Making Yogurt

The SCD Way

“One of the remarkable qualities of milk is that it invites its own preservation. It can spontaneously foster a particular group of microbes that convert its sugar into acid, and thereby preserve it for some time from spoiling or harboring disease.”

H. McGee [1]

I grew up in Bulgaria, a country where yogurt is literally around you everywhere and all the time (I even remember jokes that the best way to keep fit is to have sex and eat only yogurt). I, however, was not a big fan of yogurt and never really had much of it. I wonder now that I have learned more about the gut, if that was due to residual lactose still present in the yogurt. I had seen people around me make yogurt at home without any special equipment, and I had friends who at the end of summer vacation, after visiting their grandparents or relatives living in small villages, would bring home special yogurts such as goat milk yogurt. Mostly though, everyone would buy a couple of yogurt containers from the store to last them a day or two. After 1989 when a lot of Bulgarian people, including my family, hopped on a plane to the nearest or not so nearest established democracy, the disappointment in the yogurts in these new homelands led to a few people actually bringing Bulgarian yogurt with them there, and using it to keep a home production going. But despite being around this culture of yogurt production I had never attempted to make one until I realized the importance of probiotic foods in healing the gut. I will dive into a few basics of why and how yogurt can help with gut health, but you can skip directly to how to make yogurt, or if you want to see a few cool snack ideas for kids and adults alike click here: Berry Yogurt, Greek yogurt, Raita & Tsatsiki, and Ayran/Doogh.

So what is all this fuss about probiotic foods? Well, the answer to this is complex and multifaceted, but let’s start with one fundamental part to it: consuming certain probiotics can inhibit the growth of pathogens in the gut. This is important since it is believed that gut dysbiosis is linked to disease: “There is growing evidence that dysbiosis of the gut microbiota is associated with the pathogenesis of both intestinal and extra-intestinal disorders.”[2] What that means is that when the bacteria living symbiotically with us, found on and in our bodies, our gut in this case specifically, are out of equilibrium we can become sick. It has been found that consuming certain probiotics can help fix this state of dysbiosis [3].

In the Specific Carbohydrate Diet (SCD) [4], whose aim is to heal the gut, the suggested way to increase probiotic consumption is to eat yogurt. The trick to SCD yogurt is to ferment it for 24 hrs in order to make sure that the fermenting bacteria, known as Lactic Acid Bacteria (LAB), consume all the sugar found in milk. This sugar is called lactose and the bacteria turn it into lactic acid during fermentation. It is very important to make sure that there is no lactose left over at the end of the fermentation. The idea is that in people with damaged guts the enzyme, lactase, that breaks down lactose, is not available to do so, and the lactose stays in the gut becoming food for pathogenic bacteria there. In comparison to the 24 hour fermentation in SCD yogurt, most commercially produced yogurt is fermented in about 4-6 hours, and thus most likely has lactose present in it.

Before making home made yogurt there a few basics to settle:

  • The milk used.
  • The fermenting culture.
  • Upkeep of the incubation environment.

The milk and the fermenting culture each deserve a post of their own or more, which is to follow. For now I will make a quick suggestion that it is best to use organic and if possible also A2 (instead of A1) milk. I am also assuming it is cow’s milk just because in my experience it is not easy to source any other kind. In terms of the bacterial culture currently the FDA requires two bacterial species to be present in yogurt (Lactobacillus Delbrueackii subsp. Bulgaricus, and Streptococcus Thermophilus) [5], but traditional or heirloom yogurts harbour many different species. So when buying yogurt from the store it will have those two bacterial species, with some manufacturers adding a few others they believe beneficial to the two required by law. Here, to simplify things, as a starter, I used store bought yogurt that I liked, which contained live cultures.

