A seasonal birch water supplier can provide year-round commercial supply by separating the harvest calendar from the production and delivery calendar.
Birch sap is collected during a short period in spring. Commercial supply throughout the rest of the year therefore depends on what happens before, during and immediately after that harvest: expected demand has to be assessed, sufficient raw material has to be planned, part of the collected sap can go into immediate production, and the remaining volume can be prepared for aseptic storage and later production runs.
For an importer or distributor, the important question is therefore not simply:
“Is birch sap harvested all year?”
It is not.
The more useful question is:
How does the supplier turn one seasonal harvest into a realistic twelve-month commercial supply plan?
Birch Sap Yield Can Vary Substantially from Tree to Tree
One of the first questions I receive after showing buyers how birch sap is collected is:
“How much can you actually collect? Is there enough for regular commercial supply?”
It is a logical question. The collection period is short, and someone seeing the process for the first time may naturally wonder how a seasonal raw material can support repeated international orders throughout the year.
The starting point is that birch sap yield is highly variable.
Published field research illustrates the scale of that variation.
A Finnish study by Miina and Kurttila analysed data from 225 birch trees in 74 stands during the 2019 and 2020 tapping seasons. Average seasonal yield was 53.4 litres per tree in 2019 and 37.3 litres per tree in 2020. Individual tree yields varied much more widely: from 1.6 to 246.5 litres in 2019 and from 0.6 to 200 litres in 2020. The average tapping periods were 25 and 30 days respectively. [1]
A separate 2025 study by Kopeć and colleagues monitored 27 silver birch trees over a 29-day collection period in three forest site types. Average seasonal yield per tree ranged from approximately 124.6 to 176.8 litres, depending on the studied site. Individual trees showed an even wider spread, from 22.7 to 360.6 litres during the study period. [2]
Taken together, the two studies reported mean seasonal yields ranging from approximately 37 to 177 litres per tree under their respective study conditions.
This should not be interpreted as a universal commercial yield range for every birch tree.
The individual results were far more variable, and the studies were conducted under different conditions. They demonstrate precisely why commercial supply cannot be calculated by assigning one fixed number of litres to every tree.
Yield can vary with the individual tree, year, stand characteristics, collection period and environmental conditions. Miina and Kurttila also found that tree diameter and mean stand height were positively associated with yield, while the 2025 study showed substantial variation even between trees growing in the same site. [1][2]
For commercial supply, the harvest therefore has to be approached as a seasonal raw-material programme, with expected demand considered before collection begins.
For My Partners, Annual Supply Planning Starts in January
In my own work, I begin discussing the coming birch sap season with existing partners in January.
I ask for a realistic estimate of what they expect to purchase during the coming year.
The starting point should be actual sales from the previous year, adjusted for what the partner expects to happen in the current year.
If a distributor expects sales to increase, I need to understand approximately how much growth is planned. If sales are expected to decrease, that should also be reflected in the forecast.
I prefer these estimates to be expressed in real commercial quantities — for example, expected pallet volumes — rather than in general statements such as “we hope to sell more.”
Where several products or flavours are involved, the forecast becomes more useful when the expected volume is considered by SKU rather than only as one total annual figure.
The purpose is not to predict every individual order perfectly.
A forecast provides a realistic basis for deciding how much raw material and finished product may be required during the year. This is particularly important with a seasonal crop because the spring collection period cannot simply be reopened later when demand changes.
Seasonal Harvesting and Year-Round Production Are Two Different Things
Once the spring harvest begins, the collected birch sap enters the production system.
Part of the volume can be used for immediate production and bottling. Birch sap intended for later production is pasteurised before being transferred into aseptic storage tanks.
This allows raw material collected during the seasonal harvest to support production runs later in the year as commercial orders are scheduled.
The distinction is important:
The harvesting period is seasonal; production and commercial deliveries do not have to follow the same calendar.
Post-harvest handling also matters because fresh birch sap is a microbiologically sensitive raw material.
Sancho and colleagues followed birch sap throughout a complete tapping season and found that microbiota changed during the season and were associated with factors including collection timing and temperature. The researchers also found that freezing birch sap for two weeks reduced microbial counts but did not extend its subsequent shelf life. [3]
That research does not validate any particular supplier’s commercial preservation or aseptic-storage system. It demonstrates a more fundamental point for buyers: the way birch sap is handled after collection is an essential part of managing a seasonal raw material.
A serious discussion about year-round supply should therefore cover not only the harvest itself, but also the supplier’s processing, storage and later-production model.
A Pilot Order and a Larger Commercial Programme Require Different Planning
A new importer may initially want to test the product with a smaller pilot order.
If the pilot performs well and the partner decides to move into substantially larger volumes, I treat that as a new planning stage rather than simply multiplying the first order.
Before scaling, we normally clarify:
· expected annual volume;
· selected SKUs and flavour priorities;
· expected volume for each SKU;
· packaging format;
· production timing;
· approximate shipment timing;
· expected delivery timing.
Previous sales data and the partner’s current sales plan provide the most useful basis for these discussions.
