by Eric Meier
The typical smart-aleck response might be: “well, red oak is red, and white oak is white. . .”
Not so fast. There are all sorts of color variations seen in oak lumber, depending not only on the exact species of oak, but also from the growing conditions from tree to tree. From first glance, just going by color, (especially if the wood has a stain applied to it), it can be difficult to tell the two apart.
So, how do you tell the two apart, and why would you want to?
First I’ll cover a few quick ways to tell the two groups apart, and then I’ll describe the working properties and characteristics of each group. But before we start, let’s take a look at the two groups, and which oaks fall into which groups:
While there is one specific wood species (Quercus alba) that is commonly considered the “white oak,” and there is one specific species (Quercus rubra) that is considered the “red oak,” the truth of the matter is, when you buy oak lumber within North America, oftentimes you will not actually be buying these two exact species, but instead you may be buying one of the oaks contained within the two broad red and white groupings found in the table above. Basically, you’re buying characteristics found in an oak group, and not necessarily an exact species.
Now that we’ve got a general overview of the species involved, let’s take a look at different ways that will reliably enable you to tell the two groups of oak apart:
1. Look at the endgrain
A quick and fairly reliable way to tell the two oaks apart is simply by looking at the endgrain. In order for this to work, the ends of the board can’t be painted, sealed, or rough-sawn. A freshly cut oak board should be easy to distinguish:
The pores found in the growth rings on red oak are very open and porous, and should be easily identifiable. White oak, however, has its pores plugged with tyloses, which help make white oak suitable for water-tight vessels, and give it increased resistance to rot and decay. The presence of tyloses is perhaps the best and most reliable way to distinguish the two oaks, but it comes with a few caveats:
1.) Make sure that you’ve cleaned up the endgrain enough to see the pores clearly, and blown out any dust from the pores. You don’t want a “false-positive” and mistake sawdust clogged in the pores for tyloses.
2.) Make sure that you’ve viewing a heartwood section of the board in question. While white oak has abundant tyloses in the heartwood, it is frequently lacking in the sapwood section.
One related test regarding porosity is to take a short section of oak and try to blow air through the pores. If you are able to blow anything through it at all, it’s probably red oak. Take a look at this video, where a red oak dowel was used to blow bubbles in a glass of water:
httpvh://www.youtube.com/watch?v=eIXZ9iYM4PA
One exception to this rule is chestnut oak, which is still considered to be in the white oak group, even though its pores are open like red oaks.
2. Look at the rays
When looking at the face of the board, especially in the flat-sawn areas, you may notice little dark brown streaks running with the grain, sometimes referred to as rays.
Look closely at the picture above, (click on it to enlarge it if you have to), and note the length of the rays in both types of wood. Red oak will almost always have very short rays, usually between 1/8″ to 1/2″ long, rarely ever more than 3/4″ to 1″ in length. (Pictured above on the right.)
White oak, on the other hand, will have much longer rays, frequently exceeding 3/4″ on most boards. (Pictured above on the left.)
This method is probably the most reliable under normal circumstances, and is useful in situations where the wood is in a finished product where the endgrain is not exposed.
3. Use sodium nitrite
This technique is sometimes used at sawmills if various logs need to be sorted out quickly. Instead of taking the time to analyze each log closely by hand, a 10% solution of sodium nitrite (NaNO2) is sprayed or brushed onto the wood and observed. If it’s red oak, there will only be a small color change, making the wood only slightly darker. But if it’s white oak, there will be a noticeable color change in as little as five minutes, (though it can take longer if the wood is dry, or if the temperature is low). The heartwood of white oak will eventually change to a dark indigo to almost black.
This method is extremely accurate and reliable, though in most instances, it’s probably overkill. However, if you’re ever in a situation where you can’t separate between red and white oak based on anatomy, this method is nearly foolproof. (Though, only the heartwood will bring about the color change, not the sapwood.)
First, you have to obtain some sodium nitrite (NaNO2). You may be able to find some locally through chemical supply stores, but they typically only sell in bulk quantities, making such a small project prohibitively expensive. However, some online retailers have the chemical for sale in much smaller quantities, bringing it into reach of most that are curious about oak identification.
