Monday, October 4, 2010

Homegrown Rennet

I call myself an obsessed home cheesemaker, and perhaps to prove my point I decided this last summer to try to grow my own rennet and use it to make my own cheese. A milk coagulating enzyme can be extracted from certain thistle flowers, including the cardoon thistle. I grew six of these thistles from seed to nearly four foot high plants in soil that has otherwise been unused between the sidewalk and the street. The cardoon is related to the artichoke and apparently you can eat the young flowers. I may try cooking a few, but my primary goal was to harvest the purple stamens in which the milk coagulating enzymes are found.

How do you extract the rennet from the thistle? A Google search for "Thistle Rennet" turns up pages that reference the book "The Encyclopedia of Country Living:
An Old Fashioned Recipe Book
" by Carla Emery. This book recommends the following:
Gather the thistle flowers when they have turned brown. If you see thistledown, the plant is over-mature. Get it right after the end of bloom and before the stage where down blows away. Air dry the flowers.

This confused me because everything I had read and heard on the subject indicated that the purple stamens were the part of the plant that held the rennet. Not wanting to waste my thistle or my expensive raw milk, I sent an email to cheesemaker Alyce Birchenough of Sweet Home Farm. Alyce was mentioned in a spring 2010 Culture Magazine article on thistle based rennet cheeses and she was kind enough to reply to my query with information she received when watching the cheesemaking procedure in Italy:

Cardoon (Cynara cardunculus) is commonly used in Spain and Portugal as a vegetal rennet to coagulate sheep milk cheese. The following notes were obtained at Corfilac in Ragusa, Sicily at Cheese Art 2006 at a hands on demonstration workshop.

The part of the cardoon used to coagulate milk for cheesemaking is the lavender stamens that appear when the plant is in bloom. The stamens may be plucked or cut away from the base with a knife. The stamens should be dried at room temperature for about 3 weeks with periodic stirring to prevent mold growth. The dried stamens will keep for 2 years.

In a mortar and pestle or a blender grind the cardoon stamens to a powder. Suggested use rate is 1 gram of dried flower per liter of milk. The ground stamen should be steeped in room temperature water at the rate of 1 gram stamen to 10 ml water. Steep the mixture for 30 minutes. Strain through a paper filter before use. Add to the ripened milk at 30 C or 86F. i.e. 100 ml solution for 10 liters of milk. Coagulation should occur in 30- 45 minutes. Fresh flowers may also be used and the usage may be slightly reduced since the activity is stronger when fresh. This coagulant is more proteolytic and will produce a softer cheese.Proceed with the make procedure as desired.

This information made a lot more sense to me, and it had precise measurements to follow. I was very excited and I decided to modify a Camembert recipe to use this rennet.

Thistle based rennet produces a bitter flavor if used with cow milk if the cheese is not eaten within a few days. This is because unlike traditional rennet enzymes, which only trim off the ends of the milk casin proteins, thistle rennet cleaves the casin proteins at many points. In cow milk this results in a bitter flavor, but not in goat or sheep milk. Therefore I was destined to make my first goat milk cheese.

I obtained two gallons of goat milk from a local goat farm called Terra Farma, and I used 1.5 gallons to make cardoon cheese. The remaining half gallon became fresh chevre, a recipe I in which had some confidence and therefore guaranteed me at least one good cheese from my first experiment with goat milk. The milk had a slight hint of the "barnyardy" flavor, which I associate with goat milk, but otherwise seemed very fresh.

I calculated that 1.5 gallons is about 7 liters of milk, and so should require about 7 grams of dried stamens according to the above research. I was using fresh stamens, so I reasoned I would not need as much, however since the stamens were fresh they contained more water, and therefore would weigh more than the equivalent dried amount. Furthermore my kitchen scale was not sensitive enough to accurately measure this small amount of thistle. I was reduced to guessing that the purple trimmings of two full thistles would be about 7 grams in weight, and would do the job. Apparently it was.

