The first stage in cheese making is to ripen the milk. In this process, milk sugar is converted into lactic acid. Cheese makers use starter cultures to control this ripening process. The same cultures are used for cow's, goat's and sheep's milk. For more questions and answers about cultures at our blog, >click here.
Some of our cultures have other uses besides making cheese. For example, they are used to make Kimchi (recipe here) and soy "cheeses" (recipes here).
What are starter cultures?
Cheese cultures are combined single strains of bacteria that were isolated many years ago from cheese dairies producing great cheese. They are currently maintained as pure strains by the culture companies we buy from. There is no animal tissue derivation, they are non-GMO and they are gluten-free. The milk substrate on which the cultures are propagated contains no growth hormones (RBGH).
If kept frozen, our cultures will last up to two years. At room temperature, they will last up to two months. We have found that they survive extended shipping times to even the warmest climates.
Can I use buttermilk or yogurt as starters?
The problem is that you rarely know what the culture mix really is, since that can change substantially on the trip from the dairy to your home. Also, you have no idea how healthy it is, due to temperature and storage conditions.
In making cheese, it is essential to start with a healthy known culture source because if the culture is not strong enough, the fermentation can be just as easily done by an ambient bacteria from the surrounding environment. As most of you know, this is not always best for our health and well-being. This is also why we see such rigid sanitizing practices at dairies.
Buttermilk from the store seems to be an especially unpredictable culture source. Sometimes it works and sometimes it doesn't. You are certainly best off using the proper cultures for each recipe.
Do I need to use cultures with raw milk?
Yes...You can sour the milk with the natural flora from the animal, however what you get is going to vary. People used to make cheese this way but they also made a lot of bad cheese. If you were to try this today it would require using very clean milk and it would take several trials to select from the best for flavor (many of the samples would just be sour milk). Then, it would be up to you to maintain this culture.
We use raw milk much of the time and we have done this with success and failures. We have found that the ideal program for raw milk is to slightly ripen it before adding a smaller dose of proper dried culture. This will ensure that the milk gets going with the proper acid producers while the natural ones work in the background, once the cheese goes into aging.
We cover this in our advanced workshops. (To see a blog article about these workshops- click here.)
How do I decide which cultures to buy?
Our recipes specify which kinds of cultures to use. Thermophilic cultures are for cheeses scalded to higher temperatures (104-140F) and Mesophilic cultures are for those never exceeding 102F. Your choices are between the large packs and the small packs, (direct set or re-culturable). There are pros and cons to each, so we recommend that you read the following sections about cultures before making your decision.
How can I tell whether my cultures are still good?
You can assume that our cultures are still active if they have been stored properly in the freezer for up to 2 years. When your culture is active it will coagulate your milk when left out overnight.
When using a mother culture you will be able to tell in the preparation, because if the bacteria are not active, your milk will not thicken overnight.
Measuring the acidity is the most accurate way to test your culture. After adding a starter culture to your milk, the acidity will slowly begin to rise. (See our blog article,
Using a pH Tester)
Small Culture Packs
Over 30 years ago, when Ricki Carroll started this business, there were no cultures or enzymes available in small enough quantity for home cheese maker. Ricki wanted to teach folks how to make cheese, so, she had the cultures put into small enough packets to ripen one gallon of milk at a time.
Can I split the packets?
Each of our small packets sets up from 1-4 gallons of milk, depending on the type of milk and the type of cheese being made. Follow the recipes, and if your cheese shows signs of excess acidity or if you want to ripen less than one gallon of milk, you may split the packets.
To split the packets, take a clean piece of tinfoil (right off the roll so it is sanitized) and dump the contents of the pack into a neat pile in the center. Then take a very clean knife and separate the pile as evenly as possible into two parts. One part goes into the milk that is ready for culture. Put the other half carefully back into the pack and roll that up with as little air as possible. Secure it in a zip lock bag to be used again within a month or two.
Note: Some of the soft cheese cultures have small amounts of vegetable rennet in them. Because of this, we recommend using them all at once.
Some of the recipes in your book and on your website call for prepared starter culture. Can I use direct set packets instead?
Yes. One pack of direct set culture can easily be switched for the prepared starter. Also, you may use the re-culturable packets as direct set if you need to. (The direct set cultures with rennet added are not re-culturable.)
Instead of using a direct set or a prepared starter, can I freeze some of the current batch to use later?
We don't recommend freezing it because there is too much stress on the bacteria and the possibility of ambient contamination. The best alternative to using starter is to put 1-2% of a live culture from the current batch into fresh milk.
