"Yellow" hard maple

[Larry]

Last February I dropped and sawed a red maple in the morning and by afternoon had it on sticks with air on it under shelter.  Its all 8/4, mostly for turning Christmas ornaments.  As a result I got some of the whitest maple I've ever had.

At the same time I also saw some a very faint yellow tinge with just a little bit of green on the edge of a few boards.  Doesn't show up in the finished product but wondering what caused it? 

[KEC]

Can't answer your question, but Red Maple is considered soft maple. Hard maple is Sugar Maple and the wood is more yellow. Don't mean to nit-pick.

[SwampDonkey]

Fungus or bacteria growing for the green and UV reaction for the yellow maybe.

I find red maple to be quite white and sugar maple goes yellow.

[GeneWengert-WoodDoc]

A small clarification.  Hard maple includes both sugar maple and black maple.  Both are white colored wood.

The yellow surface color is caused by the movement of liquid water to the surface from just underneath the surface.  That water has a bit so sugar and starches I. It.  When this water evaporates, these starches and sugars are concentrated at the surface and left behind and, depending on the weather, may oxidize to a yellowish color.  Because liquid water movement in hard maple is difficult, this event is limited to the surface.

[rojen]

A small clarification.  Hard maple includes both sugar maple and black maple.  Both are white colored wood.

The yellow surface color is caused by the movement of liquid water to the surface from just underneath the surface.  That water has a bit so sugar and starches I. It.  When this water evaporates, these starches and sugars are concentrated at the surface and left behind and, depending on the weather, may oxidize to a yellowish color.  Because liquid water movement in hard maple is difficult, this event is limited to the surface.

I have some hard maple in a home made DH kiln that's turning a bit yellow.  You're saying this will plane out? 
The boards with the most fan coverage seem to be keeping their light color better.
Thanks for all your input on these forums

[petefrom bearswamp]

I agree with doc as he knows for sure.
I agree that the yellow will plane out, sticker stain not so much

[YellowHammer]

Most times the yellow color in hard maple will plane out to a white, unless the log was sitting too long, or the boards were getting too much heat.  If the boards were white when they were sawn, then generally, they will plane out fine.  If there is a doubt, I sometimes will pull one and run it through the planer.  For us, the depth of the discoloration is the issue, we only plane off 1/16" and thats not much.  If it goes deeper, then it slightly devalues our wood.  

This assumes the normal conventions of proper kiln drying are being followed.  I have been offered hard maple from others that were deeply discolored, and which couldn't reasonably be planed out. 

[Larry]

The yellow was just on the surface.  Gene explained it well, thanks.

I've found a demand for bright white maple, and almost rotten maple.  The stuff in between those extremes, not a lot of interest.

[GeneWengert-WoodDoc]

I hate to say "always" but the yellow will plane off, as it is only a 1/100" or a bit more most of the time.  On the other hand, if the logs were older, the discoloration can go deeper.