I ground up the stamens with a pestle and mortar, and mixed with 70 ml of boiled and cooled water. I allowed the mixture to steep for 30 minutes while my milk was culturing, then I filtered it through a coffee filter and used it as just as regular rennet.

I must mention that lack of sanitation of this process had me a little concerned. The thistles came in fresh from the garden where the local honey bees had just been busily rooting around in them searching for nectar. I was concerned about deactivating the enzyme and so I used no sanitizers on the thistles other than a rinse in tap water before cutting. A little bit of the local bacterial fauna is bound to get in one’s homemade cheese, and might impart a local flavor unique to the cheesemaker. If any of my cheeses were going to have a local flavor, this would be one.

I modified a Camembert recipe for use with this cheese, as I wanted something that would age quickly. I did not add mold spores to the cheese, as I would for Camembert, as I wanted any flavors derived from the rennet to not be overpowered. I understand that the proteolysis, or protein splitting properties of thistle rennet tends to create a runny cheese. This reminded me of the runny center of Camembert, which is why I choose it as my starting point.

To 1.5 gallons of goat milk warmed to 86F I added 4 ounces of frozen mesophilic culture and I allowed this to culture for 45 minutes. Then I added the 70 ml of rennet prepared as described above. 45 minutes later, I checked the milk to find it nicely coagulated. I was very pleased with myself. Until this point I strongly suspected that this was not going to work, and I was very excited this was not the case.

I cut the curd to 1 inch cubes, allowed them to heal for 10 minutes, then stirred gently for 20 more minutes, all while keeping the milk at 86F. After stirring I let the curds settle and mat, and then transferred to round molds on top of draining mats. As I would for Camembert, I did not press the cheese, but rather flipped the molds at regular intervals, allowing the curds to mat under their own weight.

After 24 hours of draining, I removed the molds. They cheeses started to barrel immediately. The sides bowed outward and the cheese could not hold its own shape now that the walls of the mold were no longer keeping it confined. I feared that I had not extracted enough whey from the curds during cooking. When I repeat this experiment, I will probably cut to smaller 1/2 inch cubes, or even smaller. To keep the cheeses from barreling too much I wrapped them with a strip of cheesecloth similar to the wrapping I had seen on traditional thistle cheeses in the spring issue of Culture Magazine. Apparently this is a traditional wrapping to keep the cheese whole as the proteolytic enzymes in the thistle rennet turn the center of the cheese very runny.

Since the cheeses seemed too moist I decided to let them dry for two days at room temperature. Then I moved them to my wine refrigerator turned aging cave. Normally I keep cheese in some sort of container in this wine refrigerator because its circulation fans tent to dry out the cheese. This time I waited a week before transferring them to containers, again because I felt the cheeses were too moist.

As I write this, the cheeses have been aging two weeks. One has dried out quite a bit more than I would like while the other one seems perfect except for a little bit of blue mold, which I wiped off with a mixture of vinegar and salt. I hope to age these for at least 6 weeks before trying them, but I will have to keep a closer eye on them from now on. Stay tuned for future updates.

Saturday, August 28, 2010

Culture Magazine

My first article has just been published in Culture Magazine's fall issue. Follow the link for the online version of the article.

Cheese-A-Topia Snapshots

I have been running around the American Cheese Society 2010 conference with my fancy camera having a blast. I just found time before breakfast on the last day to post some pictures. More to come...

Tuesday, May 11, 2010

Home Yogurt Making

Yogurt falls into the category of "dairy product," a category that also includes cheese, butter, crème fraiche, and kefir, among other things. While it is not cheese, it fits nicely into the discussion of home cheesemaking because making yogurt is identical to culturing cheese, and you get to skip all of those complicated (but fun!) chores like cutting curds, pressing, and aging.

