In winter, wild food is thin on the ground, but inside birth trees the SAP is starting to rise. 

On the local supermarket shelf, next to the smoothies and coconut water, you may just spot a bottle of birch water. Long revered for its gentle sweetness and mineral-rich health benefits, birch water has now gone mainstream. Its popularity and increasing availability has been quenching a recent interest in healthier drinks and while stop-bought birch water is very tasty, nothing beats the fresh stuff gathered straight from the tree and full of nature’s nutrients. 

Birch water is basically sap, but not the sort of sticky sap that you see on a pine tree. It looks like water, tastes a little sweeter, and can be drunk as is, boiled down to make syrup or fermented to make vinegar, beer and very drinkable wine. It’s gathered from the common birch tree in very early spring and harvesting it is a surprisingly easy thing to do. 

Humans have worked sustainably with birch trees for thousands of years, relishing the sweetness of the sap when their winter larders grew stale and boring. The bark was used to make paper, baskets, even canoes; the twigs used for brooms and kitchen whisks, and the young leaves eastern fresh or dried for medicinal tinctures and teas. 

As a family, we love “tapping” into this foraging heritage, encouraging a little awe and respect for nature and getting out for a walk in the woods on a cold and blustery day. We’ve been collecting birch sap for the last few years in out local woods and it’s now become a bit of an annual tradition. A simple and exciting harbinger of spring. 

How to tap a tree

Tapping a birch tree requires some basic kit and a few ground rules. Unless you’re blessed with your own woodland, you should check with the local landowner before you tap a tree. To find out who owns the land, check with your local council or search HM Land Registry at

And before you head out you should know what sort of tree you’re looking for: native birch or beetles is common in the UK (you may even have one in your garden) and all varieties are suitable for tapping - take a good tree ID book if you’re not sure. I take ‘Trees’ by Alastair Fitter and David More as a pocket book on walks. The Woodland Trust ( also has good ID info. The tree should have a trunk that’s at least 30cm round (if our 12-year-old can get his hands around the trunk without touching finger tips, we’re good to go. 

Once you’ve chosen your tree or trees, there are many different ways to collect sap. Some people are a metal sprout or ‘spile’ with hook to hand a bucket, other use plastic tubing to drain the sap down into a bottle on the ground. The method that works best for us is a simple wooden sprout in the trunk, a plastic bottle and some string. Whichever way you choose, you will also need a hand-drill and wooden ‘bung’ (shop-bought or hand-crafted) to block the hole; sells tapping kits. 

It;s good to know the tapping for sap causes no harm to the tree and that the amount we collect is just a tiny fraction of its production. We collect no more than four litres per tree and only tap the same tree on alternate years. If you want lots of sap, use lots of trees rather than draining one. Most important of all is to stop the flow of sap once you’re finished. This will keep your tree in tiptop health. Other than that, collecting birch sap is a diddle, and a fun way to reconnect with our foraging past, while gathering something delicious fro the future. 

The best time to forage for birch sap depends on where you live, but a good yard stick is the time of year just before the birch leaf buds burst, usually very early spring, when you see frogspawn in the local pond. Once the sap is rising, you only have 2-3 weeks to collect, so you need to be ready. 


Using the penknife, make a hole in the topside of the plastic bottle (a cross works well). Now drill a small holes in the tree trunk, 21/2cm deep and 80-120cm from the ground, angling your drill slightly upwards. 


Push the wooden tap firmly into the hole. It need to be a snug fit. Position the bottle over the end of the tap and securely attach it to the tree with some string, making sure it won’t slip with the added weight of sap. 


Come back and check the bottle after 24 hours. You could collect around 4 litres (8 pints) in this time. A smaller amount could mean that you’re either too early or too late. Don’t be tempted to leave the bottle on for more than 48 hours, as the sap will start to ferment. 


Remove the tap and place the bung very firmly in the hole. You could also squeegee in sealed around the edges. Check for any leakage. 

Drink, eat and be merry.

Birch sap needs to be kept in a cool place and will only last 2-3 days. It’s great to drink just as it is or try making wine, syrup, vinegar or beer. If you’re short on time. simple freeze the sap in ice cubes trays - it’s delicious with whisky. 

Birch tree wine


  • 4 litres of birch sap (as fresh as possible)
  • 1kf sugar
  • 200g raisins 
  • juice of 2 lemons
  • 5g wine yeast (1 sachet)
  • 1 large bucket 
  • 2x4.5 litre demijohns with airlocks
  • sieve 
  • funnel 
  • 4 or 5 x 750 ml bottles


  1. Give everything a good scrub and sterilise with a hot soapy water. Put the sap in a large pan and bring to the boil. Add the sugar and simmer for around 10 mins until the sugar dissolves. Pour into the sterilised bucket and add the raisins and lemon juice. Leave to cool. 
  2. ‘Activate’ the yeast according to the packet instructions and sprinkle into the bucket. Cover loosely with a cloth and leave to ferment for around 3 days at room temperature. 
  3. Strain out the raising and decant into one of the memjohns. Seal with an airlock. Leave upright in a warm, darkish place for around 4 weeks. Sediment will collect at the bottom of the jar. 
  4. Decant the liquid into the second demijohn without disturbing the sediment and seal again with an airlock. Discard the sediment. Leave upright in a warm, darkish place until fermentation is complete (when no more air bubbles rise into the airlock). This could take another 4 weeks. 
  5. Decant the liquid into your sterilised wine bottles, again without disturbing the sediment and sea. Discard the sediment. 
  6. Store the bottles n their sides in a cool place (if you’re using corks, make sure they’re tight! and leave to ‘age’ for at least 3 months. Best after a year, if you can wait that long!