Filtering darker syrup

[flyzone13]

As it get later into the season and the syrup starts to turn darker, is just me or does it take longer to filter the darker syrup? The light syrup that I did on my first few batches went through the pre-filters and the orlon real quick and it takes a bit of time to get it through once it got to a darker amber. Any thoughts?

[Ghs57]

Much slower, and filter is much dirtier. Could be that the sap is now invert sugars, which darken faster, and possibly produce more niter. Or just that it's more noticeable when it's darker. The filter may also be slightly clogged from earlier use.

[Russell Lampron]

There's a lot more bacteria in late season sap and the dead bacteria in the syrup is what makes it hard to filter.

[ennismaple]

Everyone has this problem. Early in the season we can get 70+ gallons through the filter press without changing filters. The last few runs it's more like 10-15 gallons. Eventually the poor sugar, strong taste as PITA of filtering makes you say to heck with this we're done!

[MapleMark753]

We use the prefilters and the thick orlon filters too. With later dark syrup, or almost syrup really, we take it right off the boil from the evaporator, and just put it through one older prefilter. Then, finish on propane and filter normally with the prefilter in the orlon. Its still slower than say golden or amber, but much faster than if no prefiltering had been done. And, the hotter the better to a point, say 190 instead of 180-185.
good luck, Mark