A fortnight ago the sap moon rose and with it our first attempt at tapping.
Birch trees can be tapped in the same way that maple trees can. In maple-rich regions people collect the trees’ sap towards the end of winter – temperatures need to dip below freezing at night but rise above it during the day – and then boil it down over open fires to make maple syrup. Birch sap syrup tastes quite different, and takes a lot more boiling, but is now being talked up for both its complex taste as well as its health benefits. A litre will set you back about £130.
Making maple or birch syrup out of the sap has traditionally provided a source of sugar which can be stored for a year until the sap starts to run once more. It takes 100 litres of birch sap though to make 1 litre of syrup, compared with 40 for maple, so many cultures have preserved birch sap in different ways. In Russia and eastern Europe, simple fermentation seems to be the favoured method. There are also birch wines and birch beers. And many people simply drink the sap fresh.
This is what we’ve been doing with the sap collected from the two birch trees we tapped in our field. The sap is stuffed with all the right buzzwords, from vitamins and minerals to electrolytes and antioxidants, and can apparently act as a detoxifier. It tastes almost like water, and on the couple of hot sunny days we had recently proves a refreshing drink.
I did spend two hours simmering a panful of sap down to a mouthful of syrup. The syrup itself is sweet but with what foodies call an earthy flavour, and smelt almost mushroomy as we boiled it down. And, after trawling through some fairly dodgy Russian sites with lewd adverts and bad English, I finally got myself a recipe for birch sap kvass, as well as a phone virus. I tried fermenting a batch as instructed with a little bit of sugar and some raisins. This wasn’t a great success. After a few days of tasting like very sweet water, it started to taste like slightly off very sweet water. So I ditched it. I’m sure though with a bit of experimentation it would be possible to find the right recipe and method.
If we had more birch sap than we could consume fresh, I’d probably ferment rather than convert to syrup just because of the energy use involved – unless of course we were doing this on a large scale with lots of birch trees, a perpetual fire and someone on continuous simmering duty. I’m thinking commune large scale not commercial large scale, and anyway the few businesses who are producing birch syrup tend to favour using reverse osmosis over wood fires. Or perhaps even better would be to just remove the tap and stop robbing the tree of its life blood.
Because tree tapping is fairly controversial. There are many foragers who advise against it altogether and others who say it is better to collect from a branch rather than by drilling a hole in the trunk. There are concerns over whether a tree is able to recover from the tapping, especially if the hole becomes infected, and others who say it’s been practised traditionally for centuries and is harmless. And there is much conflicting advice over everything from what kind of a hole to drill to whether to plug the hole afterwards and if so how. As with all modern foraging, the problem is twofold: one, we are now too many and the trees are now too few; two, we no longer grow up with the practical local knowledge required to collect food from the wild in a non-destructive and sustainable way. I remember reading in Robin Wall Kimmerer’s Braiding Sweetgrass how traditional harvesting of sweetgrass was done in such a way that always ensured enough was left for the plant, the earth and next year’s harvest. In modern non-traditional societies, despite good intentions we would-be foragers often inadvertently damage or destroy a plant and, sometimes, an entire ecosystem.
Drilling a hole into a tree certainly doesn’t feel very gentle. Still, following the manifold and often conflicting instructions I found online we drilled a little way in and then used a stainless steel straw to act as channel for the sap to come out. Most people set up a much neater system with a proper tap plus pipe leading down to a covered container, but our low-tech set up worked well and we just strained out the bugs. The first tree we tapped slowed down within a few hours and then gave perhaps a cup a day for four or five days. The sap then dwindled to almost nothing and turned cloudy and stronger tasting before stopping altogether. The second tree, which was smaller, gave about two litres a day for several days, then also began to slow down but at a much slower rate and is still producing a small cup a day. I’ve read the sap can become bitter as well as cloudy as it comes to an end. We have stopped up the hole in the first tree with a broken off twig from the tree itself, more to prevent foreign material, and thus infection, entering than to stop the sap, which had by then almost dried up. The sap runs for just two to three weeks, as the warmer weather encourages the tree to release the nutrients it has stored in its roots over the winter. It stops when the leaf buds begin to swell and bloom, although oddly enough I see that the leaf buds of the first tree, where the sap stopped first, aren’t yet unfurling while the second tree has tiny green leaflets forming and yet still gives a little sap.
I did also try the branch method, sawing off a forking branch and then trying to collect the sap. The branch gushed sap for a good hour or so but it was more difficult to collect. And after an hour it dried up to a small uncollectable trickle of damp. If you just want to taste it, though, and don’t intend to harvest it for any period of time, this would be a much more tree-friendly method.
There are apparently many more trees, in addition to all of the birch and maple varieties, that can be tapped, including in this country walnut, linden, alder, sycamore, ironwood and elm. And in India, as Gautam reminded me while I was writing this post, tree tapping is even more exciting. Palm trees tapped (by those amazing coconut-tree climbers) early in the morning produce a nutritious ‘neera’ (literally ‘water’), but within an hour or two it rapidly ferments into the much more popular toddy. Best of all, the free booze flows for many months.
Jungli Food 