Copper turned sap blue

[billschi]

I boiled 30 gallons of birch sap yesterday. I made a bubbler with copper. I shut down last night and let it cool down by itself. The low temps got to 31 degrees. I got up this morning to clean the pan and start over with a new batch and noticed all the sap had a blueish color to it. Obviously this came from the copper. I noticed people had copper pans so I didn't think it would be an issue.
Did I ruin this sap?

[billschi]

After talking to someone who knows a lot me than me, I decided to dump my sap that I spent the whole day cooking down.

[Haynes Forest Products]

Well would you drink it?? My understanding is Birch sap is more acidic than maple. Im thinking you have Copper nitrate mixed in with the sap. I see copper fitting that haven't been wiprd clean after soldering and you will over time gat a green/bluish mess grow around the fitting. That is from the flux and moisture forming crystals on the surface.

What did you clean the bubbler with after you soldered the fittings inside and out??

[billschi]

I cleaned it like I do with my pan, Soap and water and rinsed well. The thing is, the copper pipe itself was changing, like it was breaking down. Now I have to find some stainless steel tubing.

[Super Sapper]

The more acidic birch sap probably dissolved the copper more readily than maple sap and adding the air helped to oxidize the copper is solution.

[Haynes Forest Products]

I still wonder how people get the flus out of the inside of copper preheaters. When I took mine and decided to scrap it I wasn't really all that concerned about draining it. The crap that came out after sitting a season with sap in it would gag a maggot.

[maple flats]

After soldering did you flush the inside well with hot water? That green hue may be from flux not properly removed.

[dark mountain maple]

One way to avoid having to deal with flux when working with copper is to Tig weld it, I'd suggest using a silicone bronze filler wire or a copper alloy, or to use fusion weld the copper with the heat of the Tig torch. Or another option is to find some used stainless milk pipeline and have a welder or yourself make a pre heater from that.