Cooling Colostrum as the Weather Heats Up

Many dairies will cool their colostrum outdoors in the winter. It makes perfect sense, you don’t have to warm up the freezer, you don’t have to take up space, the bags can dry out from being in the pasteurizer, it cools it quickly (depending on the outside temperature, of course), and it uses less energy. As the weather heats up, consider how long it is taking for your colostrum to cool, whether that be in the fridge, freezer, or outside.

Cooling colostrum quickly is one of the most important pieces of colostrum management, as this is the portion of the process that slows the growth of bacteria. Most of the dangerous bacteria that we deal with on dairy farms THRIVE at temperatures of 68 and 100 °F How much time is your colostrum is spending time sitting between those temperatures as it gets warmer outside?


There are three pieces to this equation. How you are processing, how you are cooling, and how you are storing?

How are you processing?

Are you taking colostrum straight from the cow and putting it into the freezer? This colostrum will start to cool immediately after hitting the cool (lower than body temperature) bucket/bottle/bag, but it will quickly slow the cooling process, and sit in the “danger zone” if not moved to a refrigerator or freezer immediately. Even if you let that colostrum sit for just 20 minutes to milk the rest of the fresh cows, you have already doubled the bacteria load of your colostrum.

The cooling game changes a little when you pasteurize colostrum. When that bag comes out of the pasteurizer, it is at least 105F. While that isn’t much hotter than when it comes out of the cow, it likely won’t be transferring containers, which is where a significant amount of cooling comes from (up to 15F if being transferred to a cold container). This milk will take more to cool down, and it will sit in the danger zone for a longer period if not put in the fridge or freezer immediately.

Lastly, consider what is happening to your colostrum if you let it sit out at room temperature while you pasteurize multiple batches of colostrum. That could be over an hour of sitting out at room temperature, meaning the bacteria would have the opportunity to grow by 8x!

How are you cooling?

There are a few cooling options. You can use a fridge, freezer, or even outside in the right conditions. The larger the gap in temperature between the colostrum and the cooling unit, the faster it will cool, and the less time it will spend in the danger zone. Keep this in mind when considering which route you want to take to cool your colostrum.

How are you storing?

At room temperature, colostrum is likely ruined after sitting out for 1-2 hours. At 2 hours, bacteria has multiplied over 64x. Depending on what it started at, that could be a huge problem for your calves.

In a refrigerator, colostrum can stay preserved for a few days. This being said, we are working on some pretty awesome things that may change this! Untreated colostrum will only be good for 2-3 days maximum.

Frozen colostrum can be stored safely for up to one year. If you are looking to build a colostrum bank, this is the way to go!

Well, that’s scary. How do you keep your colostrum out of the danger zone?

  1. Don’t leave colostrum to cool outdoors if the high for the day is going to be above 40F. It will take too long for it to cool.
  2. Freeze/refrigerate colostrum in small batches and in properly proportioned containers. Do not try to put a 5-gallon bucket of colostrum in the fridge, hoping it will cool at the proper rate. The milk in the center of that bucket will be in the danger zone for much longer than it should be. Instead, consider one-gallon volume per container maximum.
  3. Ideally, keep the liquid as flat as possible. The more surface area you can expose the colostrum to, the faster it will cool. It will also heat quickly (this is our favorite part of our coloQuick machine!)
  4. Don’t let colostrum set out at room temperature in a bucket between pasteurizing batches. Bag colostrum immediately, and allow it to set in the fridge or freezer for the wait time.
  5. Keep a very close eye on colostrum quality in terms of cleanliness. Plate various samples at different points in the process from different animals to help find areas of opportunity in your colostrum program.

These are just a few general ways to keep your colostrum out of the danger zone. Each farm is unique, and some of these ideas won’t work for your maternity program, and we understand that!

If you would like to improve colostrum handling and improve your colostrum program as a whole, send us a message. We are very passionate about colostrum and maternity pen management. We know we can make a difference in your calf program today by creating a custom plan for your farm that works for everyone, employees and calves alike.

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