GAPS Basics: How to make GAPS yogurt
You may already make yogurt when you come to GAPS or it may be a kitchen activity that sounds overwhelming and complex. In either case GAPS yogurt may be a new process that, while complex at first, will become a very familiar part of your food routine very quickly.
Do you see the beautiful cream line on this raw milk yogurt?
First we should talk about why you should consume yogurt. Fermented milk products have been consumed as long as humans have consumed dairy from domesticated animals. Proper fermentation helps to turn a highly perishable products, fresh sweet milk, into a shelf stable product. The simplest way to do this is to simply allow raw milk to clabber, that is sit out and ferment with it’s own innate bacteria. This is a simple process requiring no preparation but runs the risk of fermenting the wrong bacteria and ending up with something putrid, not tasty. So it was discovered that if you add some of the previously successfully clabbered milk it is more likely to end up tasting the same/good. This gives the preferred bacteria a head start and lets them outgrow the other, less desirable bacteria that may be present. Over time various ways were discovered to make fermenting come out in more predictable and desirable ways. This involve adding something to the milk and controlling it’s environment in different ways. Kefir and yogurt are two of those cultures but there are others. The basic formula is the same, you add microbes of some kind to fresh milk and allow it to proliferate in that milk. This consumes the lactose in the milk and transforms it into a tasty more shelf stable product.
This traditional way of fermenting milk has served humans since before recorded history. Furthermore humans have consumed fermented foods in every section of the planet and our gut depends on the influx of these friendly bacteria on a daily basis in order to maintain health. Yogurt is simply one of those fermented foods, however, there is a challenge if you have a damaged gut. Digesting the lactose in these foods can be difficult for your gut. While some dairy products (like aged cheese) have all of the lactose consumed others (like traditional yogurt) still maintain a significant amount of lactose that can cause discomfort and damage.
The GAPS diet comes from the Specific Carbohydrate Diet (SCD). Elaine Gottschall, who popularized this diet, tested and discovered that at 24 hours nearly all of the lactose has been consumed by the bacteria in yogurt culture. Jordan Rubin discovered that at 30 hours the lactose is completely gone but that means that all of the food for the beneficial bacteria is gone and the colony will quickly collapse and die without any residual food. After GAPS yogurt is fully fermented it still contains the sugar galactose. This is a monosacharide that must be converted in the liver to glucose in order to be used by the body and so shouldn’t be consumed in unlimited quantities, esp by those with health problems. Elaine placed a daily limit at 3 cups of yogurt for adults and 2 cups for children. That seems like a prudent rule to follow for those of us on GAPS as well.
So for GAPS yogurt the recommendation is to ferment it for 24 to 29 hours. This will eliminate enough of the lactose to prevent digestive problems and yet leave a trace behind for keeping the colony of beneficial bacteria alive until it is consumed. In just a cup of properly prepared GAPS Yoghurt (236ml) you’ll get 708 Billion beneficial bacteria. (source). That is a lot of beneficial bacteria. Bio-Kult Probiotic, for example, has just 2 billion cfu (cell forming units).
Since it takes 24-29 hours to make this yogurt it may be tempting to make up a whole bunch at once and then dole it out over time. This isn’t such a great idea however. The beneficial bacteria in yogurt don’t last very long and after 2 weeks have nearly all died. You can only expect GAPS yogurt to last 3-4 weeks in the fridge at the most but past 2 weeks it isn’t really a probiotic food, just a lactose free dairy food. (source) There is some speculation that there is benefit from ingesting dead bacteria but that hasn’t been proven at this point. It is known that dead microbes are the main source of bulk in the stool and assist elimination so if nothing else dead yogurt should help keep you more regular. Of course dairy protein can be constipating so perhaps it is just be a wash.
Ok so how is this wonderful yogurt made? you ask.
To make yogurt you need:
- Milk, either raw or pasteurized from cows, goats or sheep.
- A way to heat the milk to 180 degrees and a thermometer to determine the temperature of the milk.
- Some sort of culture to get it started in the right direction.