Yogurt is simply milk which has been fermented by a cocktail of lactic bacteria. Yogurt cultures prefer temperatures near 115°F, much warmer than mesophilic cultures which prefer the 85-90°F range. There is some overlap in bacterial species between thermophilic cheese cultures and yogurt culture, and in a pinch you can use yogurt in place of thermophilic culture to make cheese, though the results will not be identical. Technical facts aside, what this simply means is that if you heat milk to 115°F, add some commercial yogurt with active cultures, and maintain the temperature for 12-16 hours you can turn 8 oz of yogurt into 2 quarts overnight.

In Alton Brown's Good Eats episode "Good Milk Gone Bad," Alton describes his mad scientist method of making yogurt which involves a clear container, a heating pad, and a trash can (he demonstrates this and other gadgets on a spot on David Letterman).
Being the devoted AB fan that I am, I constructed my own incubator using a flower vase, a heating pad, a towel, a digital thermometer and a light dimmer. It makes fantastic yogurt, but I have to admit it is not something I would recommend to someone who doesn't like tinkering with things like I do.

It occurred to me recently that rather than leading a prospective yogurt maker down the mad scientist path described above, you could keep milk warm overnight using the same method I have been using to culture cheese starter: Keeping a jar of inoculated milk in a picnic cooler filled with warm water. Basically you just warm the milk up to about 5°F higher than your target temperature and place in a picnic cooler with water of the same temperature. Over the course of incubation the temperature will drop slowly (the cooler does a pretty good job at maintaining heat), and for the majority of the time it will be in the right range.

So here is my recommended method for making yogurt at home, using easy to find items and no mad scientist contraptions. This method uses the microwave to heat the milk, which is my favorite method since it is easy to control and does not dirty a saucepan, but you can also heat the milk carefully on the stove if you like. If you can use more yogurt, mix up two jars instead of just one.

Homemade Yogurt


  • 1 clean one quart mason jar with lid (either standard canning lid or a white plastic freezer lid)
  • Dairy thermometer or kitchen thermometer in the 70-120°F range
  • Metal spoon that fits into jar and reaches to bottom
  • 1 small mixing bowl in which you can place the thermometer and spoon when you are not using them.
  • Picnic cooler large enough to hold the jar standing up


  • 4 ounces of yogurt labeled as containing active cultures (you can also use yogurt from a previous batch), or 1 packet of freeze dried yogurt starter
  • 1 quart of milk (2% or whole works well)
  • 1/2 cup of dried milk powder
  • Optional: 2 tablespoons of honey
  • Optional: 1 teaspoon vanilla


All equipment should be clean before starting.

Sterilize the jar and lid by filling the jar to the rim boiling water and putting on the lid. Being careful not to burn yourself, open the jar and sterilize the spoon placing it in jar for 2 minutes. Sterilize the mixing bowl and thermometer by filling the bowl with boiling water, running the water over the probe of the thermometer while filling the bowl. After 2 minutes, pour out the jar and the bowl. Set the spoon and thermometer in the bowl when you are not using them so they do not get contaminated.

Add milk to the jar until it is about 3/4 of the way full. Place jar in microwave and heat on high power for 1 minute, then remove, stir with spoon and check the temperature with thermometer. Return to microwave and heat again for 20 seconds, then stir and check temperature again. Repeat until the milk is 120°F. Place lid on jar.

Add dry milk and stir. Add the yogurt or starter and stir. Add the honey and vanilla, if using, for a sweeter yogurt.

Fill picnic cooler with hot water from the faucet. As you are filling, insert the thermometer in the cooler and adjust faucet until the water in the cooler is 120°F. Fill the cooler until the water level is equal to the height of the milk in the jar when the jar is inserted. Do not let the water come over the top of the jar or let the jar fall over.

Place cooler in a location where it will not be disturbed and insert the jar. Close the lid and let the yogurt incubate for 12 to 16 hours, until it is thick. Transfer the yogurt to the refrigerator and use within 2 to 3 weeks.

