How to tell the difference between Red and White Oak lumber

[JohnM Martin]

When viewing weathered oak lumber, is there any way to reliably tell whether or not a board is red or white oak? I recently thought I was buying a pile of air dryed white oak, and it turns out I think it is a mixed bag. Here are a couple of boards side by side from the same pile.

redandwhite.jpgredwhite2.jpg

[John K Jordan]

When viewing weathered oak lumber, is there any way to reliably tell whether or not a board is red or white oak? I recently thought I was buying a pile of air dryed white oak, and it turns out I think it is a mixed bag. Here are a couple of boards side by side from the same pile.

redandwhite.jpgredwhite2.jpg

You cannot rely on the color. I've seen some red white oak and some non-red red oak. The ray lengths in the two classifications are different, perhaps more reliable.

But if you want to be sure: Look at the end grain of the heartwood (not the sap wood). Shave a tiny bit with a single-edge razor blade and look at it with a magnifying glass. All red oaks have open pores, like soda straws. All white oaks have filmy tyloses embedded in the pores, easily visible, look a little "sparkly" with good light. (The tyloses clog the pores and prevent liquid from freely moving, the reason white oak is better for outdoor furniture and whiskey barrels.)

This article is good: https://www.wood-database.com/wood-a...rom-white-oak/
It shows some other ways to distinguish but none are as good as looking at the end grain, IMO.

More. Click on the photos of the end grain for enlargement.
https://www.wood-database.com/red-oak/
https://www.wood-database.com/white-oak/

Also look at some of the pages on the other red and white oaks so you can see the variation. There is a good list of each in the article on distinguishing I linked to above.

For many photos check out the hobbithouseinc.com web site. This will give some idea of the wide variation in board surfaces.
This: http://www.hobbithouseinc.com/person...ak,%20misc.htm
And this: http://www.hobbithouseinc.com/person...k,%20white.htm
And this: http://www.hobbithouseinc.com/person...oak,%20red.htm

This page instructs how to prepare and examine end grain, section 7:
https://www.wood-database.com/wood-a...ication-guide/

JKJ

[JohnM Martin]

You cannot rely on the color. I've seen some red white oak and some non-red red oak. The ray lengths in the two classifications are different, perhaps more reliable.

But if you want to be sure: Look at the end grain of the heartwood (not the sap wood). Shave a tiny bit with a single-edge razor blade and look at it with a magnifying glass. All red oaks have open pores, like soda straws. All white oaks have filmy tyloses embedded in the pores, easily visible, look a little "sparkly" with good light. (The tyloses clog the pores and prevent liquid from freely moving, the reason white oak is better for outdoor furniture and whiskey barrels.)

This article is good: https://www.wood-database.com/wood-a...rom-white-oak/
It shows some other ways to distinguish but none are as good as looking at the end grain, IMO.

More. Click on the photos of the end grain for enlargement.
https://www.wood-database.com/red-oak/
https://www.wood-database.com/white-oak/

Also look at some of the pages on the other red and white oaks so you can see the variation. There is a good list of each in the article on distinguishing I linked to above.

For many photos check out the hobbithouseinc.com web site. This will give some idea of the wide variation in board surfaces.
This: http://www.hobbithouseinc.com/person...ak,%20misc.htm
And this: http://www.hobbithouseinc.com/person...k,%20white.htm
And this: http://www.hobbithouseinc.com/person...oak,%20red.htm

This page instructs how to prepare and examine end grain, section 7:
https://www.wood-database.com/wood-a...ication-guide/

JKJ

This is great, thanks so much.

[Scott T Smith]

When viewing weathered oak lumber, is there any way to reliably tell whether or not a board is red or white oak? I recently thought I was buying a pile of air dryed white oak, and it turns out I think it is a mixed bag. Here are a couple of boards side by side from the same pile.

redandwhite.jpgredwhite2.jpg

Excellent response from John K. Jordan above. I'll add to it just a bit.