- A way to keep it at the right temperature for at least 24 hours.
I’l talk about each of these individually.
Selecting milk for fermenting
The milk that you use can be raw or pasteurized. For this process we are only talking about actual milk. Making yogurt from nut milks or the like is a somewhat different process and needs it’s own post. If you have read the GAPS book you know that the most nutritious milk will be from animals eating their species appropriate food. For cows and sheep this means exclusively grassfed. Goats are browsers and can’t be exclusively grassfed although in the right conditions they can do well without grains. When trying to decide what kind of milk to get, raw is always the best choice if you can find it. The next best milk to look for is grassfed, pasteurized but not homogenized. This milk will have cream floating on the top. If you can’t get non-homogonized milk look for skim milk without added milk solids and heavy cream and combine them to make your own non-homogonized whole milk. Do not ever use ultra pasteurized milk. This is also called UHT milk. This milk will not make yogurt and is not healthy for anyone to consume even if it is organic. If you can’t find grassfed milk then choose organic milk. These cows have been fed grains and will not produce as nutritious a milk as grassfed cows but at least the milk won’t have rGBH in it or traces of pesticides or antibiotics. If you truly can’t afford any of these options then conventional milk will also make GAPS yogurt. Just be certain that it is not UHT milk.
Heating your milk
If your milk it is raw you need to make a choice. Do you want to leave it raw or pasteurize it. Some (like my family) like leaving it raw to get the benefits of raw milk in a lactose free, probiotic food. This tends to result in a thinner yogurt that sometimes ferments wrong because the innate bacteria in the milk out competes the yogurt culture. Others prefer the thicker quality and predictability of yogurt made from cooked milk. They also reason that they don’t want anything competing with the proven beneficial strains of the yogurt culture and so they want to start with a clean slate by killing off the bacteria found in raw milk. They know that the milk they are getting from their farmer is of superior quality to what is available in the grocery store and so it still is the best choice for consumption even if it will no longer be raw. Both arguments have merit and it will be up to you to decide which method you will pursue for your raw milk. If you choose to cook the milk proceed as for pasteurized milk.
About pasteurized milk there is no debate. It is necessary to heat all previously pasteurized milk to 180 before making it into yogurt. This untangles the proteins and destroys any microbes that may have contaminated it since it was first processed. I do this heating on the stove top in a stainless steel pan. You want the pan to be somewhat bigger than what will just hold the milk that you are heating since it will expand somewhat when heated. Do not boil the milk. You just want to heat it to 180 and then let it cool. You need a thermometer to keep track of the temperature if you are following this method. I use one like this Pocket Thermometer. Do not let it go over 180. It works best to heat it on medium on the stove. This takes longer but you are far less likely to overshoot your goal and boil the milk. Try to occupy yourself in the kitchen while doing this or you will discover that an unwatched pot does indeed boil when you least expect it. After heating it to 180 you then need to cool the milk to 110 or so. You can do this by just leaving it in the pot for a while or you can put it into a container that you set in a sink full of ice or cool water. I have been known to pour it into the qt jars I intend to incubate it in and set them into ice water to cool it off faster. Again keep track or you may end up overshooting your goal. If you are planning to leave your milk raw you can gently heat it to 110 or follow my lazy method and just leave it cold and allow the incubation method to bring it up to temperature.
Selecting a culture
There are many different approaches to this as well. My family uses Yogurt Starter 2 from Custom Probiotics. This has 5 strains of beneficial bacteria and no fillers. One jar lasted us about 18 months making 1-2 gallons of yogurt a week. We did find that different sources of milk needed more or less starter to come out the best but that wasn’t really a hardship. We also have used 11-strain probiotic powder also from Custom Probiotics. This doesn’t have as good a taste but these particular strains are very beneficial for people who have difficulties with oxalates like myself and one daughter. Another common yogurt starter is made by Yogourmet Yogourmet Freeze Dried Yogurt Starter. This is available at many health food stores and some mainstream grocery stores as well. It does have some ingredients not allowed on GAPS/SCD however it was the opinion of Elaine Gottschall that the small amount of illegal ingredients would be consumed in the fermenting process and not cause a problem. This was the starter that I used most of the time while my family was following SCD in 2006. One more even more widely available source of starter is to simply purchase a plain yogurt without additives. It is important to look at the ingredients list and avoid yogurts with added flavors, sweeteners, starch or pectin. Also make sure that it says somewhere on the packaging that it contains live cultures.