Next, you need to mix up a roughly 10% solution of sodium nitrite by weight. This ratio actually isn’t as critical as it seems: solutions as small as 1% and as high as 20% have all been used with success, but to err on the side of caution, we’ll use the most appropriate quantity recommended.
Recipe for 10% Sodium Nitrite Solution for Testing Oaks:
- 1 cup water
- 4 teaspoons sodium nitrite
Directions: Stir in sodium nitrite until clear. Clearly label solution to avoid confusion; sodium nitrite is very dangerous if ingested.
All that’s left is to simply brush this solution onto a raw wood surface and wait for a reaction. With dried wood stored at room temperature, this reaction should take about 10 minutes. Red oak will be only slightly discolored by the solution, sometimes developing a slightly greenish hue, while white oak will gradually turn a dark reddish brown, eventually turning a deep indigo to nearly black.
See the progression photos below for a better look. (Also note that around the 8 and 15 minute marks the water begins to evaporate from the surface of the wood, but the color is still present after the wood has dried, as indicative of the 25 minute photos.)
TIME | RED OAK | WHITE OAK |
| raw |  |  |
| 1 minute |  |  |
| 5 minutes |  |  |
| 8 minutes |  |  |
| 15 minutes |  |  |
| 25 minutes |  |  |
4. Look at the leaves
This option is obviously only available if you have access to the leaves of the living tree. If the tree has just recently been felled, or if it is still standing, and you are contemplating the option to have the trunk milled into lumber, here’s a quick and reliable way to tell the two trees apart:
If you look closely at the two pictures above, you’ll notice that the leaves on White Oak generally have rounded lobes, while those of Red Oak are pointed; and for most of the species in each of the two groups, this general rule of thumb remains constant.
Why you’d want to tell red oak from white oak
As to the reasons why you’d want to be able to distinguish between the two, most of the answers have been explained above, but I’ll recap:
- White oak is much more resistant to rot, and is suitable for water-holding applications, boatbuilding, outdoor furniture, etc.
- Red oak should only be used for interior pieces such as cabinets, indoor furniture, flooring, etc.
- White oak tends to be more dense, while red oak is a bit lighter and has a more porous and open grain.
- White oak is usually slightly more expensive than red oak.
- White oak has larger and more pronounced ray flecks when perfectly quartersawn and historically has been used more often in antiques than red oak.
Get the hard copy
If you’re interested in getting all that makes The Wood Database unique distilled into a single, real-world resource, there’s the book that’s based on the website—the Amazon.com best-seller, WOOD! Identifying and Using Hundreds of Woods Worldwide. It contains many of the most popular articles found on this website, as well as hundreds of wood profiles—laid out with the same clarity and convenience of the website—packaged in a shop-friendly hardcover book.
Hi I was hoping to confirm the attached is red oak- then again I may be very wrong :) Eric R
It looks like oak, thought it might be stained ash instead. It’s very hard to tell since the stain color could be perfectly hiding the rays, which is what should be at least slightly visible if it were oak.
Hello Eric, I am actively stripping paint from my cabinets (I love wood cabinetry). Once they are all cleaned up, I plan to stain them. Can you tell me what type of wood I have. I think it’s oak but I’m not sure
Yes, oak
Thank you!
Hi Eric, I am having a hard time telling if my oak is white, red, or a combination of both? Are you able to tell the type of oak in my picture? Thanks in advance for any help you are able to provide!
Looks like red oak.
Thanks so much!
Hi Eric…I have stair treads I’m needing to match. I’m thinking this is white oak, but not sure. Was hoping you might be able to tell? The tread is what I’d describe as ‘butcher block’ looking with each of the ‘blocks’ about 2 inches wide. Just trying to get a close match as we will be likely doing a carpet runner with about 4″-6″ exposed on each side and stained. Thoughts? And thank you, in advance!
Yes, white oak. I think in addition to matching the species, it’d be helpful to try to match the grain as closely as possible too.
Thank you, sir!
Hello, maybe you can help me Erik. Would you say this is Tiger Oak?
Yes.
Thank you!
Dear Erik.
I need your opinon, does the picture looks like oak to you? we bought white and red oak for our flooring (like in the short samples), but when it arrive, the color and the patterns of the wood looks so different that we are not sure if they sail us what we payed.
