Off flavors from Aluminum buckets?

[stimyg]

I’ve been making syrup for about 10 years, 30 taps, collecting in used aluminum buckets. Last year out of nowhere my syrup had a chemical or ~maybe~ metallic off flavor, strong. I’ve been working to isolate where it came from, especially since I’ve started to get a hint of it again this year. There are many areas the off flavors might come from. But this question is about the buckets.

Has anyone ever experienced anything like I’m describing, and traced it to aluminum buckets? I added a new batch of buckets last year so that is one (of many) possible sources.

It should be noted that I leave the sap in the buckets for a week or more. It’s a weekend home and that’s the best I can do. And sometimes we don’t get up every weekend. I know this can cause various problems and it’s not ideal. But I’ve done it for years without problem. But maybe it’s the new batch of (used) buckets. Or who knows.

Thoughts?

[Sugarmaker]

Might be the buckets? Could be metabolism from the trees? Could be from letting it set for a week in aluminum buckets and metabolism? Or none of the above. Not a good thing when you make off flavored syrup. Have a syrup expert near you to let them taste it? Could be buddy syrup? Do you have reds or hard maples?
Regards,
Chris

[stimyg]

Did a boil this past weekend, after 2 weeks hanging (some frozen, but some not)... and everything turned out fine! So I'm thinking it wasn't the buckets after all. Possibly a bad filter or two.

[Sugarmaker]

Good you had cool weather and some ice. Warm weather and that duration may have ended with spoiled sap. Glad the flavor was ok this time.
I wished we had a flavor meter for the industry!
Regards,
Chris

[DrTimPerkins]

I wished we had a flavor meter for the industry!

We do. It is called a "tongue" -- but it works way better when it has been calibrated (trained) properly. :lol: