Calibrating Pan Thermometer and General Pan Questions

[bryankloos]

Hey All,

I'm guessing my thermometer is in need of a calibration, as the syrup I'd drawing off seems awfully heavy. I start drawing off when the dial hits 7, and if it overshoots to 8 during the draw I usually stop at 6 to average 7. Filtering has been slow, and looking back a day later at the syrup it looks super heavy.

1. How often do you calibrate your thermometers?
2. What do you use to thin heavy syrup, and where/when?
3. What refractometer do you recommend?
4. Does niter build up slow the GPH of evaporation?

I'm going to boil off the rest of my sweet and concentrate today and then drain the pan for some maintenance/cleaning before the next big runs.

Thanks All,

Bryan

[MajorWoodchuck]

I have a beer brewing friend that loans me his digital refractometer for the maple season each year. I make sure he is well supplied with syrup. This one gauge is all we need to almost instantly read sugar content from 0.1 to 85 brix. Two drops is all it takes. I usually take 2 -3 readings with it when I'm pulling off the evaporator and when finishing. So handy as I am running 6 hotel pans and I can get instant readings of where they all are at. Some people disagree on the accuracy of the meter but it has worked very well for me and my syrup has no sugar crystals in it or mold even after sitting on the shelf for 2 years. If my friend didn't borrow me his I would definitely buy my own for $200 as I think it ranks just under a RO for making the process enjoyable.

[Openwater]

Dan,
What brand/model is your brewer friend's dig refractometer? I've been looking for a reliable one that I can use for both sap and syrup.

[Father & Son]

As far as thermometers go good luck, I only use them to get close to syrup. For syrup finishing the hydrometer is the go to for most sugar makers. Refractometers wether it be prism or the more expensive digital can also be an every day tool. For most the digital refractometers are price prohibitive but the advantages are enormous. The more affordable is the prism refractometer. They can be found on eBay or Amazon for sometimes under $25. I have three prism refractometers, a 0-10 brix for sap, a 0-20 brix for concentrate from the RO, and a 0-85 brix for syrup. If purchasing one it needs to say “ATC” which is automatic temperature compensating meaning it can be used in cold conditions or warm. The reason all the ones I have chosen have a scale starting at “0” is so they can be calibrated with water. The others with ranges like a 45-85 brix you have to buy special calibrating fluid. If digital is for you, the one I have wanted for a long time is the Misco eMaple. Hope this helps.

[MajorWoodchuck]

Dan,
What brand/model is your brewer friend's dig refractometer? I've been looking for a reliable one that I can use for both sap and syrup.

It is the Hana brand that sells for about $200.
22972
I see a similar but cheaper unit on Amazon for 150 that has some good maple reviews.
22973

[MajorWoodchuck]

For your question on how to thin too heavy syrup you could use your permeate from your RO. You shouldn't use raw sap because it will introduce bacteria to your finish syrup.

[Father & Son]

It is the Hana brand that sells for about $200.
22972
I see a similar but cheaper unit on Amazon for 150 that has some good maple reviews.
22973

Be careful with the temperature ranges. Hot syrup may damage or give inaccurate reading.
Both are rated 0-80 C (32-176 F)

[TapTapTap]

Theoretically, you're supposed to calibrate a thermometer prior to each use by checking the boiling point of pure water.

[MajorWoodchuck]

Be careful with the temperature ranges. Hot syrup may damage or give inaccurate reading.
Both are rated 0-80 C (32-176 F)

I really doubt that the syrup is above 176f by the time I suck it up with a eye dropper and put a couple drops on the sensor lense. I also always take 2-3 readings from the sample to make sure it is "stabilized". I am not worried on the hot syrup hurting the flint glass and the temperature the sample is at is displayed on the meter anyways. I will see what temp it reads for hot syrup next time I am boiling.

[ebliese]

1. I have calibrated my evaporator thermometer once. I use it as a rough idea when I am close to syrup but rely more on my hydrometer. When my hydrometer shows I am at syrup, I look at the thermometer and note what it is showing. I've had days where it's at 4, some at 6, some at 7, etc.

2. When I bring my syrup into the house (already been filtered from drawing off), I usually use sap. However, I boil the sap first to kill any bacteria. Then the sap gets filtered and mixed in with the syrup. As others have said, you could also use permeate.

3. I can't recommend a refractometer since I don't have any experience with one.

4. I am not sure about the niter build up slowing evaporation, but if niter builds up too much, it will create a layer between the pan and the syrup and burn. Which if the niter is absorbing some of the heat, I would think it could slow evaporation.