Thank you so much
I can’t tell for sure from the pictures, but I do see large ray fleck, which is characteristic of oak. The oak samples that you have appear to be a weathered gray, which might account for the color difference.
Hi, this is our sanded oak floor from 1951. Was patched and added onto with red oak and it looks so different I’m wondering if it was a mistake. In the last photo you can see the floor change from lighter (new floor) to darker, and the grain seems much busier than the original floor. Any insight? Thanks in advance!
I can’t really make out the transition line very clearly in the pictures. Can you take a closer picture right on the area of transition? Staining the floor can help even out the color, but you have to make sure you’ve done a very good job with your sanding.
Help! Dear Eric Hoping you can help – I’ve just had delivery of what is meant to be a solid oak door with 3 coats of clear sadolin from a local joinery company. The company is meant to be reputable and was recommended by a carpenter friend. Pics are attached showing the door. It’s very solid, but doesnt quite look like the door I was expecting from them. Maybe it’s the coating which is throwing me, but I’m wondering if it’s actually oak – is it? I’m paying a substantial amount of money for it, so want to be sure!… Read more »
Yes, that looks like oak to me. Maybe you were expecting a certain stain or color? I don’t see any issues with the door.
Hi Eric, thanks again that’s very helpful. Yes it must be the staining / coating of the wood. What i was expecting it to look like was the first pic attached here (door with no. 32 by it). I’ve also attached the pic of my door here again so they’re side by side. In terms of getting mine to look like the former, I’m guessing it would be a case of applying a different coating / stain – any particular kind I should use to achieve that? Many thanks
The example of your first pic looks like a totally natural finish with no stain at all. It looks light enough that I’d guess that not even an oil based finish was used, which can slightly darken the wood as well, but perhaps a water based finish with a satin sheen.
Existing floor refinished and some pieces replaced with new material. The old and the new, red oak or white oak? Thank you!
There’s a lot of color variation where it could be either or. It may be a mixture. If you are sure they’re all the same type, would need to get a closer picture of the grain, and especially the rays.
Thank you Eric, I don’t know if they are the same. That really is my question. Is the repair made with the same as the original. See attached close up. Thanks again!
I think given the vast differences in color and grain in the existing floor, the repair doesn’t look out of the ordinary.
I’m trying to identify the kind of wood this dining room set is made out of I was wondering if you had any insights
Looks like red oak to me. Probably done in the 70s or 80s with those black spots all over, a technique known as “flyspecking” and not actually a part of the wood grain.
I bought white oak doors but how can I know? Does this wood look like white oak? I was expecting the pattern and knots to be less in white oak?
Yes, that looks like white oak to me. Is this door still unfinished, or perhaps pickled? Usually the grain lines are dark instead of light colored when finished, so it looks almost like it’s just sanded but still unfinished. Also, I agree that the knot is unfortunate, especially on a raised panel. Nonetheless, it’s white oak.
Yes, it is white oak I figured it out. It is finished with Rubio Monocoat Cotton White. But I think the product was left for too long.
I’m trying to identify my existing hardwood floors. The flooring sample in the first picture is white oak( not matching color ) . The second picture is the existing floor. Do you think my floor is red or white oak? Thanks
I believe your floor is probably red oak. But in this instance, red vs white oak will not make much of a difference because neither your floor nor the samples are a natural color of the wood, they are stained. 95% of this battle will be in finding the right stain color.
thanks. I’m reading this as : Red or white oak will look similar with a dark stain.
Will the coloring effect of the sodium nitrite remain if the wood is sealed after applying it? Or does it go away no matter what?
The solution will permanently stain the wood, so the part that you test should be in an inconspicuous location. You would have to mechanically remove the stained wood either by sawing, planing, or sanding off the affected portions.
Thanks!
Hello can you please help me identify the type of oak this is? I am need to replace some flooring in the house and not sure what the previous owner used.
Thank you
Upper sample looks like white oak, lower sample looks like red oak.
A friend has some red oak for sale. It was salvaged from a courthouse in Florida. Not sure of age or how it’s cut. Haven’t seen it yet; just a pic. Any idea what it’s worth per bf?
Under a loupe one seems to have empty holes, shorter rays and a pinky hue….