Too air tight ? Pressure question help

[TerryEspo]

I am trying a new idea this year.

Health spile into a water jug.

No rain or snow gets inside, no bugs, ice forms in bottom and keeps saps very cold, not a perfect system but ok. for my 40-50 taps this year.

My question is I think my hole in the cap is too air tight on some of the caps. The tube is very tight going through the hole. Leak proof almost.18566

I ask now, if that is too air tight and competing with the tree trying to push sap out ? I open some jugs and the "swoosh" sounds happens with some, built up air pressure...

I am thinking I need to drill a tiny second hole in each cap to allow venting.

Does the tree have enough pressure to overcome my pretty much air tight cap system ?

Any input is appreciated.

Thx in advance.

[Haynes Forest Products]

So by now you have read a few threads about us vacuum guys talking about how important vacuum is and the higher the vacuum the better the production. So more vacuum more production. Pressure has the opposite effect so your doing everything you can do to stop production. Speed in collecting is also a factor. Try slotting the top of the bottles and threads so there is a POOR seal.

[NhShaun]

This happened a lot on my 14 gallons barrels with new 3/16 lines feeding into them. The barrels would build so much pressure I could hardly remove the top. But after I open it and release the pressure i would find the barrels almost completely full of sap. I drilled another hole on the top and inserted a 4 inch piece of 3/16 with a snug fit. It released the pressure build up and kept the rain water or snow melting on the lid from entering the barrel. Weird thing is, with or without the vent I almost always had the same amount of sap in that barrel on good runs.
I also tap a few trees onto half gallon mason jars for drinking purposes. Several of the tops would blow right off from the pressure when they were about an inch from the top. But they still managed to fill that far with a serious amount of pressure built up inside the jar. From what i have experienced it still produces similar amounts of sap with the collection tank vented or not, but it just seems right that they should be vented anyway.

[maple flats]

Keep the hole tight but don't fully tighten the cap on the jug, at least that is how I did it when I had tubing going down into 5 gal jugs.