The realisation for us a few years ago that you could tap birch trees was a significant one. That warm excited feeling in your belly, that once more nature surprises. What if we could produce our own natural syrup here in Ireland that would rival the Canadians Maple? Then of course once you know about it you start hearing about it everywhere and people who have been doing it for years start popping out of the woodwork.
Of native Irish trees you can drink the sap of birch, larch and sycamore. We have only tried to tap birch thusfar but will most likely give sycamore a go next year.
Your window of opportunity to tap a birch tree is about three weeks at the beginning of spring (we tapped this year in late March). You want to catch the sap as it is rising to feed the leaves of the tree. Once you start to see buds you should stop tapping and bung up any holes you have made, to keep the tree nice and healthy. The tree will keep producing enough sap to feed its leaves, but this does not mean you can bleed her dry, you should only ever take a small amount from each tree (two or three days worth at most) and try not to use the same trees two years in a row. Every tree is different and will produce varying quantities and subtle flavour differences, some trees may be sweeter or earthier than others depending on their habitat.
There are a number of ways to tap a tree.
- The purist most un-intrusive way is to simply make a slit at a 45 degree incline with a knife – you need to go about an inch deep, so use a good bushcraft knife that won’t snap (learnt the hard way on that one!) Then find a nice hardwood twig and jam it into the slit. You will need to wiggle and play with it a bit until you get the right angle for the sap to run down the stick.
- The more modern approach involves a hand drill and some sort of tap, funnel or tubing. Drill a hole about an inch deep and insert your tap/tubing (make sure to measure your drill bit before hand to get the right size so that the tap is snugly inserted into the tree, otherwise you will see some leaking.
For either of these methods you then need to secure a bottle or bucket to the tree to collect the fresh sap. Leave it overnight and come back the next day to see what nature has provided.
We tried out both of these methods and found the tubing to be considerably more efficient. Some of the trees with the twig method had simply stopped dripping when we came back the next day with only a litre of yield. Maybe we hadnt found the sweet spot. But the tubing worked a treat with no leaking and when we had finished tapping it was easy to bung up the cleanly drilled hole with other pieces of wood.
The fresh sap is a deliciously subtle fresh water like liquid. It has great health properties with loads of vitamin C and other minerals such as manganese, potassium and calcium. Many people simply drink it fresh or use it to make wine or beer. It looks like water , has the same viscosity and tastes like water until a delicate faint sweetness and floral note comes through at the end. It reminds a lot of people of coconut water. Concentrated down into a syrup this sweetness becomes more pronounced but there is more complexity there. The smell while it is reducing is amazing, almost like fresh waffles. The finished syrup is quite unique, almost like maple but we all had different opinions on it – some saying floral, others thinking it remains in the coconut relm, others more earthy or even like fungi.
To make birch syrup, like maple syrup, all you are doing is reducing the sap down on a heat until you reach a syrup. The bad news is that the reduction ratio is around 100 / 1 ie. You need 100 litres of sap to get 1 litre of syrup. Maple has roughly a 40 / 1 reduction rate
The fresh sap is great but it does go off. You will need to refrigerate it straight away and you’ve probably got around five days before it starts to turn. The syrup will last for months in the fridge.
Birch sap straight from the tree contains approx 1-2% sugar, mainly fructose. Maple sap on the other hand contains between 4-8% sugar and is made up of mainly sucrose. Fructose is generally considered as having a higher concentration of sweetness than sucrose and can be absorbed by the intestines a lot easier and faster than sucrose. But it can also be burnt a lot easier. Fructose burns at a much lower temperature than sucrose so to keep all the subtle notes instead of resulting in just a deep molasses flavour, you need to reduce the liquid down very slowly. This can be quite taxing on your energy bill!! But if you have a wood burning stove at home, put it on top of the stove and leave it reduce away over the course of a few days from the natural latent heat.
Below is a prime example of two syrups that have been reduced at different speed, the one on the right we had a lot more patience with and you can see and taste the difference.
Tapping a birch tree makes you realise how precious its syrup is, and makes you think about maple syrup and how we have all become so accustomed to it being on our supermarket shelves. Just there. With its label.
If you do decide to give it a go remember you are working with nature, a much greater force than you or I so respect that at all times. The tree is producing that sap to feed its leaves, so do not starve it. Make sure to bung up the hole properly to prevent disease and any unnecessary leaking.
And enjoy your time amongst the trees.