the dry airlock for ones that you may add liquid to?

Can you google for directions?


----------



## trufflehunter (Aug 4, 2010)

*dry airlock*

Thanks Steve, yes the marble sits loose in a depression., as the CO2 is released it pushes the marble clear, the marble will then drop back into the hole and make a seal. I have no idea about physics and chemistry, but I am wondering if this is as secure as a liquid lock, it seems a bit primitive by comparison ? I could try and replace with a liquid lock, but it is a screw thread over a large opening in the top of the stainless steel tank, so I dont know how Id find one the same size.


----------



## grapeman (Aug 4, 2010)

If they are made that way, and sold in Italy they are sure to be effective.


----------



## Green Mountains (Aug 4, 2010)

A quick Google found this http://www.finevinewines.com/SStanks.pdf

Page 2


----------



## djrockinsteve (Aug 4, 2010)

If you are in doubt put a balloon on the top.


----------



## trufflehunter (Aug 5, 2010)

*Dry airlocks*

Darren the link you posted is very useful, all seems to make sense altho I am still cant see how the 2-way vent valve, plastic with marbles in, prevents air from entering.


----------



## trufflehunter (Aug 5, 2010)

*airlocks or vent valve?*

is there a key difference between and an airlock and a vent valve, i think I am missing something fundamental here,. The valve I have for my SS tanks is in the photo attached, and I cant see how it keeps the air out, it is not sealed;

White Plastic Vents
Most common and inexpensive. 
•	Pressure vents at 0.05 psi 
•	Vaccum break at 0.05 psi 
•	Maximum gas flow rate is 57 GPM. 
•	White plastic
•	Two marbles make seal against the plastic. One marble for vent, the other marble for vacuum. 
•	Includes top, backing nut and gasket. Fits thru hole in lid, back nut secures it. 
The max gas flow is important when pumping out the tank. Be sure the flow rate matches or exceeds the pump speed.


----------



## Green Mountains (Aug 5, 2010)

I'd say the marble seats into a hole and gets pushed aside when gas needs to escape and then falls back into the hole. It must be a good seal as the instructions warn against dispensing wine fromt the fermentor without opening the top to avoid creating a vacuum that could damage the unit.

Tell us...what do you plan on making with these SS fermentors?


----------



## trufflehunter (Aug 5, 2010)

*Air vents*

Hi Darren, I am planning to make approx. 50 litres of white, the variety is Pecorino, and 50 litres of Cerasuolo, that is a pink made from Montepulciano. 

But I am still not convinced, as the marble doesnt create a complete seal.....I wish I could explain it better......there is an air chamber that goes up the valve and around the marble that the marble does not seal, have you ever seen a valve like the 1 in the picture ?


----------



## rodo (Aug 5, 2010)

Even an S-lock can let air in. This would not occur in the early stages of fermentation but as things slow down and through the aging process if there is a large temperture change air can be sucked in.


----------



## rodo (Aug 5, 2010)

I think the main purpose is to keep out things like fruit flies while being able to vent the Co2 being produced by the fermentation process.


----------



## angeljimenez (Feb 15, 2017)

The two marble "dry" design is to accommodate the volume of gasses released while fermenting larger volumes. An 'S' type airlock might blowout all its liquid if you attached it to, say, a 13 gallon tank.

I also felt that air might enter through this two marble design but the thing to keep in mind is that by the time fermentation finishes, the must is saturated with alcohol and not very hospitable to nasty microbes. During the fermentation, air pressure is positive within the fermenter thereby preventing the easy entrance of air. Furthermore, if you keep the floating lid directly on top of the must, you will probably generate foam which will fill up the reservoir surrounding the lowermost marble and act to more thoroughly seal the lowermost valve.


The purpose of the uppermost valve (marble) is to let air in in the event a vacuum is created as, for example, when removing wine from the stainless steel fermenter.


----------

