Hackberry sawing and drying

How to saw and dry hackberry to avoid chemical staining. March 7, 2000

Recent responses to my question about milling Hackberry lumber, said that this wood had the tendency to get "grey stain" if not properly handled. What is grey stain and what can be done to prevent it? Is grey stain similar to blue stain in pine? I live in N. Florida and plan on air drying the lumber. Will humidity be a factor in grey stain development in the spring and summer months? Any help will be appreciated.

Have your kiln in "drive" when the saw is running... literally. Dry it as soon as it's sawn!

It will definitely stain if air dried.

People who dry this stuff are pretty hush-hush on techniques for keeping it really white.

If you want to some nice Hackberry, simply dry it soon and fast using WOODWEB schedule archives.. Undoubtedly there's something there for this specie.

Maybe the Doc will help with the exact schedule to use and technique???

Start the kiln with at least a 10 degree F depression for 4/4 and 5/4. The stain is oxidation of starches and sugars (much like an apple turns brown if you take a bite and then set it on the table). It is commonly called enzymatic oxidation stain, or just "gray stain" in the sapwood of southern hardwoods.

The blue stain you know is a fungal stain -- the fungus is blue in color. This stain is controlled with a fungicide.

The first step to eliminating the chemical stain is to use a fresh log. Then get it into the kiln within hours after sawing and get the correct kiln conditions within hours.
Gene Wengert, forum moderator

I have air dried some hackberry and being unaware of the existence of "grey stain" and unfamiliar with hackberry, I thought this was the normal color.

Depending on what you intend to do with the wood, I don't see that it is necessarily a problem; tthe grey stain is consistent and, in my opinion, gives the wood quite an attractive appearance.