Australia's Science Forum

Received this question this morning from another Lab Tech....
"Science focus 2 for Year 8. Making cottage cheese page 75. I need rennin,ie can use junket tablets but what exactly do they mean by “culture of microbes” … "
Any one out there able to help?

Culture means to grow & Cultivating cells, Tissues, Bacteria, Fungi, Moulds & Yeasts. Very much like Agar Plates. Microbes I guess would mean very small, Microorganism, can only be seen with the aid of a microscope.

I am not aware of that prac with Cottage Cheese, do let us know how it goes.

What can be used for this culture though?

Perhaps it is the microbes naturally occurring in the cheese? Like in yoghurt?

"culture of microbes" you need to 1/2 teaspoon of plain yogurt this will help the milk & junket to form the cheese.

We do a similar prac. Junket tablets are very hard to come by these days, but Southern Biological sells junket powder. The culture we use is Streptococcus lactis, but we've had it a long time and I don't think Southern Biological routinely stock it. They may be able to suggest an alternative. Otherwise, if you are near a cheese factory, they may be able to give you a starter culture. A lot of yoghurts have bacteria in them. You could use a teaspoonful of yogurt to start it off, though technically you'd be making yoghurt not cheese. We also use lemon juice to produce curds, strain it through Chux cloth and call that cheese. Good luck!