How much sap?

[asknupp]

I've got a brand new 2x4 continuous flow that will be on a block arch. My question is how much sap should I expect to start with for a decent boil. I don't really know what Gph rates to expect with this set up.

[wnybassman]

I don't like to fire mine up until I have 40-50 gallons, although I have with just 30 before. When it is really cranking I get somewhere between 8 and 10 gph, but most times it is probably a little less than 8gph. I try to run it at a depth between 3/4" to 1"

[acerrubrum]

I have a 2x4 as well and get around 10 gph. It takes about 10 or more gallons to get the pan deep enough to start up, so I usually wait until I have at least 55 gallons of sap before a boil.

[asknupp]

Boiled down about 50 gal of sap and didn't draw off any syrup. I would have thought at least a quart. But I took remainder and finished in turkey fryer and ended up with a gallon and one quart of medium amber . Am I being to cautious and conservative by running a depth of 1.5-2" of sap? The reason I'm asking is because I feel I spent way to long on fryer today. Takes me back to last year doing it all on fryer. No offense to people using fryer.

[Big_Eddy]

Loose Rule of thumb - continuous flow evaporators take 2 days of boiling to sweeten before the first draw.

A 2x4 flat setup with natural draft should run 8-10gph. Add forced air and you can expect 10-15. All kinds of ways to tweak that and stretch it out a bit more, but those are reasonable numbers to plan around.

Assuming that you will sweeten the pans then leave the sweet in the pans from day to day, I did the math some time ago to determine exactly how much sap is needed to sweeten a pan and get the first draw off. See link below. Without running the formulas, my recollection is that you need to boil off ~ 200 gallons of sap for a 2x4 at 2" before you will start to draw off syrup. After that you will draw off about a quart an hour

If you plan to finish each batch off and empty out the pans daily, then the math is different. You calculate the minimum amount of liquid you want left in your pan at shut down, multiply by 40 and that's how much sap you need to have before you start. For a 2x4 boiled down to an end of day low of 1/2" (small fire at the end!!!!!!) you want 100-120 gals to be able to finish it all in your pan.

[asknupp]

Thanks big eddy. I had seen where people were talking about sweetening there pans but thought it was ritual to say that for a first boil of the year. I wish I wouldn't have rinsed the pan down now. But all being said ordered more taps from cdl so hopefully I'll have more to work with sap wise.

[hfitch]

When you sweeten the pans, how long can the "almost syrup" stay in the pans between boils without going bad? Last year I boiled down to almost syrup every time, put into mason jars, and froze it. Then when I had enough, I unthawed and finished off. This year I'd like to leave it in the plan between boils but am fearful of it spoiling and making all the hours of evaporator basically a waste :(

[Super Sapper]

If it is too cold to have the sap run it should be fine for several days. If it is warmer and you are worried you can lite a fire and get it up to boiling and let the fire go out every couple of days to kill anything starting to grow in it.

[hfitch]

Thanks a bunch!! Never dawned on me to just boil it a bit!