Cleaning Wood Knife Blocks

[Richard Kilgore]

Someone told me that it is bad to clean a wood knife black by my method - blasting shower water through the slits to clean out the accumulation of dust and kitchen grime from time to time. He says it will raise the moisture level in the wood and make it split eventually. (I have so far had no ill effects that I can tell from doing this.) In addition, he says he has never cleaned his blocks because they never get dirty on the counter across and away from the range top. Is that even possible?

So is there a good way to clean wood knife blocks? More and less damaging ways? How do you do it? Or do you not?

[Pierogi]

I have to say, I have never even given a thought to cleaning mine. I have one of those Wusthoff blocks that are horizontally mounted under a cabinet, and moves on a pivot-base, which is screwed into the bottom of the hanging cabinet. The knives are clean when I put them back in the block, and the orientation of the blades/block, at least in my mind, doesn't lend itself to catching schmutz in the grooves. I do, very periodically, VERY, dust off the flat top surface of the block when its swung "out" so I can see it, but it is way down on the priority list.

That said....when I had a traditional, counter-standing block, I still didn't think to clean out the grooves. Again, the knives were clean when I stored them, the bolster/handle of the knife mostly blocked the opening of the groove, and I used to store the knives edge side up, so that the spine of the blade was the only part of the knife actually touching the block.

The flat, sloping surface of the top of the block *would* get grungy periodically, and I'd wipe it down with something hot and grease-cutting, but I never, ever thought to clean the inside.

Of all the things to clean in a kitchen, that just was never on my radar, and actually, probably never will be.

[baroness]

This may be another job for canned air (with the slender extension tube).

[xxchef]

Wood knife blocks are a BIG no-no in commercial kitchens (along with most things made of wood) and for good reason... they cannot be satisfactorily cleaned and sanitized. Despite all best efforts there is no way to completely keep dirt, grunge and food from getting in all those nooks and crannies. All it takes is for one knife to be put away in it one time that is not completely sanitized and dry (and I don't mean just wiped clean) and the block is innocculated for life.

That said, they are quite common in home use and you surely don't hear about people getting sick from their knife blocks! I think I'd pour some boiling water through it to clean, followed by a 100-200 ppm solution of bleach (lots less strong than you think), air-dry thoroughly then rub down with mineral oil or other non-toxic oil (don't use vegetable or animal oils which will get sticky and/or rancid over time) to restore and protect the wood finish/appearance.

[paulraphael]

Obviously, only put knives away clean. Then this won't come up often.

When grunge appears, I've taken small wads of cloth soaked in sanitizer and shoved them all the way through with a round-tippe knife or a hack saw blade. On most blocks, the slot goes all the way through to the botom.

[David A. Goldfarb]

After reading this, I looked around at some of the restaurant supply sites, and there aren't many knife blocks out there that aren't wood, at least not in the traditional form of a knife block. F. Dick makes an ABS plastic block designed for easy cleaning, but it's not very large. There's that stainless thing with the freeform plastic rods bundled inside, but that looks very hard to clean and gets kind of ambivalent reviews. There are magnetic strips of course, if you've got the kind of space where that works, and there are stainless steel or plastic knife racks, some with inserts that can go in a dishwasher, but they require clearance above the rack to remove the knife--perfect for the side of a butcher block or the edge of a table, but that wouldn't work in our current kitchen.

We have low cabinets that go all the way around the kitchen and not a lot of conveniently positioned wall space near the cutting board, so I've got three blocks, two of which are stacked and glued together, and a 12" mag strip for knives too big for the blocks. As much as I like the look and feel of wood, I'd like to consolidate the three blocks into one larger one at some point, and something sanitizable would be of interest.

[Chris Hennes]

Repeatedly letting wood absorb a lot of water and then dry out will have a tendency to cause the wood to crack, yes. That said, I think you probably do this infrequently enough that it doesn't really matter. You will want to make sure to dry the interior thoroughly to prevent mold from growing in the slots, however. From a food safety standpoint wood is a mixed bag: it's difficult to completely sanitize yourself because it is so porous, but it tends to kill bacteria on its own by absorbing the water from their cells (see the fairly extensive research on wood cutting boards for more details).

