Although young birch leaves can be eaten (best in a mix of greens for a springtime salad) and a simple tea can be made from the young twigs along with their buds, the most delicious part of the tree by far is the sap.
The sap tastes a little like a slightly sweet mineral water and it's the best cure for a hangover I have ever found. It can be drunk straight or simmered (but not boiled) until it has reduced to produce a sticky syrup which can be used to sweeten desserts. This can be done on campfire coals or in a slow cooker. Around 98% of the liquid needs to evaporate to make the syrup, or for a sweet birch drink reduce by around 60-70%.
The hardest part of tapping for sap is timing. Traditionally the best time to tap is when the snow begins to melt but with increasingly snow-free winters this isn't a reliable garage.
Depending on where you live, the sap can be ready as early as late February or as late as early April, but it normally coincides with when the first celandines or early daffodils are in flower.
When the sap is ready the buds on the tips of the branches start to steel, however this can be difficult to spot if you are not in regular contact with the trees to be sure, cut off a piece of branch and see if a tear-like trickle of sap oozes out.
There are many different ways to tap a birch, but it is best to do it on the side of the tree facing away from anyone who might interfere with the tap.
There are two main approaches to tapping a birch tree: traditional and low-impact. Both are included below.