Thursday, March 18, 2010

Oregon Cheese Festival

I we be making the trip down to Central Point, Oregon this weekend to attend the Sixth Annual Oregon Cheese Festival. I'm looking forward to meeting all of the cheesemakers and trying avoid the cheese overload I experienced at the Wedge last October by carefully rationing the amount I sample.

If you see a guy walking around with a fancy camera and microphone trying to make it to every booth, come up and say hi!

Tuesday, March 9, 2010

"Without getting super technical, can you tell me how you make cheese?"

Recently my wife and I took our two year old daughter to our local wine shop for a Friday night tasting. No, we did not give our daughter wine, but we did bring some of my homemade blue cheese, which she loves, to keep her content while we tasted a Portuguese wine flight. Our server was intrigued and asked for a sample of my cheese, which I was more than happy to show off. After at least saying she liked the cheese, she asked me, "So without going into all of the details, tell me how do you make cheese?"

I tried, but I did not really do a good job. I gave too many details of the process that I know too well, and I am sure it was too much information for someone who merely knows that cheese comes from milk and just wants to know a little bit more. I disappointed myself because answering a question like this in a simple manner is something I should be able to do. So I resolved to do better next time and decided to write a "how you make cheese" elevator pitch that I can spew in 2 minutes or less. Here it goes:

"Making cheese is the process of turning liquid milk into a solid (or semi-solid) by trapping the milk solids and extracting a large portion of the water. Although there are as many variations on the method as there are types of cheese, in general bacteria and rennet are added and cause some of the proteins to coagulate into something that resembles gelatin. In fact, the proteins in gelatin trap liquid just like the milk proteins do. The coagulated milk is cut into pieces which are called curds. The curds weep a clear liquid, called whey, similar to firm yogurt weeping liquid to fill in the hole left by a spoon. Curds and whey are exactly what Miss Muffet ate while sitting on her tuffet. When heated or stirred the curds release more whey, then they are separated by pouring through cheesecloth or some sort of sieve. The curds are formed into the final shape of the cheese. Often the curds are pressed so they mat together, and hard cheeses are aged to improve their flavor. Aging can last from one month to two years.

"The same four ingredients of milk, bacteria, rennet, and salt are used to make cottage cheese, feta, mozzarella, Montery Jack, colby, cheddar, and gouda. The only difference is how the cheesemaker treats the curds during cheesemaking."

How was that?

Sunday, February 21, 2010

Sunset on Home Cheesemaking

In the February edition of Sunset Magazine I was delighted to see an article on making your own cheese at home. They obtained recipes from two established artisan cheesemakers and presented Cowgirl Creamery's Fromage Blanc and Bellwether Farms' Ricotta.

I was extremely excited to see a mainstream magazine touch on the home cheesemaking phenomenon. I was even more excited that they were hosting a contest for readers to create recipes using these cheeses, with a prize of tickets to California's Artisan Cheese Festival. I have discovered that I love to create recipes from scratch, it really gets the mad scientist in me going.

I entered a cheese desert, in the shape of a cocktail, turning the Cowgirl Creamery's Fromage Blanc into a "Sweet Cowgirl Cheesecake Cocktail."

You can download my Cheese Cocktail recipe here. If you make it let me know what you think. I thought it was a pretty good use of Fromage Blanc, which was one of the easiest cheeses I have attempted.

I also tried to make a savory dish with the ricotta by baking it whole. Sadly it unexpectedly burned in the oven. I will have to work a bit longer on getting that one right.

Monday, January 25, 2010

Rennet from a Thistle?

I met Jon Clark at a recent cheese class where he was a student. Jon is currently teaching English in Hungary. Though he is really interested in making cheese, he does not have the luxury of being able to order ingredients over the internet and have them arrive in a timely or economical fashion.

