Sunday, April 10, 2016

Collecting Birch Sap for Syrup, Part 1

In 2013, I wrote a blog article about collecting birch sap in the spring to make beer.  Since that topic has continued to attract hundreds of readers, particularly this time of year, I thought an update might be in order, especially now that we have “amped up” collection to hundreds of gallons and now enjoy the delicious syrup, too.

Whereas collecting a few gallons of sap from a few trees is very cheap and easy to do, and nutritionally/flavorfully worthwhile for residents of a boreal forest, collecting enough and cooking it down to syrup is a huge endeavor, perhaps better suited to a business or affinity group. Below is our experience over several years.

The previous collection method
In  2013, we picked four trees close together, tapped them, and let the sap drip into a vinegar bottle we bungee corded beneath each tap and thus collected an initial 2.5 gallons. Because we were so pleased with the flavor, nutritional value, and versatility of the sap, the next two years, we “uppped” our take to 15 gallons, collected by a length of food grade tubing connecting each tap to a five gallon bucket at the foot of each tree.  We collected our target amount in only 3 or 4 days. Easy in, easy out.

Five gallons were immediately deployed as the liquid (replacing water) in a batch of home brewed spring beer.  (Bryan reports that he could not discern a difference in flavor or texture from the 2013 batch of 1/2 water and 1/2 sap, but he enjoys the contrast to his chimay recipe made with 100% water.)  It  has an initial taste of wood and banana.  The banana flavor recedes, but a pleasingly light woodiness and sweetness remain.

The rest of the sap I like using as a  replacement for water in coffee, tea, oatmeal, pancakes, and even rice.  The sweetness is subtle – only about 1% - but birch sap contains vitamin C, iron, riboflavin, zinc, manganese, calcium, thiamine, magnesium, and potassium. What a wonderfully healthy spring tonic!     

Installing sap drainage lines, 2016
Last year, my husband decided to ramp up our sap collection to make syrup.  His idea was that the birch trees on our property are a free resource and that the syrup could supplement our fall honey harvest as another home grown, organic, shelf stable sweetener.  Because of the low natural sweetness, reducing the liquid from sap to syrup requires a huge volume and a major time commitment:  about 100 gallons of sap and 16 hours to cook down to one gallon of syrup!!!!  (By contrast, maple sap, I have read, reduces from 40 gallons to 1 of syrup).  And for us, living remotely, it took many months of planning, purchasing, and hauling the supplies to get to that first gallon.

The rest of this article describes assembling the collection apparatus in the woods.  The following article (Part 2) describes the syrup reduction process.

Obviously people have made syrup “the old fashioned way” for generations, but Bryan decided to buy “state of  the art” equipment from Leader Evaporator in Vermont, which has been selling to the maple and birch syrup industry since 1888.  This was not cheap, so frankly, for a family of two, with no commercial aspirations, I wonder if we will find it worthwhile.  In fact, I can put a cost of about $2,000 on our first gallon! We bought and shipped to Alaska 500 feet of 12 gauge wire, 500 feet of food grade tubing in thicker (3/4 inch) and thinner (5/8 inch) diameters (respectively, for the main line and the lateral lines to each tree), plastic and metal connectors and tools, taps, buckets, a 55 gallon food grade drum as a collecting unit, an assemble-it-yourself wood stove with 600 lbs of heat bricks, and the special, maze like cooking surface with spigots above and below, to pour the sap in and the syrup out. All of the paraphernalia, weighing 750 pounds, my husband ordered last year, transported by truck and stored at a lodge on the road system, and then hauled across country over several trips with his snow machine (snowmobile) sled.  

In February, 2016, we eyeballed our birches.   To collect 100 or more gallons of sap, we selected 25 thick trees more or less in a line along a hill and measured the distance between the farthest two.  This was about 230 feet.  We know from experience that a few trees will be big producers and others will not.  I hoped that we could keep notes on each tree, but I have found it difficult to discern drips from condensation in the blue, translucent lines. 