Although in general terms most white oak is closed pored and most red oak is open pored, there is a notable exception, and that is chestnut white oak. Chestnut white oak is open pored and thus not used for wine or whiskey barrel's. It is my personal favorite species for quartersawing though.

There are typically three methods that we use to determine red versus white oak. The first is the pore test, as mentioned above. The second is to measure the rays in the lumber. Typically red oak rays are 3/4" or shorter, and white oak rays can extend well beyond 3/4" (but not ALL WO rays on the board - usually only a smaller percentage). See drawing below.


red vrs white oak end grain.jpg


The third test is to use a mix of 5% solution of sodium nitrite. A drop on one end of the board will turn a deep chocolate brown if the wood is white oak. Red oak will turn a lighter greenish / brown color after 15 minutes or so.

[Kyle Foster]

The third test is to use a mix of 5% solution of sodium nitrite. A drop on one end of the board will turn a deep chocolate brown if the wood is white oak. Red oak will turn a lighter greenish / brown color after 15 minutes or so.[/QUOTE]

Is this test a permanent thing or does the wood change back? I have some funky things that I want to try out and a greenish brown sounds like it would fit the bill

Kf

[Bob Glenn]

I've always been told, red oak is white and white oak is brown, however, light colored woods turn darker with age, dark color woods lighten with age, so who knows?

[Andrew Hughes]

White oak does have a very distinct smell to me. I know it’s not very scientific more of a gift. Somedays a curse

[Scott T Smith]

The third test is to use a mix of 5% solution of sodium nitrite. A drop on one end of the board will turn a deep chocolate brown if the wood is white oak. Red oak will turn a lighter greenish / brown color after 15 minutes or so.

Is this test a permanent thing or does the wood change back? I have some funky things that I want to try out and a greenish brown sounds like it would fit the bill

Kf[/QUOTE]

Kyle, it's permanent on the surface, but usually does not penetrate more than 1/16" or so. The exact shade of green/brown depends upon the species of red oak. Willow oak tends to turn more green than southern red oak.

[Pete Taran]

I prefer mass spectroscopy myself for the most definitive answer. Seriously though, white oak is much heavier and well, looks white. I've never had an issue telling the difference. Additionally, when planing red oak, it reminds me of the smell of applesauce.

[John K Jordan]

...white oak is much heavier and well, looks white. I've never had an issue telling the difference. ..

I cut some oak on my sawmill a few months ago, the guy said it was white oak. After cutting into it I recognized it as red oak which I'd cut a lot of. Turns out I was wrong, it WAS white oak, some type or another. Wasn't the least bit white.

I don't trust myself to judge from the color; there can on occasion be huge variation between specific species and individual trees.

But curious, can you even determine a wood species with a mass spectrometer? Seems like it will report a lot of carbon plus oxygen, hydrogen, calcium, iron, nitrogen, ...

JKJ

[Andrew Seemann]

When I see them in the lumberyard, red and white oak usually look quite different. Red oak typically has more of a reddish cast to the wood. and the white has more of a grayish brown cast, with the sapwood of both being lighter.

But............. when I see local trees that have been felled and cut into lumber, red and white (and maybe whatever other species of oak got milled) don't always look so different. For example, the old man had some red and whites milled up into lumber a few years back. After they weathered, I really couldn't tell them apart. Even planed they didn't look that different. Maybe growing in the same soil next to each other gave them similar color, who knows.

[Phil Mueller]

An interesting video on white oak vs red oak on YouTube:
”Wooden boat building - white oak vs red oak with Louis Sauzedde”

[glenn bradley]

Scott has you covered. Here's another view of end grain.

red vs white oak.JPG

[Lee Schierer]

Cut off a 1/2" thick piece from the end of a board and try to blow through it. If you can it is red oak.

[Tom M King]

To clarify things, in this country, every Oak (or at least as far as I know) is either a white oak, or a red oak. That doesn't mean that a white oak is White Oak, or a red oak is Red Oak.