How often to reverse flow?

[stimyg]

First day running my brand new 2x4 smokylake evaporator with a divided pan. Fun. Roughly how often do I need to reverse the flow to keep the sugar sand at bay?

I boiled for about 3 hours today and when it cooled I could see some free floating sand collecting, suspended, but nothing at all on the pan. Offhand I'd guess I could get away with boiling a full day or two before reversing, if not more. But I really have no idea.

Any rules of thumb here?

[RileySugarbush]

Tap the bottom of your syrup pan with a scoop or spoon, something metallic. If it sounds like metal on metal, no sugars and. When it sounds dull, you have a coating and should think about reversing. Very low sugars and here this year, almost none.

[JoeJ]

Reversing the flow will depend on how quickly and how much sugar sand accumulates. I draw off on one side of my pan and depending on the amount of sugar sand, I will have to clean after every boil or maybe every second boil. This year I cleaned the pan after 4 boils even though there did not seem to be much sand. That was a waste of time. After taking the sweet out of the syrup pan, the pan was completely clean. Then, after Friday's boil, there was some sugar sand in the draw off channel. I will have to clean the pan when today,s boiling is done. This is the first year in 17 seasons that I have had such a low amount of sugar sand (so far)

Joe

[stimyg]

Here's another question: what exactly is a problematic buildup of sugar sand? You're not talking about the free floating sand that you filter out when drawing off, right? It's when sand builds up on the pan itself?

Because after ~100 gallons of boiling I have a lot of the free floating sand, but I don't see any buildup on the pan itself. In which I case I figure it's not time to reverse yet...?

[maple flats]

I only reverse flow when indicated. As I get ready to start up again the next day, I use a nylon spatula and holding it at about 45 degrees to the bottom, I pull it towards me, if there is no resistance I fire up, if there is drag in the draw off channel and maybe the next one (I have 4 channels) I reverse the flow, if there is drag in 3 or 4 channels I clean the pan, v
When boiling if I see the boil changing much during a boil, I wait about 15 minutes without adding any wood to the fire then I draw the spatula across as stated above. Again drag in up to 2, I reverse flow, drag in 3 or all 4 I shut down and clean.
So far I've boiled 5 days for a total of about 1600 gal boiled and have not yet had any drag using the spatula method. Some years it is needed after 6-8 hrs of boiling sometimes half that. Each season is different and many locations will vary a lot.