Food safety and composting

Keep your food safe and still make use of organic waste.

For many around Michigan, it’s that time of year to clean up the yard, put the gardens to bed, and prepare for winter. Have you ever wondered what happens to all that yard waste? Well, it depends on where you live, but Michigan banned yard waste from entering landfills back in 1995. For some, yard clean-up means starting a new compost pile. Composting is a great way to recycle and re-use valuable nutrient-filled materials that would otherwise go to waste. For more information on how to start composting, contact your local MSU Extension office or visit the Michigan State University Extension website on composting and reclycling.

When it comes to backyard composting, one of the most-asked questions is, what things can I or can’t I put in it, and there are lots of conflicting answers out there. Well, the answer is that you can technically put anything organic in it. What is organic (not to be confused with Certified Organic products you see in the grocery store)? The dictionary defines organic as “derived from living matter.” So that basically means anything that is or once was living can be composted- plants, trees, branches, fruits, vegetables, flowers, insects, cotton clothing, dead animals, beer, wine, table scraps, toiletpaper rolls, Kleenex, paper plates, etc. Wait…dead animals? Everything you’ve probably heard about composting says absolutely no milk and dairy, eggs, or meat of any kind. Technically you can compost all of those products, but they do pose food safety issues, and are not recommended unless you’re an experienced, dedicated composter. Although they are organic materials, dairy, eggs, and meat (all kinds including fish and poultry) are animal-based, and can harbor dangerous bacteria like Salmonella and E. coli., which can grow and spread through your compost, and possibly get onto your fruit and vegetables later on and cause a food safety risk.

The best way to prevent growth and spread of dangerous bacteria in your compost is to simply not include these animal-based products. If you do decide to be a dedicated composter and want to include these table scraps, there are some basic rules to follow:

  • Make sure any animal-based products are buried in the center of your pile. This will prevent rodents/pests from digging them out for a snack.
  • Make sure your pile is big enough to activate the hot composting process- minimum of 3’x3’x3’.
  • Follow strict “hot composting” methods, which means reaching an internal pile temperature between 130 degrees Ferhenheit-160 degrees F for  five days, and repeating this heat cycle three times. This will ensure that dangerous bacteria are killed.
  • Use a good thermometer to measure temperature. There are many on the market specifically made for compost piles. Reaching proper temperature is the most important part of the process and having the right tools makes it easier and safer.
  • Stir your pile. Stiring facilitates the heat process and adds needed oxygen. Piles should be stirred/turned after each high temperature cycle, when the temperature starts to level out.
  • If compost doesn’t reach the proper temperatures in the proper cycle, it must be treated as “raw” compost and shouldn’t be spread on food crop areas within 150 days of harvest.

Another common question is, can I compost over the winter? Of course! Although the process may be a little slower, your compost pile is actually warm/hot all winter long if it is managed properly. That’s why fall yard clean-up is so important- your pile needs food for the winter.

The most important thing to consider in composting is how much work you want to put into it. If you want something low-maintenance, Michigan State University Extension recommends sticking with plant-based material only. That way there’s little worry about food safety issues. If you want to significantly reduce your waste, and don’t mind a little more labor, you can compost just about anything organic-based. 

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