Many of us have a wooden cutting board on our counter top or stashed in our kitchen cupboards somewhere, and we butcher more than meat on it- salads, carrots, and scraps all get worked on (and into it). The value of a "butcher block" is the very fact that wood is hard enough to work on but soft enough to allow knives and sharp tools to be used on it and even pierce it, without dulling the knife or chipping the block. Hence a block surface has only an oil treatment- none of the usual wood finishes like varnish or paint can be used on it. So the blows of our preparation instruments aren't the only thing it absorbs- food particles, fats,meat and vegetables, juices, etc. can soak in and provide a fine encouragement for bacteria growth and odors. This is one of the reasons most professional meat cutters now use plastic (nylon) cutting boards. They are much easier to disinfect. A block should always be disinfected after cutting raw meat on it to keep any bacteria left behind from infecting foods. A plastic cutting board is the best choice for the home, because it can be put right in the sink with hot, soapy water.
If you do use a wooden block to cut on, here's how to care for it. Since most chopping blocks are made of tight-grained wood, moisture and food residue can't penetrate easily. but it's best to remove any food residue as quickly as possible after cutting. Then give the board a quick wetting and thorough wiping with a solution of plain old dish-washing detergent and water. This method will go a long way toward keeping the board clean. Don't let the water set too long on the board. or it will soak in and swell and raise the grain of the wood-it could even split the block down the middle. So, wipe it down quickly with a clean cloth.
Don't let your block's surface get too crisscrossed or you will just be providing underground canals for germs.
To disinfect the board, use a solution of two cups of water with teaspoon of bleach added -wipe down the board and rinse.
To keep your block from getting brittle and help heal it's aches and pains from being beat on, treat it like an athlete - give it a good rub down from time to time. Mineral oil is the best thing to use, it's nontoxic; it never grows rancid. Never use linseed oil, and animal fats-bacon grease is out too. Apply the oil generously with a soft cloth when the board is good and dry, rub it in and let it set for at least half an hour. If it's been a long time between oilings, you might want to repeat the process. or leave the oil on overnight. Then blot away any excess and rub the block dry. This will condition your block and keep it "chop chop" for quite awhile.