Tree sap/syrup in spring?

[Dark Art]

Just wondering if you guys do this kind of thing in Finland? It used to be quite a bit deal back in the days since its possible to collect spring sap from almost any fruit bearing tree, maple, walnut or even birch and boil it down to a thick, sweet syrup that has a very good shell life. Given the fact that sugar in general was quite pricey and very scares resource, methinks that springsap gathering would be something most of people wouldnt miss if it could be helped.

[Erkka]

In springtime birch sap has been consumed as such. Kind of a primitive Northern version of mineral water. But I don't know if it has been boiled down to syrup, at least I'm not aware of any such tradition in Finland.

[Homocommando]

Slavs drank birch sap too.
It is the first time I hear about making syrup from anything else than maple though.

[Dark Art]

Try it, its very very easy, just time and fuel consuming (takes a while and you need quite a bit of raw sap). The trick is to collect it at the right time - ideally, it must be below freezing at night and above freezing at daytime. There is no real harm to the tree, as long as you do it cleanly and once finished, close the spot with tar. As kids we've drank birch sap mostly as is, but I know for a fact that some folks did boil it down to a syrup-like state. Birch or cherry are not as aromatic as maple, but its still pretty sweet and quite tasty in a pie or even on its own.

[Plotinus]

I heard that you can make syrup from any kind of tree there is, but some trees you have to use an impractical amount of sap to create a tiny bit of syrup, so people don't.

[Dark Art]

I think none of the conifers would do, nor something like an oak or any other tree with high tannin content in its bark, but yeah, I think quite a few would be fine to some point. In regards to practicality I honestly have no idea. I think the whole thing is rather impractical - you literally need buckets of raw sap in order to get anywhere. Dont know the exact proportions, but I think it might be something like 30:1, or even 40:1. So yeah, its impractical, but still very tasty

[JP_Finn]

If your sap has 1% sugar content, you’ll need about 86litres to get 1litre of syrup.. if your sap would have 5% sugar you’d need about 17.2gallons of sap for a gallon of syrup.

Birch sap has about 1.1% sugar content. So you’re looking at 78.2 times the sap for your wanted syrup amount.

Often drank as a “rejuvenating drink”, not boiled down to syrup.

[Dark Art]

Interesting. Are you sure about those numbers? Like I said, I not an expert in this - never done it myself, only saw my neighbors do it. From what I recall, they used mostly birch and cherry sap since there was plenty of those trees around, but they tapped other trees in their garden like walnut and apple. 86:1 sounds extremely high ratio to be bothered with, so its either their syrup wasnt as sugary as the ones you can buy today in a store, or maybe other trees had much, much higher sugar content that birch (I kinda doubt that). Or maybe your numbers are off? In any case, its an interesting topic and I think that springsap was rather important, since the spring is usually the time when the stores are low and variety is rather bleak. So a source of fresh "mineral water" would've been quite welcome I think.

[Homocommando]

if your sap would have 5% sugar you’d need about 17.2gallons of sap for a gallon of syrup.

According to google maple syrup is about 2/3 sugar.
So if you have 13 gallons of sap, there is about 2/3 of gallons of sugar (13 × 0,05 = 0,65), which means one gallon of syrup can be made from 13 gallons of 5% sap.

If your sap has 1% sugar content, you’ll need about 86litres to get 1litre of syrup..

0,65 / 0,01 =  65
So you would need 65 litres to get 1 litre of syrup actually.
Unless you are just talking about denser syrup (or I have missed something, idk I am not sap scientist).

[JP_Finn]

66% sugar content is bare minimum to preserve the syrup. Below that, it’d ferment.

[JP_Finn]

In contrast, night frost / day thaw in spring can have maple sap’s sugar content above 8%.

[JP_Finn]

Looks like Canadian maple syrup is expected to be 66% sugar, cutting awfully close on the preservation threshold.
(But they’re world pros with the stuff.... although, if they’d rate their syrup at 86%, they’d likely lose millions of dollars every year for the product not there...)

[Dark Art]

Ugh.... If maple syrup would be any sweeter, it would no longer be food, but rather an industrial glue.. I get what you saying, but seriously, it almost too sweet as it is. But thats personal opinion, what matters more is the fact that if you'd bump sugar %, then (I think) it would start condensing and eventually transform the syrup into a moist lump.

[JP_Finn]

Any higher than 86% and you’ll start to get the sugar crystallize. I worded earlier post  tad poorly.
It’s funny that higher grades of maple syrup have lighter color (more light pass through) than poorer grades. Sweeter, less robust/earthy. Yet, personally I prefer the mid brown stuff, not the light yellow...
and I put not more than 1tsp of syrup per slice of bacon. Kids love syrup on pancakes, I like strawberry or raspberry jam instead.

[Matti-patti]

There's actually an article on birch sap on website of the National Museum: https://www.kansallismuseo.fi/fi/kuukauden-esineet/2008/mahlakourut-kalannista

Stated uses:

Drinking it straight
Allowing it to ferment into mild alcoholic brew (with 1.1% sugar this seems rather shaky option without reinforcing it)

Flavoring barley gruel
Flavoring small beer

It's also stated that it can be reduced into syrup, but it's not very definite if this is actual historical usage from the wording. The page relates a statement from the Kalevala composer (and botanist) Lönnrot for 60:1 ratio for birch syrup. If birch sap has 1.1% sugar in it then 60 kilograms would have 0.66 kg sugar so that sounds about right.