To take advantage of gravity, the sap collection point is at the lowest point of the hill, where Bryan built a deck last year (from a spruce he felled) for the purpose of supporting the woodstove and 55 gallon collection tank.

55 gallon collection tank
To assemble the collection line, we first had to create a surface along which we could walk among the trees.  So we pulled on our snowshoes and stomped out a pathetic path  The snow was powdery soft, so it was exhausting work, made worse by the fact that some parts of our intended path overlay a springy mass of alders bowed underneath.  Every once in a while, a hidden bough would grab the toe of a snow shoe and pitch us forward.  The path crusted over in the cold, and then we trampled it again and then again, until we manhandled a walkable surface hard enough for winter boots without the cumbersome 28 inch long snow shoes.  (Advice  to others: pick trees located where you can groom  a path with a snowmachine (snow mobile).   

When we opened the supplies from “Leader Evaporator”, they seemed to be of good quality, but the  process of assembly was NOT intuitive to a newbie.  Yet the company offers no “You Tube” video or “How To” FAQs on their website!  (Perhaps they rely on repeat business from commercial customers, not residential neophytes like us!)   Every day or so, my husband took a photo of the most recent thing he had done, sent it to the Customer Care department and became very familiar with a helpful advisor named Kevin, who patiently answered every question, usually starting out with something like, “Ah, Bryan, you assembled it upside down or backwards or used the wrong item for the task at hand.”  I hope that this experience helps them put together some FAQs for any residential customers they may ever attract.  Certainly our “not” photos will be useful.
Tapped birch trees

By mid-March, we had strung the 12 gauge wire among the trees.  Where there was a long gap, we shoved a staff of rebar into the snow as an intermediate support.  Below this dangled blue, food grade tubing.  Hanging that  took two people - one to wrestle  3 or so feet out of a tight coil that “wanted” to ping out of control, and the other person to attach the tube  to the wire with slim wire twist-ties every 18 inches or so.  Thinner blue tubing was attached to taps that Bryan inserted tightly into the birch trees with the help of a very fine drill bit.  From a distance, it looked a bit like something the artist, Cristo, would assemble in a woods and title, “Centipede.” Up close, it had a creepier hospital look of IV lines attached to two dozen trees.

We learned that setting up this system is very time consuming.  I doubt Bryan will want to take it down and redo it each year.  So I hope that summer foliage will obscure the blue line, which is a rather jarring note in our bucolic setting.  Once the snow recedes, we will be able to see if we hung it high enough that a moose won't rip through it.

Cementing the evaporator's fire bricks
If someone wanted to collect sap and not make syrup, this could be the end of the project.

But since we wanted to make syrup, Bryan turned his attention to assembling the outdoor woodstove to heat the liquid and reduce it down.  (See part 2 for information about that).

In prior years, the sap here had started running between April 20 and May 15  (the trigger is ground temperature).  But because this winter has been exceptionally (historically) mild,  we laid our bets that the sap would start flowing  between April 7 – 10.  Imagine our astonishment to see the collection tank slowly starting to fill, drop by drop, on April 2 – almost three weeks earlier than usual!  

Conclusion to this section:   It is so cheap and easy to collect sap from a few disparate trees, that I encourage  people who live in a boreal forest or having a birch tree in their yard to give it a try.  (Buy the taps, tubes, and food grade buckets from a vendor like Alaska Mill and Feed). Just plan refrigerated or freezer storage space within about 3 days.  The extensive and expensive “centipede/IV” system I described above is only needed for those who want to reduce vast quantities of liquid to syrup.

We enjoy collecting sap as our first sign of spring, before anything buds out.  Birch trees have many other benefits, for medicine, food, furniture, and beauty.  I am delighted to be surrounded by them. 


  1. Well done to you both, it will be worthwhile in the end once the sting of the cost subsides. That's for a fascinating article.

  2. Wonderful blog & good post.Its really helpful for me, awaiting for more new post. Keep Blogging! SAP in food industry. It was very informative.