Off flavor from felt filters.

[Mud Island Maple]

Help! For the second year in a row our first syrup has been spoiled by off flavors from the felt filters.
We use the flat felt filters and prefilters for our W. B. Mason filter/canner and last year we took special pains to clean and store the filters so we wouldn't have the same problem as the previous year. After sugaring was done we thoroughly washed the filters in plain hot water and dried them on the clothesline for several days then brought them into the house and let them dry some more. Then we put them in a clean paper grocery bag and loosely closed the top and stored them in an absolutely dry closet shelf in our upstairs bedroom.
We made our first syrup today (about 2 gallons of fancy) and when we tasted it our hearts sank-- it had a strong musty filter flavor. What are we doing wrong or do we have to buy new filters every year? Thanks for any suggestions.

[KenWP]

Why a paper bag for one thing. And did the filters dry fast or slow slow. They might have got musty well drying. That or from the paper bag.

[trackerguy]

Always sniff before use - any smell at all, toss them out, syrup is too valuable to risk spoiling by trying to save a bad filter.

[PerryW]

It sounds like you are doing everything right.

Are you sure it's the filters?

Sometime the first batch of syrup can have a woody flavor with a taste like damp newspapers, especially if the tubing was not rinsed properly.

[Mud Island Maple]

Just an update about our filter problems. The filters had absolutely no odors before we used them. We even had a neighbor smell them. We don't use tubing . We tasted the syrup before it was filtered and it was excellent. We even filtered some syrup into another container to rule out any possibility that our canner was the source of the odor but it still had the musty taste. Anyway we bought new filters from Lapierre in Swanton and last night we boiled again.
We put just a small amount of syrup through the filter ( prefilter used also) and when we tasted it we were surprised to notice some off flavor- like slight musty filter. My sister-in-law actually tried the syrup first and reluctantly told us of the off flavor. We had prewashed the filters in hot water in a clean sap gathering pail. Anyway, not knowing what else to do we decided to run some more syrup through them and now the syrup tastes fine.
Is it normal to have flavor issues with new filters? The filters we use are the flat felts and when we were shopping for new ones we looked at some orlon ones but decided to stick with the regular felt. Does anyone know of any advantages to the orlons? Thanks.

[KenWP]

I use the orlons and so far no bad taste but I boiled them like I was told to make sure they were clean from the factory.