[weinoo]

Repeatedly letting wood absorb a lot of water and then dry out will have a tendency to cause the wood to crack, yes. That said, I think you probably do this infrequently enough that it doesn't really matter. You will want to make sure to dry the interior thoroughly to prevent mold from growing in the slots, however. From a food safety standpoint wood is a mixed bag: it's difficult to completely sanitize yourself because it is so porous, but it tends to kill bacteria on its own by absorbing the water from their cells (see the fairly extensive research on wood cutting boards for more details).

I agree with Hennes. I've "cleaned" my wooden block a few times by running really hot water through the slots at a decent enough high pressure, and also scrubbed the outside of the block with a scrubbie and dish soap, followed by a hand and then air drying. No ill effects to the block, and I've had my current most-used block for a number of years.

I mean, how dirty can this thing possibly get in the home kitchen?

[Shalmanese]

I wonder if pressure steaming would be an effective way of sterilizing them. Put an inch of water at the bottom of a pressure cooker, add a cake rack and put the knife block on it so it's not touching the water. Bring it up to pressure for half and hour and then let it cool down naturally. The temps should kill any living thing. Would that harm the block?

[Dakki]

I'd be worried about the glue. Not sure what kind they use in knife blocks but the combination of heat and humidity can break down resins, and epoxies start losing cohesion around 40 C (from memory).

[Chris Hennes]

Right, the glue is going to be a problem at those high temperatures. Frankly I wouldn't worry about "sterilizing" a wooden block: as I mentioned above, wood is pretty good about killing bacteria all on its own simply by absorbing the water out of their cells. And once you start letting the interior of those slots get wet and build up a high-moisture environment you are actually creating a very nice habitat for various sorts of bacteria unless you have a good way of drying them back out. That's the reason you should be sure your knives are completely dry before storing them in a slot-type rack.

[OliverB]

Ha, I never cleaned mine, never even occurred to me. But I doubt that washing it once in a blue moon would do much damage. I threw mine out and got 3 magnetic strips at Target (around $15 each I think) and now all my knives are on the wall and out of the way. More counter space, more room for knives - actually my main reason to look for something, as I got some butcher knives and the block was full. And it looks a lot nicer to me.

But look how often you wash a wooden cutting board, and in all these years I've only had one split along a glue line (was made of several strips of wood) a tiny bit. At that rate, I'd guess that your knife block won't crack until your great great grand children have it in use

I did occasionally put some cutting board oil on it.

[Richard Kilgore]

It was a comment here a few years ago that got me to clean my wood knife block the first time. I was skeptical. I always hand wash my knives and dry them before putting them back in the block, and I could not see anything down in the slots. But when I flushed the slots with shower water I was amazed at the gray-oily-debris that came out from 20 years of counter service. This was clearly just kitchen air dust and oil accumulation. If dust falls everywhere else in the house, why would I think it would not find its way into knife slots over the course of many years?

[David A. Goldfarb]

One thing that I just noticed is that on some knife blocks (one of my wooden blocks and the F. Dick plastic one), all the slots are open to the outside surface, so they are much easier to clean and dry--

http://www.instawares.com/f-dick-plastic.fdi-8801001.0.7.htm

I would look for that on any future knife block purchase.

[Edward J]

I wonder if pressure steaming would be an effective way of sterilizing them. Put an inch of water at the bottom of a pressure cooker, add a cake rack and put the knife block on it so it's not touching the water. Bring it up to pressure for half and hour and then let it cool down naturally. The temps should kill any living thing. Would that harm the block?

Wood is a living thing, it absorbs moisture when the enviroment is humid, and shrinks when the enviroment is dry. The age of the wood plays no role in this, I've worked with 1o0 yr old oak timbers reclaimed from a frmhouse and they still move in accordance with the seasons and humidity.

If you "steam" the block, the wood will expand and will stress out the glue lines, fatigueing usually occurs beside the glue line, not on it.

All that being said, check out my favorite hardware store: Lee Valley (www.leevalley.com) There you will find magnetic bars faced with wood, and knife blocks filled with thousands of plastic rods about the size of very fine spaghetti--you slide the knife inbeteen the plastic rods, the knives never touch and the whole assembly of plastic rods comes out in one piece and can be washed. But no one ever said you couldn't do the same with a cannister filled with bamboo skewers......

[dcarch]

To clean and sanitize the slots: Do not use bleach, it can discolor wood.

 

I use mouth wash full strength to soak the slots for a few minutes, then turn it upside down and blast with a dental water jet.

 

I don't use a knife block anymore. Too many knives. I use rare earth magnets to hang the knives by the very tip, the entire blade touches nothing

 

dcarch