The purpose is to understand what has to be produced, in what quantities and when it needs to be available.
A successful pilot can therefore develop into a larger programme without turning the next order into an emergency. Production, raw-material allocation and shipment timing can be recalculated before the volume increases.
Unexpected Growth Can Usually Be Managed, but It Can Change the Economics
Even a well-prepared forecast is still a forecast.
A product may sell faster than expected. A distributor may gain a new customer. A retail listing may increase demand beyond the original estimate.
In more than ten years of working with birch water, I have not had a case where such a development made an order impossible to fulfil.
I work with a primary production subcontractor that manages the full production process for my orders. If the available birch sap is insufficient for an additional requirement, I can approach other birch sap producers that I know within the industry and evaluate the possibility of sourcing additional raw material.
That does not mean purchasing raw material without verification.
Before using an additional source, I request the relevant laboratory test report, Certificate of Analysis (CoA) and product specification. The documentation is reviewed to determine whether the raw material and the supplier meet the requirements for the intended production before a purchasing decision is made.
Having access to another potential source can therefore provide additional flexibility, but it is not a substitute for supplier and product evaluation.
There is also a commercial consequence to consider.
Unplanned additional raw-material procurement can affect cost.
If additional birch sap has to be sourced outside the volumes originally planned for the season, the purchasing conditions may be different. This can affect the cost of the raw material and, consequently, the price of the finished product.
Advance forecasting is therefore not only about whether enough birch sap physically exists.
It also improves predictability around sourcing, production scheduling and cost.
What Should an Importer Ask About “Year-Round Availability”?
I would not judge a supplier’s year-round availability from one certificate or from the sentence “we can supply all year.”
I would ask the supplier to explain the operating model.
When is annual demand forecast?
Does the supplier discuss expected commercial volumes before the spring harvest?
How is the raw material handled after collection?
What happens to the volume that is not used for immediate production?
How are later production runs organised?
Can the supplier explain how orders placed months after the harvest are produced?
How is growth after a pilot handled?
Are annual volume, SKU mix, packaging and production timing reviewed again before scaling?
What happens when demand exceeds the forecast?
Does the supplier have access to additional raw material, and how are additional sources evaluated?
Could additional sourcing affect price or timing?
A supplier should be able to explain the commercial consequences of demand moving significantly beyond the original plan.
Clear answers to these questions tell an importer considerably more than a general promise of permanent availability.
Year-round supply is a planning capability, not a year-round harvest.
When Advance Annual Planning Matters Less
There are situations where a buyer does not need to begin with a detailed annual forecast.
If finished product is already available in stock and the requested quantity can be supplied from existing inventory, an order may be prepared for shipment without waiting for another harvest cycle.
That has happened in my own work.
Advance planning becomes much more important when the relationship moves toward repeated orders, larger volumes or a significant scale-up after a pilot.
At that stage, actual sales data and realistic expectations for the coming year give both sides a better basis for allocating raw material and planning production than treating every new order as an isolated event.
The Practical Meaning of Year-Round Birch Water Supply
For importers and distributors, “year-round availability” should be understood as a managed commercial supply system.
The raw material remains seasonal.
The commercial programme does not have to be.
A practical planning sequence is:
previous-year sales → current-year forecast → spring harvest planning → immediate production + pasteurised aseptic reserve → scheduled production runs → shipment and delivery planning
If demand develops faster than expected, the programme can be recalculated. Additional raw material can be evaluated and sourced where appropriate, while any effect on production timing or cost is considered before the next commercial commitment is made.
For buyers, that is the important distinction when evaluating the year-round supply capability of a seasonal product such as birch water.
Research References
1. Miina, J., & Kurttila, M. (2022).
A model for the sap yield of birches tapped by citizen scientists.
Silva Fennica, 56(2), Article 10679.
Natural Resources Institute Finland (Luke).
DOI: 10.14214/sf.10679
Study scope used in this article: 225 birch trees in 74 stands in Finland, with data from the 2019 and 2020 tapping seasons.
2. Kopeć, S., Staniszewski, P., Tomusiak, R., Bilek, M., Zastocki, D., & Moskalik, T. (2025).
The Relationship Between Biometric Features of Trees and the Intensity of Birch Sap Leakage in Various Forest Sites.
Applied Sciences, 15(9), 5024.
DOI: 10.3390/app15095024
Study scope used in this article: 27 silver birch trees monitored over a 29-day collection period in three forest site types.
3. Sancho, A. I., Birk, T., Gregersen, J. M., Rønne, T., Hornslet, S. E., Madsen, A. M., & Bøgh, K. L. (2022).
Microbial safety and protein composition of birch sap.
Journal of Food Composition and Analysis, 107, Article 104347.
DOI: 10.1016/j.jfca.2021.104347
About the Author
Natalia Schindler is the founder of Belorganic, an Austrian B2B beverage supplier and export partner based in Vienna, and the founder of Absolutely Wild®, its organic birch water brand.
She has worked with birch water for more than ten years, including product development, production and supply planning, private-label projects and international distribution.