What about just using the yogurt you have already made as a starter? Unlike kefir, yogurt bacteria aren’t robust and are susceptible to becoming contaminated by other bacteria. If you are making raw milk yogurt you can use some of the previously made yogurt for one more generation. That is that if you use a starter to make yogurt, you can safely make yogurt using the resulting yogurt as a starter once. You must do this within 2 weeks of making the original yogurt or it will be unlikely that you will have enough living culture to start the next batch. If you are making yogurt with pasteurized milk you can safely culture for another 3 generations. That is after making the original yogurt you can then use that yogurt (within 2 weeks) to make another batch, and use that resulting yogurt to make another batch and then one more time use the resulting yogurt to make a batch. It is possible that these yogurts will go on for more generations but the more times you do it the greater the chance that your culture will be corrupted and you will end up with a putrid result instead of yogurt. I find that my raw milk is far too expensive a commodity and the fact that it takes 24 hours to make one batch is too much time and effort to be risking that it won’t come out good nearly all of the time. I personally use a fresh starter each and every time to minimize the risk.
Incubating the Yogurt
This is probably the trickiest part of making yogurt. You must find a way to keep the milk warmer than 95 and cooler than 115 for 24 hours. This is a rather narrow range of temperatures. If it gets too hot, even for a minute, the culture will be killed and your yogurt will be ruined. If it gets too cold it will slow down the fermentation or even stop it and you will be left with a product that still contains too much lactose for someone on GAPS. Traditionally yogurt is only cultured for 4-6 hours and so methods that involve insulating the warm milk are often employed for this type of yogurt. Many people put it into a thermos or wrap it in a wool blanket. There is also a crock pot method that is very popular right now online. Each of these methods will only keep the milk warm for 4-8 hours and will be insufficient for our purposes. In order to keep the yogurt warm enough for 24 hours you will need an outside source of heat.
I have hesitated to write this blog post in part because I feel like I am cheating when I make yogurt. I use an Excalibur 9 Tray Dehydrator to make my yogurt. It is extremely simple to make yogurt in this machine. It has a temperature setting and enough room for 9 half gallon jars so I could easily make 4.5 gallons of yogurt at one time if I wanted to.
I also have used jelly jars like these or these to ferment yogurt in individual serving sizes. My children love having their own individual servings of yogurt and these are very easy to pack for eating away from home.
I have found that when fermenting raw yogurt, setting the Excalibur at the recommended 115 is too hot and ruins the yogurt. However, a setting of 95 turns out perfect yogurt every time. Since I rarely make yogurt with pasteurized milk I am not sure if that kind of milk does better at a slightly higher temperature. Perhaps someone can let us know in the comments if you have experience with making yogurt from pasteurized milk in this dehydrator and what temperature you use. With this machine I simply mix the culture into my cold milk and place it into the dehydrator set to 95 degrees . 25 hours later I take out finished yogurt and put it into the fridge. I give it an extra hour because I start with cold milk and want to give it time to get up to temperature.
I use my dehydrator for lots of things in addition to making yogurt and if you could possibly afford one I highly recommend that you invest in it. I purchased one without a timer and haven’t ever regretted that choice. I will have to do another blog post about all of the things that I have made in this machine.