Making Yogurt

Step 1: To heat or not to heat the milk. Most recipes for making yogurt start with the instruction to heat the milk to almost boiling point 175-185oF (80-85oC). This I believed was to ensure that bacteria found in the milk would be killed off, in order not to compete with the LAB introduced at the start of incubation. If using raw milk that would be the case, but in pasteurized milk I thought, surely that shouldn’t be an issue. So, I found out the second and more important reason for this when using pasteurized milk at least, is actually to improve the yogurt’s consistency by denaturing one of the milk proteins (yes you guessed it, it’s the lactoglobulin – just kidding, it’s the first I heard of it serving that purpose too). This I found to be important information, because it can save us time should we forego to heat the milk. I have generally been skipping this step with pasteurized milk when I am in a hurry, which is almost always. It is true that the yogurt is not as thick, but not enough to bother me, and the saved time is a benefit in my books. BTW, when a protein gets denatured, it looses its original shape (in this case lactoglobulin looses its original shape through the application of heat).

To do the heating properly I got a digital thermometer, which I ended up breaking after only a few uses, as you will see further down, but using the thermometer for the first few times gave me a feel for what milk looks like at 175oF(80oC) temperature, so that I avoid fully boiling it without a thermometer. Perhaps borrowing one could be a good option for the first few times of heating the milk.

Once the milk has been heated it needs to cool down, so that when the bacterial culture gets added it doesn’t get killed by the high temperature. Some people suggest to place the milk in a cold water bath to have that happen faster. Preparing a water bath seemed like it would be work I can do without so to cool it down I simlply waited for a few hours. I usually add the starter culture when the milk is anywhere in between about 110-104oF(~45-40oC). It is a good idea to have the starter culture be at room temperature too.

Step 2: Adding the culture. To start with it is easiest to buy store bought yogurt and use it to culture the milk. The yogurt used should be plain, have no additives, and contain live cultures. The starter I used contained the following cultures: L. Acidophilus, L. Bulgaricus, S. Thermophilus, and B. Bifidum (a side note in SCD, Bifidobacteria are not recommmended, because they are most numerous in the human gut during infancy and the SCD author, Elaine Gottschall, suggests we should not ingest much of them as adults. I still have to investigate this in detail as I have also heard of their beneficial qualities). Most recipes instruct to use 1/4 cup of yogurt starter per quart (liter) of milk. I also read that less is more when it comes to cultures, and to use just a tablespoon per quart (liter) [6,7]. When comparing the two versions of yogurt, I clearly prefer the one made with just a tablespoon per quart. Also it should be noted that the cultures used from commercially produced yogurts can only propagate for a few generations. This means that every 3-4 times you make yogurt you will not be able to culture the milk using your previous batch, which is known as back-slopping, and will have to purchase a new container of store bought yogurt. Heirloom cultures (which have diverse and usually undefined bacteria) on the other hand can go on indefinitely.

Step 3: Setting up the incubation. This step includes the length of time and temperature kept while the bacteria works to turn milk into yogurt. The bacteria in yogurt is thermophilic, which means it thrives best at 86-114oF(30-45oC). There are different ways to upkeep a warm environment, such as a yogurt maker or an oven light. However, since SCD requires a 24hr fermentation, it gets a bit trickier. The temperature maintained, has to be at the lower end around 104oF, to make sure the bacteria work slower and consume all the lactose. I found only one yogurt maker on the market that had the desired specs. Since it was my first time making yogurt I decided to go ahead with it. I also tried fermenting in a cooler.

For the cooler fermentation I prepared the milk and culture in two mason jars, and then filled the cooler with warm water at 110oF(45oC). I placed the jars in it and closed the lid. I checked the water temperature after 6 hrs and it had fallen to about 105oF. So I replaced some of the water with warmer water to increase the temperature again. I left it overnight and measured the temperature again in the morning, when it had dropped to 95oF. So I wasn’t sure how well the bacteria had worked with this oscillation in temperatures. Also at this point while I was measuring the temperature my digital thermometer fell in the water, it made a long beeping sound, stopped working, and wouldn’t restart even after I waited long enough for it to dry. The yogurt tasted very nice, however, as I wrote I am pretty sure that it had residual lactose, as it affected both me and my son, making him overly emotional.

