Filtering syrup can be a frustrating process, but Orlon will do a good job of removing unwanted sugar sand.
Finished maple syrup should be filtered to remove sugar sand — the grainy sediment that is created every time sap or syrup is boiled — and other particulates and impurities. Sugar sand is not harmful if it is consumed, but it gives syrup an unpleasant graininess.
The most commonly used material to filter maple syrup is Orlon, a dense, synthetic acrylic material with a wool-like feel.
Orlon removes small unwanted particles and is used with a paper prefilter that removes larger unwanted particles. Orlon and paper prefilters can be purchased from most maple syrup supply dealers. When using an Orlon sheet or bag, always remember that the gentler you are with the bag or sheet, the longer it will last and the better job it will do. Don’t twist or wring your Orlon while filtering or washing.
If the syrup drains through too quickly, it may mean that the fibers in your Orlon have broken down and it’s not catching the unwanted sediment. If this happens, it may be time to buy a new piece of Orlon.
Filtering syrup can be a frustrating process, but Orlon will do a good job of removing unwanted sugar sand.
For best results follow these guidelines:
Never wash your Orlon with soap. It will flavor your syrup. Instead, wash your Orlon only with hot water. You may turn the Orlon bag inside out to wash the inside, but be gentle.
Never twist or wring out your Orlon or unduly pull or stretch it. This will make the material rupture, and it will do a poor job of filtering.
Always make sure your syrup is hot — 180°F (82°C) or more — before filtering. Cold syrup will just sit in the filter and not strain through.
Slightly dampen the Orlon with hot water before using. This will help your unfiltered syrup drain through. Take care not to get the Orlon too wet, as this may thin down your syrup.
Be patient! Orlon will do a nice job, but it takes time and may need more than one pass.
One year you may have a hard time filtering your syrup and the next year it may go through more easily. This is because the amount of sugar sand — the sediment created when sap or syrup is boiled — varies greatly from year to year.
If after filtering you notice more sediment in your containers than you used to, it may be time to buy a new Orlon filter. Remember that Orlon is not perfect and will not always create crystal-clear syrup the way a filter press does. However, it works well for smaller producers.
Orlon will last a few years if taken care of properly. If rinsed carefully, the paper prefilters will last for a few batches. It is a good idea to have extra prefilters on hand.
A filter press is a device comprising a series of metal plates lined with filter papers and a pump that pushes the syrup through these plates. Any sediment in the syrup is left behind in the filter papers. Use a filter aid (diatomaceous earth) to help the press effectively remove sediment from the syrup. You will use less filter aid to move your syrup through the press at the beginning of the season than toward the end of the season — as the season goes on, you will make lower-quality syrup because of the bacterial growth in your tapholes and on your equipment.
There are different types and sizes of filter presses made by many manufacturers. The goal when using a filter press is to move the maximum amount of syrup through the pump according to the manufacturer’s specifications. Generally, a full-bank pump will clean 40 gallons of syrup at one time. A short bank will clean 15 gallons, and a hand pump will clean 10 gallons. Check with the manufacturer of your pump to determine its actual size, how much syrup it can clean at one time, and how it should be assembled. Each manufacturer will have specifications unique to its filter press.
A filter press does an excellent job of removing sugar sand from syrup, but it can be costly.
The pump on a filter press is motor driven, pneumatically driven, or manually driven. Motor-driven pumps are generally belt driven, and pneumatic-driven pumps use an air compressor. Manually driven pumps use a hand pump to push the syrup through the press plates. Hand-pump presses are less expensive than the other options, but they take more work.
Even a small producer can use a filter press. There are small, reasonably priced presses available that will work with as little as 5 gallons of syrup. Even the smallest filter presses do as good a job as the big filter presses, and they can make your syrup look as clear as if it were packaged professionally.
If the syrup is very cloudy, it isn’t clean. This may be due to a broken filter paper, incorrectly assembled plates, or an upside-down plate. You’ll have to take your press apart to find the problem, reassemble it properly, then try filtering it again, beginning with recirculation (step 3).
When you have finished filtering a batch of syrup, or your press is starting to build more than 6o psi of pressure (you can see this by watching the pressure gauge), it’s time to clean the press and change the filter papers.