If this dehydrator is not in your budget at this time there are other options. Yogurt makers are one option but they tend to have a problem. They get too hot when you run them for 24 hours straight. When I did SCD I used a Salton 1-Quart Yogurt Maker. It is my understanding that this is no longer being manufactured. To make it work without getting too hot I used a 1 qt canning jar in it and left the lid off. It was important with this kind of a maker that my milk was heated to 110 when it put it in or it spoiled because it didn’t come up to temp fast enough (I assume). I suspect that the Euro Cuisine 2qt Yogurt Maker would work in a similar fashion since it appears to be the same basic design but I have not tried it. If you already own a yogurt maker and are wondering if it will work to make GAPS yogurt I advise that you do a test run with just water in it and then take the temperature at the end of a full 24 hours. If it is above 115 it will kill the culture and ruin your yogurt. Some people have installed dimmer switches into the cord of yogurt makers in order to lower the temperature and have a successful result. You may also find as I did that removing a lid or some other modification will be enough to get the desired temperature range.
Another option is to replace the light bulb in your oven with a 60 watt light bulb and leave the light on and the yogurt in your oven for 24 hours. This should keep the interior the correct temperature. Some use a clip on lamp with a 60 watt light bulb that they run into the oven for this purpose. One obvious drawback to this arrangement is that you can’t use your oven for 24 hours. One advantage is that this method will accommodate a variety of jar sizes, like the dehydrator. Again, I recommend that you do a practice run with water before trying it with expensive raw milk to be sure that you have all of the details worked out. Some need to prop their oven door open to keep it from getting too hot with this method. Also think through how you will prevent someone from turning on your oven while your yogurt is in there incubating. There have been many stories told of people whose yogurt was cooked when they or another member of their household began to preheat the oven without looking inside of it first.
Some other do it yourself methods include using a cooler filled with hot water, wrapping the jars of milk in a heating pad, rigging up a foil lined box containing a lamp with a 60 watt light bulb integrated into it, and turning on and off a crock pot to maintain the appropriate temperature. Each of these methods will take some trial and error to get your liquid to maintain the appropriate temperature for the entire 24 hours but each has been used by resourceful people who want yogurt and don’t have the funds for an expensive apparatus to make it. I have no doubt that Google will reveal even more methods than I have mentioned here. I will recommend googling both SCD yogurt and GAPS yogurt to find the most results.
Once you have made your yogurt you may look at it and think that it doesn’t look very thick. It will come out the best if you put it into the refrigerator right away without shaking or stirring and allow it to chill for at least 6 hours before digging into it. This allows it to set up and get thicker. Raw milk and goats milk yogurts will be thinner than pasteurized cows milk but should still be thicker than unfermented milk. Different culture starters will also make for a thinner or thicker result. Do not be tempted to add powdered milk to your yogurt to make it thicker. Powdered milk has damaged proteins and is not healthy for anyone to consume. It also will raise the lactose level of the product and the result at the end of 24 hours will be yogurt with quite a bit of lactose remaining. If you really want a thicker product you can add gelatin when you add the yogurt culture. I have used Bernard Jensen Products – 100% Pure Gelatin. It may take some trial and error to find the thickness that you like best. You can also drip your finished yogurt through some cheesecloth to remove the whey and achieve a thicker product more like greek yogurt. Use your own judgement for how thick you want the results to be.
How to make GAPS Yogurt
1. (optional) Heat 1 qt of milk to 180
2. (optional) Cool milk to 110 or warm raw milk to 110
3. Mix in 1/4 cup of yogurt or starter culture (use package directions to know how much to use)
4. Place in dehydrator, yogurt maker, or other incubator for 24 to 29 hours
5. Refrigerate for at least 6 hours.
6. Enjoy, add flavors and sweeteners at this point if desired.
Once you have figured out how to make GAPS yogurt the process is fairly simple and straight forward. It is just collecting the culture and figuring out how to keep it warm that can be complicated. Once those questions are resolved you will find that it takes very little of your food prep time each week to make fresh yogurt.
Have you been making GAPS yogurt? Do you still have any questions about how to do it? Do you have an incubation method that I haven’t covered? What is your favorite starter? Please share the answers to these questions in the comments section for this post.
Please read these posts to learn what changes I have made in my yogurt fermenting
The Great Yogurt Experiment
The Great Yogurt Experiment after One Week
The Great Yogurt Experiment Conclusion