We discussed that it is possible to harvest your own rennet, and I forwarded him a link to another obsessed cheesemaker, David B. Fankhauser. Dr. Fankhauser shows his attempt to create his own rennet from the stomach of a suckling kid (the goat kind). I thought if Jon were really desperate, this was something that he could try. If seeing where your food comes from does not disturb you, check it out here.

Jon replied and told me he had coincidentally just seen that very page in a recent posting to the blog Serious Eats. In this entry Jake Lahne discusses the use of the Cardoon Thistle as a cheesemaking coagulant.

I have read in American Farmstead Cheese that thistle was used in historic cheesemaking when animal rennet was not available or not desired. Jewish cheesemakers used thistle to create a kosher cheese (avoiding mixing meat and milk). Some cheeses are still made today using this process: Torta la Serena, Torta del Casar, and Serra da Estrela are examples.

I am very curious about trying to use Cardoon as a coagulant. My favorite seed company carries it, so I will try planting some this year. Stay tuned for results this summer/fall.

Saturday, January 23, 2010

Making Feta at Home

For my first live demonstration I chose to make Feta cheese since it was relatively easy and a perfect rennet coagulated cheese for the beginning cheesemaker to tackle. I wanted to discuss the results from using live starter culture instead of direct acidification, show what a clean break looks like, and walk through the process of cutting and cooking curds. I felt the demonstration went really well, and strangely no one complained about my long winded food science talk of enzymes and proteins. Blogger "Food and Books and Stuff" posted a lovely review on her blog.

I adapted a Feta recipe I received in the class "A Practical Introduction to Cheesemaking" which I took at Oregon State University. I added an introduction that covered home cheesemaking equipment and sanitation, edited it until it fit on the front and back of a single sheet of paper, and used the results as a handout. You can download it from the Joy of Home Cheesemaking site for your own first attempt at rennet coagulated cheese.

Due to the leftovers from the class and the trial makes I did in preparation, my family has a lot of Feta to consume. Weekends are my turn to make dinner, so I am making Spanakopita.

Saturday, January 16, 2010

The Homebrew Exchange

The owners of The Homebrew Exchange let me know a little while back that they were having an open house today, and the thought never occurred to me that it would be worth re-posting the invite. Talk about late notice, I apologize.

Anyway, if you see this post today, and happen to be in the neighborhood, drop in and say hi. I will be there with some sample feta cheese that I made for my demonstration next Wednesday. The owners of The Homebrew Exchange are super nice and they are showing a real commitment to carrying cheesemaking supplies. I was really excited to have another place in town to send people who need supplies.

The Homebrew Exchange is located at 1907 N Kilpatrick St, Portland, OR 97217, and the open house starts at 4 p.m. Here is a direct link to the announcement on their web site.

Tuesday, January 5, 2010

DIY Cheesemakers in Portland

Portland has a great food community, including enough cheese enthusiasts to warrant a loosely formed organization of home cheesemakers called the DIY Cheesemakers. This group has been meeting at a great local cheese shop called Foster and Dobbs Authentic Foods.

I attended my first meeting last November and met Gayle Starbuck, who led a class on making fresh cheeses with direct set cultures. She and I talked after the class and I agreed to help set up an email list to help communicate between the meeting participants. That list now lives as a Google group, which can be found at

I also talked to Luan Schooler after the same DIY meeting. Luan is one of the owners of Foster and Dobbs, and from what I can tell she started hosting the DIY meetings in 2008. I offered to do a cheesemaking demonstration. After an exchange of emails, I am now demonstrating making Feta on January 20th, 2010. I am very excited.

This weekend I have plans to visit a local goat farm to acquire some fresh raw milk and do a trial cheesemaking run at home. If the results are good, they will show up at the meeting on the 20th. I am also going to do a practice run with store bought cow milk to hopefully show the difference between the two milk sources. The demo will done with store bought milk, as that is what most people will be using in their own kitchens.

So if you are in the Portland area, come join the fun. See the details at