There variations on a theme when it comes to collecting it,everything from a simple wooden sliver suspended over a vessel to a small section of clear tube into a bottle. Mine is more the latter, but more tan the latter too.
Ray Mears said in one of his programmes that he likes to consume some birch sap as a sort of ritual, I have tapped into that (sorry, fully intended pun!). I have future designs on trying to make some into wine, but for the moment I just like to draw alittle off for the family and I to have a drink. Let me take you through my design which is essentially a pimped up water bottle.
This is a 75cl water bottle with a sports cap that I have attached a small length of clear tubing to using an old disposable ball point barrel. I cut it in half and secured the two ends onto the length of tube (which is about six inches long). I use the bottom bit to insert into the birch tree because the slight taper is perfect for engaging in the hole.
I put a hot skewer through the hole in the bottle's sports top and then wedged the top part of of the pen barrel in it. I put the bottle near the tree and position the pen section to a natural position on the tree (to keep the pipe from bending). The upturned appendage is a neck section of water bottle which was from a previous version of this collecting kit before I left the bottle lid on.
Using a size 7 drill bit I make the hole and then insert to tapered pen lid end and leave it to it's own devices. The above shot shows the bottle and pipe full but seeing as it's a wedge fit into a sealed bottle it doesn't spill or go anywhere.
To seal the hole I use a small wooden peg and once I've sawn off the excess I put a small amount of petroleum jelly around it. as you can just about make out one full bottle, just enough for a taste of spring and handily the tube is removable so I can stick it in the fridge. It always comes out cool bit not cold whatever the weather. 'Cheers', or with the properties that are claimed of this liquid spring offering, perhaps saying 'Good health is more appropriate?