Monday, October 18, 2010

How to Make a Mesophilic Starter Culture

Sometimes a cheese recipe will give you the option of using a starter culture, rather than a direct-set starter. Here is how you do it!

  • Sterilize a clean 1 litre mason jar and lid in boiling water for 5 min. Cool, then fill jar with fresh skim milk leaving a ½ inch head space. Secure lid firmly into jar.
  • Place the jar into canning pot and fill with water to the same levels as the milk in the jar.
  • Bring the pot to a rolling boil and hold for 30 mn
  • Remove jar of sterile milk carefully from the canning pot and allow to cool to 20-22 C or 72 F. To check if the milk in the jar is adequately cooled, hold the jar next to your cheek and it should feel tepid or just slightly warm. It takes about 6-8 hrs after removing from hot water bath.
  • Innoculate the sterile milk by adding 3/8 tsp of the freeze dried mesophilic starter culture to the 1 litre mason jar of sterile milk. Sprinkle the culture evenly on the surface of the milk and quickly re-secure the lid. Allow the culture to dissolve for 2 mn and gently agitate the culture into the milk until fully dispersed. To ensure the culture is adequately mixed, look at the bottom of the mason jar to see if there is any yellow granules. If so, continue to rock the jar until they have disappeared, as this represents culture powder that has not dissolved into the milk.
  • Place the jar in a warm place where the temp. is stable at 72 F or 22 C, up as high as 77 F or 25 C. Keep it there for 12-24 hrs until the milk has thickened. The most ideal location is in the cupboard over the refrigerator, the jar wrapped in a hand towel.
  • After 12 hrs from the time of innoculation, check to see if the milk has coagulated or thickened. This usually takes about 16 hrs under favorable conditions but it can be sooner if the temperature is warmer. When the culture has the consistency of a good firm yoghurt you have reach the coagulation point.
  • Chill the culture immediately by placing the jar in the fridge. It will keep as a fresh active culture for 3-4 wks. The fresher your culture the better your cheesemaking results. The culture can be used for cheesmaking right after the coagulation point is reached. 10 grams of mesophilic culture can be made into 10 litres of mother culture. Do not freeze your prepared culture!!!
  • Keep the unused portion of your culture package in the freezer where it will remain active for 3 years.
  • It is not necessary to prepare a culture in order to make cheese. The freeze dried cultures can also be used as a direct set culture at the recommended rate of the recipe. You can prepare cheese by adding the powder into your cheese pot or vat for direct inoculation.
  • The above procedure can be used to prepare mesophilic and aroma cultures only.

information from Glengarry Cheesemaking Co. 


girlichef said...

Awesome Info!!! Thanks for posting this, N!!

Rebecca said...

Thank you for this! I thought I had read elsewhere, though, that you *can* freeze the prepared culture. Maybe not. I'll have to investigate more. I know that I did read that, if you are making a prepared culture with goats' milk that the thickening of the culture will be less than that with cows' milk. It will be more of a runny yogurt than a firm yogurt.

Annie said...


I have some questions about the milk, though. I have access to raw milk- can I use that instead, or should it be pasteurized? Also, where I live it is very difficult to find skim milk (in Italy), so can it be part skim or whole?

Natashya KitchenPuppies said...

Hi there,
I think raw milk is always preferable in cheese making, you are bringing it up to temp anyway.
If you don't have the same fat content as the recommended one in a recipe - just go with whatever is closest. (I would go slightly up, rather than down, in fat content)