Syrup Taste??

[212Maple]

Last night I boiled down about 200 gallons of sap and produced some very light, sweet syrup, but there is a slight off taste to it. Prior to this I had boiled down about 600 gallons of sap which didn't have any off taste to it. I have two possible variables and would appreciate any opinions. 1.) recent cold weather that restarted the trees, Tuesday and Wednesday were largest runs of the year. 2.) Could there be something with the R.O. machine as it was not used until the last two days.

Thanks in advance!

[bob's sugar house]

It's the R.O , needs to be cleaned,someone with one can tell you how, I don't use one.

[maple flats]

On the RO did you run an hour worth of good clean low or no chlorine potable water thru first? If not and then change the pre-filter, you contaminated the syrup.