Why do some of the soft cheese cultures have the same ingredients as others? Are they different?
Yes. The balance of the amount of bacteria in relation to the amount of rennet varies.
Why does the website say to use Fresh Culture for some cheeses, but your book says to use Mesophilic for the same cheeses?
Our Fresh culture is a type of Mesophilic culture. It is meant to be made into a mother culture before using, but we have had luck using it as a direct set culture also. This culture is quite different from our normal Mesophilic which is a simple culture compared to the Fresh. Using the Fresh culture will produce a more open curd (with small holes due to carbon dioxide production) and a buttery flavor.
How do I decide whether to make a mother culture or use direct set packets?
For most purposes, we recommend using the direct set cultures. When you use them, you are sure of the amount of culture activity you are getting. When you make a mother culture, you are exposing the culture to the freezing and thawing process which affects the balance of bacteria.
Mother cultures are fine if you are making cheese every 2 -4 days. They will last for a month or so, but the problem is that even when they are still alive, they are not necessarily in optimum condition to out-compete other bacteria that may get into the milk.
How much prepared starter equals one pack of direct set culture?
One pack equals 2-3 ounces of prepared culture. If you freeze your mother culture in ice cube trays, one cube is one ounce. So, two cubes equal one small pack of culture. (Basically, the prepared starter should be 1-2% by volume of the milk used.)
What if I can't get skim milk to use for my mother culture?
You may use 2% milk or nonfat dry powdered milk. If you have raw milk, you can let the cream rise to the top and skim it. (We do not recommend using full fat milk because the bacteria tends to rise with the cream and does not get incorporated into the inoculation dose.)
How thick should my prepared starter be?
Starter made with cow's milk will be similar to yogurt when it has cooled down. Goat's milk will be similar to buttermilk when it has been cooled.
If your starter separates, drain the whey quickly and get the curds right into the refrigerator. It probably developed excess acid and it may have a sharp flavor. Next time, let it set for less time before cooling.
If your starter forms lumps, break it up into a smooth paste before using. If the lumps are very hard, it means you have allowed the mother culture to acidify too much.
My prepared starter doesn't work.
If it is older than a month, it has probably been contaminated. Mother cultures need to be re-cultured regularly. The time your culture will last can be from 3 days to 1 month, depending on the milk and the conditions.
If it is new, there could be any number of reasons:
The target temperature wasn't maintained while ripening.
The inoculating culture had expired or you didn't use enough.
The milk contained antibiotics.
There was residual bleach or detergent on your containers or utensils.
The starter had been contaminated with competing bacteria.
6. My prepared starter tastes bitter.
It is always a good idea to taste your prepared culture before freezing it. If it tastes bitter or acidic, it has over-ripened. Next time, use a little less starter or incubate the milk at a temperature two degrees lower.
My prepared starter has bubbles in it.
Prepared starter from Fresh Culture or any of the cultures with diacetylactis or m.s. cremoris (such as Flora Danica) will have many little gas holes. Otherwise, if your starter has bubbles in it after you have cooled it down, disgard it. It may mean that gas-producing organisms like yeast or coliforms have contaminated it. Re-sanitize the area and if you were using raw milk, switch to powdered milk.
You may have noticed some differences in our yogurt directions regarding the amount of milk one packet will set. The reason for this is that they are all correct, but different. Each packet sets 2 quarts of milk in 6-12 hours. If you let it set longer(18-24 hours) each packet will set up to one gallon of milk. The longer the set, the more acidic the yogurt, so if you like it to be sweeter, you should choose to set 2 quarts in the shorter time.
For more questions and answers about yogurt at our blog, click here
How do I use my Yogotherm?
There are many ways to keep your milk at ripening temperatures, however, most folks find our Yogotherm to be the easiest. If you plan to set your milk for long periods, we would suggest doing a pre-heat of the container at about 120F (which is usually your hottest tap water). Dump this when your milk is ready and close up immediately. To clean the Yogotherm, simply remove the inner liner, wash and dry.
Can I re-culture the yogurt cultures?
Yes, if you are inoculating the fresh batch with another batch that is only a week or so old. However, in time, the culture balance will change and the yogurt will become more and more acidic. We recommend re-culturing only once or twice before starting with a new packet of culture.
Which culture is best for making Greek-style yogurt?
They all work well for this. Simply strain the yogurt in butter muslin or a yogurt strainer until it is as thick as you wish it to be.
I am allergic to cow's milk and there is dry milk powder in the culture packets.
