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Some years ago I toured a maple syrup operation that has the opposite goal: Concentrate the dissolved stuff in the water. Their first stage was reverse osmosi

Some years ago I toured a maple syrup operation that has the opposite goal: Concentrate the dissolved stuff in the water. Their first stage was reverse osmosis, but only to a point. Second stage is boil, but with aggressive heat recovery from the steam to preheat the incoming liquid. All this to keep the energy cost under control.

jeffbee 3y ago
In an operation like that, do they heat the syrup under low pressure to reduce the boiling point of water?
- philote 3y ago
  I'd guess that if anything they'd increase the pressure to raise the boiling point. That way things dissolve in it faster and the water doesn't evaporate away.
  - tylerag 3y ago
    They're concentrating maple syrup. It comes out of the tree with the sugar and flavors already dissolved in it.
    - giantrobot 3y ago
      Part of the flavor of maple syrup is due to caramelization and the Maillard reaction of components of the sap. Just concentrating the sap would get you a syrupy substance sourced from a maple tree but it wouldn't be maple syrup.
      - MarkusWandel 3y ago
        I've never liked the flavour of maple syrup very much. At the same maple syrup place visit, we had some, on pancakes. WTF? This is plain table sugar! What kind of stunt are you pulling here? The guy supervising the boil said don't you know? The very best grade is like that, hardly maple-y at all! Turns out it really was about the sugar all along, with the initially undesirable maple flavour coming to be prized over time as a side effect.
        JshWright 3y ago
        The stronger colors and flavors occur later in the season. The warmer weather allows more bacteria growth in the sap, which metabolizes some of the sugar into other compounds.
        seanc 3y ago
        Fun fact, early abolitionists marketed maple sugar as a replacement for cane sugar, since cane sugar was made by slaves while maple sugar was made by northern farmers. So the old grading system rated the lighter colored plainer sugars and syrups higher than the darker more flavourful varieties. Since less maple flavour made for a better all-purpose sweetener and a more direct competitor to cane sugar. Nowadays we usually use maple syrup for the flavour, so the grading system is non-judgemental that way. And the darker grades are more likely what you want. https://www.vice.com/en/article/qvnyvv/maple-syrup-politics https://www.vice.com/en/article/qvnyvv/maple-syrup-politics
  - blamazon 3y ago
    On this topic the 14 minute episode "How Do They Make Maple Syrup?" from the PBS chemistry show 'Reactions' may be of interest: https://youtu.be/nSRCDiKMEJc https://youtu.be/nSRCDiKMEJc
    - kevin_thibedeau 3y ago
      I'll add Adam Ragusea's Hickory syrup experiment: https://www.youtube.com/watch?v=rT9IJXuHbKs https://www.youtube.com/watch?v=rT9IJXuHbKs
  - JshWright 3y ago
    The goal is to evaporate the water away. For every liter of finished syrup, you need to get rid of approximately 40 liters of water.
jtriangle 3y ago
That's more or less the correct way to run anything energy intensive, scavenge as much of the waste heat as you reasonably can. Theoretically, continuous distillation can be extremely efficient, as, you're removing as much heat as you're putting into the system. In reality, you get into diminishing returns fairly quickly, because insulation, pumps, heat exchangers, etc, are all far from free, especially at scale.
- hinkley 3y ago
  Counterflow heat exchange, baby.
ftxbro 3y ago
Does this mean I can buy watery maple syrup that is 2x watery for less than half the normal cost like maybe a quarter of the cost? Or does the volume and weight for shipping and handling offset that savings or does no one want watery syrup so there is no market so they don't make it?
- johnwalkr 3y ago
  Not Canadian maple syrup, it's regulated. I am pretty sure the regulations started from the producers getting together, or at least has the full support of the producers to keep up quality/reputation.
  - throw0101a 3y ago
    > Not Canadian maple syrup, it's regulated. Correct for things with that specific label, but other X syrup labels can be fair game: > In the United States, table syrups can be sold under a name consisting of any word followed by the word syrup with the exception of maple, cane, and sorghum. Commonly used names are table syrup, pancake syrup, waffle syrup, and pancake and waffle syrup.[1] * https://en.wikipedia.org/wiki/Table_syrup https://en.wikipedia.org/wiki/Table_syrup * https://en.wikipedia.org/wiki/Maple_syrup https://en.wikipedia.org/wiki/Maple_syrup
    - ftxbro 3y ago
      I assume that any syrup without a listed maple syrup grade is corn syrup.
- luhn 3y ago
  I think you're overestimating how much you could save. Rule of thumb is that it takes 40 units of sap to make one unit of syrup. (But this can vary widely depending on the sugar content of the sap.) So making syrup at half the concentration would require removing 38 units of water, instead of 39. That's not going to make much of a dent in the processing costs.
  - 3y ago

jeffbee 3y ago

In an operation like that, do they heat the syrup under low pressure to reduce the boiling point of water?

