How do you tell when your trees have budded?

[HowardR]

I'm trying to decide whether or not to pull my taps. We've had a warm spell and I'm doing my best to read the maple buds because once the trees have budded, the syrup will have a bad taste.

I found a Maple Bud Field Guide (https://www.uvm.edu/~entlab/Publications/MapleBudFieldGuide.pdf) (pdf) online on the University of Vermont website. It includes the following photos of leaf buds. If you go out to examine your trees, take binoculars as you may need them. You should choose a healthy dominant tree or a co-dominant tree. The following are the relevant photos of leaf buds from the field guide. (The flower buds are rarer and mostly in the upper canopy; they look a bit different after the dormant stage.):

The V0 bud is dormant

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The V1 bud has some initial bud swell. Bud scales are beginning to shift giving a reddish tinge to the bud.

http://www.pahomeschoolers.com/v1leaf.jpg
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The V2 bud shows some elongation making the top more pointed than round. A light yellowish color is visible between the bud scales.

http://www.pahomeschoolers.com/v2leaf.jpg
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The V3 bud has a green tip and the scales are light green. There is still no opening at the tip.

http://www.pahomeschoolers.com/v3leaf.jpg
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The V4 bud has bud break. Leaf tips are barely visible, expanding beyond the bud tip. The bud scales are loosened. I assume that at this point, the sap would have a "buddy" flavor and would no longer be good.

http://www.pahomeschoolers.com/v4leaf.jpg
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Am I correct that the V4 stage is the sign that it is time to pull the taps? If you have any advice along these lines, I would definitely appreciate reading it.

[psparr]

Just taste, smell, or boil the sap. It'll smell like dirty socks.

[DrTimPerkins]

Am I correct that the V4 stage is the sign that it is time to pull the taps? If you have any advice along these lines, I would definitely appreciate reading it.

Bud stage is really only a secondary concern. The main thing is the flavor of the syrup. If you detect buddy off-smell or flavor in the sap or syrup, it is time (or past time) to stop. Typically by the time buds reach the V4 stage the sap has been buddy for some time. We normally detect buddy at the V1-V2 stage and try to catch it before it affects the syrup flavor. That way we can process the sweet still left in the evaporator. If you go too long, you might as well dump the whole thing.

[O3C]

I have 200taps on 3\16 tubing running into a stainless bulk tank. On Tuesday morning, I went back to the woods to see what was happening and I had about 200 gallons in there but was very cloudy, so I took 5 gallon out and dumped the rest because I still had 300 gallon from Monday night to boil [ had some ice in it to keep it cool]. That 5 gallons we kept separate and boiled it down on a turkey fryer while we were running the 300 gallon through the evaporator. It didn't smell funny or taste funny until we let it sit overnight in the fridge. The next morning we tried it against the syrup from last week and it definitely had a bitter taste. So the questions I have for future years reference is there anyway to tell between if the sap got to warm on us [ it was 50-60 earlier in the week ], or weather it was buddy[ from the pictures above I would say the buds wre in the 1 or 2 stage ? If the bacteria is taking up sugar or the buds are using it up, is a refractometer reading lower than what it had been running going to help to determine when to quit ? Thanks, Ron

[DrTimPerkins]

So the questions I have for future years reference is there anyway to tell between if the sap got to warm on us [ it was 50-60 earlier in the week ], or weather it was buddy....[ from the pictures above I would say the buds wre in the 1 or 2 stage ? If the bacteria is taking up sugar or the buds are using it up, is a refractometer reading lower than what it had been running going to help to determine when to quit ? Thanks, Ron

Smell it....if it smells really bad, dump it.
Stir it....if it is ropey, dump it.
Taste it....if it tastes like crap, dump it.

If it still seems good, but you're still not sure, then boil a small amount on a stove. After it's been reduced by about half, smell it. If it smells like sweat sox, probably not good. Then taste it (let it cool first)....if it tastes bad, there's your answer.

Be aware that sap or sweet can pick up odors/tastes from other food in the fridge. Cover it to help cut down on that possibility.

[HowardR]

Bud stage is really only a secondary concern. The main thing is the flavor of the syrup. If you detect buddy off-smell or flavor in the sap or syrup, it is time (or past time) to stop. Typically by the time buds reach the V4 stage the sap has been buddy for some time. We normally detect buddy at the V1-V2 stage and try to catch it before it affects the syrup flavor. That way we can process the sweet still left in the evaporator. If you go too long, you might as well dump the whole thing.

Dr. Perkins, thank you so much for your guidance! You are an expert at the very same university that published the maple bud field guide that I cited!

So, the main change happens between V1 and V2. During V1 the sugar maple buds have a reddish tinge while during V2 they have a light yellowish color. That color change might be one of the easiest things for untrained eyes like my own to see. But, as you pointed out, the best test is to boil up a small batch of sap to see if it has an off-flavor.

Incidentally, I tap about twice as many red maples as sugar maples. According to Tom Wilmot (http://northernwoodlands.org/articles/article/when-tapping-dont-disregard-red-maple/) (one of your fellow researchers at the University of Vermont) red maples bud earlier than sugar maples, but their earlier budding doesn't seem to negatively affect the syrup quality. He also explained that red maple syrup is usually darker than sugar maple syrup. Specifically, he wrote:


So what about red maple as a tree for sap collection? I spoke to several people whose sugarbushes consist of a large proportion of this species. Some described their syrup flavor as “more maple,” some as “more caramel;” all claimed that their customers were very happy with it. The differences in flavor seem to echo the vast differences also found among sugar maple syrups from different soils and regions. Haven King, who buys syrup from sugarmakers all over the Northeastern U.S. and Canada for Maple Grove Farms of Vermont, told me that some of the best-tasting syrup he buys comes from sugarbushes that are mostly red maple.

Sugarmakers had varying descriptions of the niter produced from boiling red maple sap, with the yearly range from white to black and from light to heavy – just as is typical with sugar maple. No one described problems with buddy sap; apparently most red maples shut down sap production as the buds begin to open, or the sap turns buddy at about the same time as that of sugar maple. Sugar content was typically lower, but only by a couple tenths of a degree brix. Some stands of red maple ran earlier than sugar maple stands, some did not. Syrup made from a predominance of red maple is often a bit darker than sugar maple syrup, but not dramatically so. Sugarmakers who collect with buckets describe some red maples with very shaggy bark as poor sap trees but said that other trees were often very high yielding. Trees growing in a swampy area often have large heartwood centers, necessitating shallow tapholes.

[DrTimPerkins]

...red maples bud earlier than sugar maples, but their earlier budding doesn't seem to negatively affect the syrup quality.

The first buds you see on red maple are flowers, not leaf buds. They seem to have less effect on syrup flavor than leaf buds.

[O3C]

Dr. Tim, thanks for the information. Farming has always been a combination of art and science. My son is 6th generation dairy farmer [166 years]. I am 1st generation maple guy [3 years]. Just trying to replace the art with as much science as we can get away with ! Ron

[HowardR]

Before I posted this question to start this thread, I thought that you could look at the buds and tell if the sap would still be good. My conclusion, based upon this thread, is that the only way you can tell is by smelling, tasting, examining, and/or by boiling up the sap.