After the proper 24 hr fermentation is complete, it is good to place the yogurt in the fridge for 8hrs or more. This really helps settle it and give it a much nicer texture and flavor. In fact the longer it sits in the fridge the better it tastes (overnight, or even longer is best).

Ok, so after settling on the yogurt maker method for now, and getting my yogurt going, it was time to let the creativity start. There are so many cool things that can be made with yogurt. Below I am showing just a few options, that I find fun to make and delicious to eat.

Berry Yogurt

This is the easiest and healthiest way to make flavored yogurt and it is very much enjoyed by my son.

Mix honey in the yogurt (to taste) and add the berries – raspberries, blackberries, and strawberries (make sure to cut the strawberries into bite size pieces for extra flavor). Let sit in the fridge overnight or longer to get the berries to release their yumminess.

Greek Yogurt

I like Greek yogurt for its more viscous and thick consistency. To make it all I had to do is to line a colander with a cheese cloth, place the yogurt on top to drain and let sit for a few hours or more depending on the desired thickness.

The end result is a separation of the curds and the whey. Technically, this is not the same whey as the one Little Miss Muffet was eating which is called sweet whey. The whey here is termed acid or sour whey, since it is already cultured, and disposing of it is interestingly becoming an environmental concern in commercial production of Greek yogurt which has increased recently. The whey collected in our case, however, does not have to be an environmental concern and you can either drink it with some honey for a probiotic drink or use it to (lacto)ferment veggies, a future post will be devoted to that subject. I should point out that when we are consuming the same amount of Greek yogurt as regular yogurt we are eating more casein, since its concentration is higher in Greek yogurt.

Raita & Tsatsiki

Naturally, with my Greek yogurt I wanted to make some Tsatsiki. I followed a recipe from Wild Fermentation [6] and alongside it there was a recipe for a similar dish called Raita used in Indian cooking. I wanted to compare both variations.

I actually used regular yogurt for the Raita since I wanted to use it as a condiment, but that change is not necessary. The common ingredients in both dishes are grated cucumber, a few pressed garlic cloves, and salt. Where they differ is that the Tsatsiki takes crushed pecans/walnuts, olive oil, lemon juice, chopped up parsley, dill, and mint leaves, while to the Raita, cumin and chopped up cilantro is added.

Ayran/Doogh

The last thing I wanted to make for this post is another recipe I noticed in the Wild Fermentation book, this was for an Iranian beverage called doogh. Something was drawing me to it, and I realized I actually grew up around a similar beverage called ayran. There are lengthy discussions on the internet on all the variations of how this beverage can be made, and where it originates from. Here, I just have a simple version, that is fun and easy to make.

All I did was whisk gently 2 cups of yogurt to create a smooth consistency, afterward I added about a cup of sparkling water. Before serving sprinkling some salt on top makes the bubbliness pop even more. You can add dried mint to it too for another variation.

REFERENCES

1. On Food And Cooking, The Science And Lore Of The Kitchen,Completely Revised and Updated, Harold McGee, 2004, https://www.curiouscook.com/site/about-harold-mcgee.html/.

2. Dysbiosis of the gut microbiota in disease, S. Carding et al., Microb Ecol Health Dis. 2015; 26: 10.3402/mehd.v26.26191

3. Understanding the mechanisms by which probiotics inhibit gastrointestinal pathogens, S. Corr et al., Adv Food Nutr Res. 2009;56:1-15

4. Breaking The Vicious Cycle, Intestinal Health Through Diet, Elaine Gottschal B.A., M.Sc., http://www.breakingtheviciouscycle.info/home/

5. CFR – Code of Federal Regulations Title 21, Part 131, Sec. 131.200, accessed Apr. 29, 2020

6. Wild Fermentation, The Flavor, Nutrition, and Craft of Live-Culture Foods, 2nd Edition, Sandor Ellix Katz, 2016, wildfermentation.com

7. Joy Of Cooking, 1997 Edition, Irma S. Rombauer, www.thejoykitchen.com