Every year, I have a few questions about the universal problem faced by all sugarmakers – fighting heavy niter build-up. With heavy flood runs, this can be increasingly problematic to battle.
Here is one question I received:
Does anybody have any advice on how to get this pasty mud-like stuff to filter better. I have been battling this for three years now and don’t know why, any advice would be greatly appreciated!
This was my answer to his question:
You have a problem that hundreds of producers have every year. So you are not alone in your question of how to deal with this problem.
Niter is caused by minerals precipitating out of the sap as it boils, and every woods if different in the amount produced. In fact, the amount of niter you battle in your sugarhouse is correlated with the mineral content of the soil in your sugarbush. When we boil sap, it is very similar to lime forming on a pan after you boil hard water several times.The only difference is that we are keeping the niter in solution and filtering it out. That is the key to removing niter. You must keep it in the solution until you run it through your filter, and you need to keep your syrup very hot and filter it immediately. If the filters cool for a long period of time, sugar will likely crystallize on the filter and slow flow. If you are using a felt or orlon filter, always use a pre-filter. In fact, try stacking several filters in layers and when the filter flow slows down, you can just pull off the top layer and continue to filter the syrup.
If you use a filter press, make sure you use enough filter aid to initially charge the filter. Even though filter presses have filter papers in between the metal plates, it is the filter aid that actually does the filtering. Make sure you use enough filter aid, but do not over do it. Mix the filter aid and the syrup completely before running the press. Keep the syrup hot and try to run larger batches. If you run small batches, the filter press cools and you will not be able to run as much syrup through until you change filters. Watch your pressure and change filters when the pressure starts to build excessively. This should prevent blowouts and having to re-filter.
Normally we filter with a conventional filter tank with a stack of 5 to 10 pre-filters on the tank and 1 orlon filter. I try to put enough pre-filters on for the better part of the day. After we filter, we transfer to a 20-gallon heating tank. Heat the the syrup to 185 and then run it through a pressure filter into 15 gallon drums. I try to never bring syrup back to boil or more niter will precipitate out.
Hope this helps and good sugaring.
Author: Les Ober, Geauga County OSU Extension 