Positive seal fermentation lock for wine barrels

A positive seal fermentation lock apparatus for a barrel having a bung hole, said bung hole having an inner circumferential surface, said apparatus comprising:

• a generally frusto-conical stopper member having a top surface, a bottom surface, and an outer circumferential surface for sealing against the inner circumferential surface of said barrel's bung hole, said stopper member including a central aperture having a length and a diameters;
• and
• a sealing insert member having a top portion, a middle portion, and a bottom portion, said top portion having a diameter greater than said stopper member central aperture diameter, said top portion having a lower surface for sealing against said stopper member top surface, said middle portion having a length generally equal to said stopper member central aperture length, and a diameter less than said stopper member central aperture diameter, said bottom portion including two flexible lateral projection elements to contact and apply a force against said stopper member bottom surface, so as to urge said top portion lower surface into sealing engagement with said stopper member top surface, wherein when gases form inside the barrel, the resultant pressure will exert a force against said insert member top portion lower sealing surface, and flex said lateral projection elements, breaking the seal formed between said insert member top portion lower sealing surface and said stopper member top surface, allowing the gases to escape.