Filtering syrup is often a lengthy and cumbersome process. Using a filter press can make the process easier. These tips should make running the press simpler — or at least less frustrating.
Once your syrup has been filtered, you will want to put it in containers so it can be stored. If bottled properly, unopened syrup will never spoil. Properly bottled syrup can be stored at room temperature until it is opened, but once opened, syrup must be refrigerated.
Heat your syrup to between 180 and 205°F (82 and 96°C) before putting it in glass or plastic bottles. This will create enough heat to sterilize the bottle and seal the cap. If your syrup boils, it will form more sugar sand, and you’ll have to refilter it. Check your syrup often with a thermometer.
You can ladle your syrup from your pan into a funnel to get your syrup into the container. Or you can purchase a bottling unit from a syrup supply dealer. A bottling unit typically consists of a propane burner, a 16-by-16-inch (or similar size) pan that has a valve toward the bottom and a screen that fits on the top of the pan. These units work well for filtering with Orlon.
To use a bottling unit, simply pour hot syrup into the pan through an Orlon that sits on top of the screen. Turn the burner on to keep your syrup at the proper bottling temperature. Place your container under the valve, and open the valve to fill the container.
If your syrup is hot (at least 180°F [82°C]), you do not need to pre-sterilize new containers or caps. Dipping plastic containers, plastic caps, or metal caps with plastic liners in boiling water will compromise their integrity, and they may fail when used.
If you are reusing glass containers, make sure they are clean. The best way to do this is to dip them in boiling water. Do not use soap; the residue left behind will flavor your syrup. You will also need to purchase new caps, as the old caps will likely not reseal. It is best not to reuse plastic containers because they are very difficult to clean. They may look clean, but plastic is porous and can hold bacteria that cannot be seen. Old plastic syrup containers should be recycled.
Sugar sand. If sugar sand settles to the bottom of the bottles after you have finished packaging, fear not. Sugar sands are the naturally occurring particulates in maple syrup. They are not harmful if ingested; they just make your syrup a little gritty. Most of the sugar sands will stay at the bottom, and you can pour the clear syrup off the top.
Crystals. If large rock candy–like crystals appear in the containers, that may mean your syrup is too thick. Syrup stabilizes in liquid form somewhere between 66 Brix (32 Baume) and 68 Brix (38 Baume). If it is too thick when it is packaged, sugars in the syrup will drop from the liquid and form crystals until the liquid gets to the right density. These crystals will not develop right away, as it takes time for the syrup to stabilize in the container. To dissolve the crystals, you can add a small amount of water, then heat your syrup. Or when the syrup is gone, eat the crystals as you would candy. Generally, lighter-colored syrup crystallizes at a lower sugar level than darker-colored syrup.
Storing thin syrup. If you choose not to finish your syrup to 66 Brix and intend to keep the thin syrup for yourself, you will need to refrigerate it because thin syrup will spoil. It is important to note that it is illegal to sell thin syrup labeled as pure maple syrup.
Storing finished syrup. Syrup that is cooked properly and finished at 66 to 67 Brix or 32 Baume can be stored, unopened, for years when properly bottled, but it probably won’t stick around that long! Once a bottle of syrup is opened, it should be stored in the refrigerator to prevent the growth of mold. Mold will appear as a powdery skim floating on the surface of the syrup. As with cheese, you can remove the mold and eat the rest of the syrup. If you’d prefer, you can boil the syrup to make sure any mold growth is eradicated, but this will create more sugar sand. Opened, finished syrup will stay good in the refrigerator indefinitely.
We have some antique syrup on display in our sugarhouse. Packaged between 1930 and 1950, the syrup in these containers has become darker in color with time. We have not opened the containers to taste the syrup, but there is no mold growth.
There are a variety of containers made specifically for packaging maple syrup, but you can store syrup in any well-sealed, clean container.
Years ago it was a popular practice to package syrup in unlined tin containers. The problem with storing syrup in tin is that if it remains in the tin for longer than 6 months, the syrup will take on a “tinny” taste. In recent years, researchers found that some of the materials in the tin containers leached into the syrup, causing the tins to be recalled.
The tins available for sale today are lined with a safe, food-friendly material to prevent this leaching. The newer tins should have a better shelf life than old-style tins, but even so, glass is still the best way to store syrup.