Yogurt cultures contain miniscule amounts of dry milk powder-less than .01%. It is consumed by the bacteria since it is there to provide fuel to get them started from their dry state.
What is the difference between the I. bulgaricus in your Bulgarian yogurt and the other kinds of bulgaricus in your other yogurt cultures?
None of them are single strains. They are all different complex strains of bulgaricus.
Can I use my favorite yogurt (which has probiotics in it) as a starter?
Yes, you can re-culture or add an element from one yogurt to another batch. However, the problem is that since these cultures rely on a balance, and it would be very difficult to keep this balance, the final product will be very different from the original. Also, you will have no idea which cultures were active.
For example, our Bulgarian style yogurt is a good one to re-culture because the two primary cultures work well together, but if you added another culture to that, it would probably get squeezed out due to their strong competitive nature. With the introduction of more and more probiotic cultures (bifidus) the yogurts have become more complex.
If you are looking for probiotics, our
sweet yogurt culture contains acidophilus and bifidus. For more info about probiotics at our blog, click here.
Can I use your cultures to make soy yogurt?
Yes, although they do contain a slight amount of dry milk powder (to feed the bacteria). We are always looking for recipes for alternative "yogurts," so if you have any, send them to Moosletter@cheesemaking.com. We currently have one article with soy recipes at our blog- Soy Cheese with Louise Dutton.
Large Culture Packs
How do I decide whether to use the large packs or the small packs?>
If you are making your cheese in 2-4 gallon batches, we recommend using the small packs. The reason for this is the risk of contamination. Every time you open the large pack, you are exposing the bacteria to competing bacteria in the air. After only a few openings, your culture begins to lose strength and the balance of bacteria is compromised. Even if you are very careful with sanitation, the thawing and re-freezing and the moisture from the air will reduce the activity of the culture as well.
The large packs are economical if you are making large quantities of cheese (6-12 gallon batches of cheese). Partial packs will last 3-6 months or 8-12 uses before they become contaminated. We carry them mainly for the small scale commercial cheese makers and because they are Kosher.
How should we use the large packs?
You will use 1/2 teaspoon to inoculate about 6-12 gallons of milk. (If using raw milk, that can be reduced by 25-50%.) If your recipe calls for a small pack of culture, use 1/4 tsp. from the comparable large pack.
Are the large packs re-culturable?
No. These are direct set cultures. As with the small packs, you might be able to re-culture them once or twice, but the results will be unpredictable.
What are DCU's on the cover of the large pack cultures?
It stands for Danisco Culture Units. It's merely a measure of the activity of the cultures.
How do I know which lipase to use?
As a rule, you would use the milder one, Italase for Blue, Mozzarella, and Parmesan. You would use the sharper one, Capilase for Romano and Provolone because it contains an enzyme which produces stronger flavored cheese. Of course, it is always a question of taste.
It is an optional additive and many cheese makers do not use it at all. We recommend starting with the Italase and if you want more flavor, try the Capilase the next time.
There is more information
about lipase at our blog.
What is tartaric acid and is it the same as cream of tartar?
We use tartaric acid to provide the acid for thickening the cream in Mascarpone, instead of using live bacteria. It does not require refrigeration. Cream of tartar is a salt.
is used to impart a sour taste in foods.
lowers pH, helping to prevent spoilage from "bad" bacteria.
acts as a preservative after fermentation.
Why am I supposed to add calcium chloride to my store-bought milk?
Adding calcium chloride compensates for calcium loss during cold storage. Our calcium chloride is a 32% solution. It is always added to the milk right before adding the rennet. You usually add the same amount of calcium chloride to your milk as the amount of rennet.
We recommend using 1/4 tsp. calcium chloride with your milk if it is raw and 1/2 tsp. if it has been pasteurized. Dilute it in 1/4 cup of cool non-chlorinated water and add it when you begin heating your milk. Then, after adding your rennet, allow the milk to set 3-5 minutes longer than usual before cutting your curds.
I am not getting enough color when I use 2 drops of cheese coloring per gallon of milk, as you specify.
Color is very subjective. The intent here is to add a slight cream color to milk when the cow is not grazing on grass. If you are looking for an orange cheese, it will take lots more than that - up to 20-50 drops of cheese coloring.
Note: The color may darken slightly when the curds are completely drained.
Can I use carrot juice instead of cheese coloring?
You can use any substitute you want, but it will affect the flavor of your cheese. Our cheese coloring has been manufactured specifically for cheese making.