philote 3y ago
I'd guess that if anything they'd increase the pressure to raise the boiling point. That way things dissolve in it faster and the water doesn't evaporate away.
- tylerag 3y ago
  They're concentrating maple syrup. It comes out of the tree with the sugar and flavors already dissolved in it.
  - giantrobot 3y ago
    Part of the flavor of maple syrup is due to caramelization and the Maillard reaction of components of the sap. Just concentrating the sap would get you a syrupy substance sourced from a maple tree but it wouldn't be maple syrup.
    - MarkusWandel 3y ago
      I've never liked the flavour of maple syrup very much. At the same maple syrup place visit, we had some, on pancakes. WTF? This is plain table sugar! What kind of stunt are you pulling here? The guy supervising the boil said don't you know? The very best grade is like that, hardly maple-y at all! Turns out it really was about the sugar all along, with the initially undesirable maple flavour coming to be prized over time as a side effect.
      - JshWright 3y ago
        The stronger colors and flavors occur later in the season. The warmer weather allows more bacteria growth in the sap, which metabolizes some of the sugar into other compounds.
      - seanc 3y ago
        Fun fact, early abolitionists marketed maple sugar as a replacement for cane sugar, since cane sugar was made by slaves while maple sugar was made by northern farmers. So the old grading system rated the lighter colored plainer sugars and syrups higher than the darker more flavourful varieties. Since less maple flavour made for a better all-purpose sweetener and a more direct competitor to cane sugar. Nowadays we usually use maple syrup for the flavour, so the grading system is non-judgemental that way. And the darker grades are more likely what you want. https://www.vice.com/en/article/qvnyvv/maple-syrup-politics https://www.vice.com/en/article/qvnyvv/maple-syrup-politics
- blamazon 3y ago
  On this topic the 14 minute episode "How Do They Make Maple Syrup?" from the PBS chemistry show 'Reactions' may be of interest: https://youtu.be/nSRCDiKMEJc https://youtu.be/nSRCDiKMEJc
  - kevin_thibedeau 3y ago
    I'll add Adam Ragusea's Hickory syrup experiment: https://www.youtube.com/watch?v=rT9IJXuHbKs https://www.youtube.com/watch?v=rT9IJXuHbKs
- JshWright 3y ago
  The goal is to evaporate the water away. For every liter of finished syrup, you need to get rid of approximately 40 liters of water.

jtriangle 3y ago

That's more or less the correct way to run anything energy intensive, scavenge as much of the waste heat as you reasonably can. Theoretically, continuous distillation can be extremely efficient, as, you're removing as much heat as you're putting into the system. In reality, you get into diminishing returns fairly quickly, because insulation, pumps, heat exchangers, etc, are all far from free, especially at scale.

hinkley 3y ago
Counterflow heat exchange, baby.

ftxbro 3y ago

Does this mean I can buy watery maple syrup that is 2x watery for less than half the normal cost like maybe a quarter of the cost? Or does the volume and weight for shipping and handling offset that savings or does no one want watery syrup so there is no market so they don't make it?

johnwalkr 3y ago
Not Canadian maple syrup, it's regulated. I am pretty sure the regulations started from the producers getting together, or at least has the full support of the producers to keep up quality/reputation.
- throw0101a 3y ago
  > Not Canadian maple syrup, it's regulated. Correct for things with that specific label, but other X syrup labels can be fair game: > In the United States, table syrups can be sold under a name consisting of any word followed by the word syrup with the exception of maple, cane, and sorghum. Commonly used names are table syrup, pancake syrup, waffle syrup, and pancake and waffle syrup.[1] * https://en.wikipedia.org/wiki/Table_syrup https://en.wikipedia.org/wiki/Table_syrup * https://en.wikipedia.org/wiki/Maple_syrup https://en.wikipedia.org/wiki/Maple_syrup
  - ftxbro 3y ago
    I assume that any syrup without a listed maple syrup grade is corn syrup.
luhn 3y ago
I think you're overestimating how much you could save. Rule of thumb is that it takes 40 units of sap to make one unit of syrup. (But this can vary widely depending on the sugar content of the sap.) So making syrup at half the concentration would require removing 38 units of water, instead of 39. That's not going to make much of a dent in the processing costs.
- 3y ago