Bacterial cultures are the key to cheese making.  Almost all cheese needs to have some sort of bacterial culture added to it.  These bacterial cultures not only give the cheese its flavor, but also acidify the milk, which aids in the coagulation of the curds.  Examples of cheese that can be made without cultures are Queso Blanco and Ricotta.  These are acid precipitated cheeses, and are quite bland.  It is the bacteria consuming the lactose (milk sugar) in the milk and excreting lactic acid that acidifies, or ripens the cheese.  This ripening is the basis of the long-term keeping quality of cheese.

Basically, there are two types of cultures: thermophilic (heat loving) and mesophilic (moderate temperature loving).  There are also many variations on these cultures, such as goat cheese mesophilic and fresh cheese mesophilic.  Each culture will give the cheese a different flavor, but the handling and preparation of the cultures is the same.  Buttermilk is a mesophilic culture and can be used as such.  Yogurt is a thermophilic culture and can be used to make cheese that calls for a thermophilic culture.  But if you're real serious about cheese making, you can culture your own true cheese starters or use DVI cultures.

Direct Vat Inoculates or "direct set" cultures that can be added directly to the milk with no need for reculturing.  This is easier, but can be more expensive because they cannot be recultured.  At first I avoided using DVI cultures because of the expense and I try to make everything "from scratch".  But, I found that if you buy your DVI cultures in "bulk", they really aren't that expensive and the ease of use and consistency in quality of product they produce are worth it.  The best place I have found to purchase DVI cultures is from The Dairy Connection.  See Culture Sheet below for more info on which DVI cultures I use. 

If you want to try reculturing your own culture see below.  Remember that you cannot reculture DVI cultures, you must buy a "regular" culture to prepare your mother culture.  Also remember, the consistency of the quality of your culture will change. there is no way you can keep all contaminates out of your recultured cultures.  I have kept my cultures going for two years with no problem, but I must admit I now use DVI cultures exclusively.

I store all my cultures, lipase powders and molds in sterile jars in the freezer.  Kept this way, they will last for over a year.

The following charts refer to products available from The Dairy Connection. Since these products are really meant to be used in large commercial batches I have worked to calculate the correct amounts for smaller batches. This cart was originally made up just for my own personal reference. The recommended amounts of each culture to use (given below) is based on my own research and experimentation with these particular products. These amounts were not supplied by the supplier, but are what I find works correctly with my recipes.

I do get a lot of people who ask me what cheesemaking cultures I use, how I use them, and where I get them from.  I use these cultures exclusively because they are very high quality and also the most economical if compared to other cheesemaking suppliers. If you need more help, and have questions about these cultures, molds and lipase powders, you should contact The Dairy Connection. They are extremely nice and helpful and can advise you as to which of their products would be best for your projects.
E-mail: getculture@ameritech.net
Phone: 608-242-9030

IMPORTANT information for ordering cultures: Please note that with the Dairy Connection cultures, etc. they say "dose" and "unit". These references are for large producers making 1000 gallon batches and they don't really apply to home use. Each package will make many cheeses and is much more economical compared to getting cultures from other suppliers like New England Cheesemaking.

You will need to purchase your first culture from a cheesemaking source, but if you're vigilant, you'll be able to reculture all the starter you'll ever need from this first source.

Please note: you cannot reculture DIV EZAL cultures I discuss above. You need to get "regular" culture starters for making reculturing.

When you receive your cheese culture it will be freeze dried in a little envelope.  Store this in the freezer until your ready to create your mother culture.  Making the mother culture is a lot like making yogurt, except you really must be careful that everything is sterile.  You should be clean when making yogurt, of course, but if the yogurt becomes contaminated with stray bacteria, you just loose that one batch of yogurt.  If your mother culture gets contaminated it could effect dozens of cheeses, and you may not even find out about it for months down the road.  Preparing mesophilic cultures and thermophilic cultures is the same except for the temperature at which you add the freeze-dried culture and the incubation time and temp.  You should use skim milk to prepare your cultures, and since I don't have a cream separator for my goat milk, I just use powdered milk.
 

This covers just one jar, but of course you can prepare more than one jar at once.  Add 1 ½ C. powdered milk to a sterilized quart canning jar.  Fill to within 1 inch of the top of the jar with water, cover with a sterilized lid and shake well.  Let it set 15 minutes or so and shake well again.  Put the jar in your canner with the water level at least ¼ inch over the top of the jar.  Bring the water to a boil and let it continue to boil for 30 minutes.  Remove the jar and let in cool.  This is where mesophilic and thermophilic cultures differ.  Let the meso cool to 72°.  Do not open the jar and put a thermometer in it to check the temp!  This will contaminate your starter.  Instead, this is what I do.  After the milk has cooled to about the right temp (You can tell by feeling the jar, it will be slightly warm) I take my little "six pack" cooler (without lid) that I use for yogurt making and I place the jar inside.  Then I fill the cooler with water that is 72°.  I leave the thermometer in the water in the cooler so I know it's 72°.  I feel the jar occasionally, and when the jar feels the same temp as the water, I know the temp inside the jar is correct.  For thermophilic culture use the same technique, but make sure to have the temperature of the water be 110°.

When the starter culture milk is at the right temp, quickly open the jar, add the powder culture and close the lid.  Shake the jar well to make sure the powder is dissolved and place the jar back in the cooler with the proper temp water (72° for meso, 110° for thermo).  Cover the cooler with a fluffy towel and let it sit undisturbed.  Mesophilic culture will take 15 to 24 hours to ripen.  You will need to replace the water a few times to make sure it stays at the proper temperature.  Thermophilic culture will take 6 to 8 hours.  The cultures are done when they have a yogurt-like consistency.

When the cultures are done, place them into the fridge.  They will keep there for about a week.  You probably won't use them up that fast, so do what I do and freeze the culture.  Sterilize a couple of ice cube trays.  Shake the jar with the culture real well to liquefy the culture and then pour it into the ice cube trays and place the trays in the freezer.  When the cubes are done, remove them and put them in a labeled ziplock bag and store it in the freezer.  It will keep for a few months in the freezer.

The nice thing about freezing the culture in ice cube trays is that the culture is then in nice convenient one ounce servings (each cube equals one ounce).  When it's time to reculture again, you can use pint jars or quart jars; you just add one cube to a pint jar and two cubes to a quart jar.