Yogurt making with the DigiQ II
Yogurt making is an age old process used to preserve milk and the first step in the production of some cheeses. The practice originated in Eastern Europe and Western Asia. Today yogurt is produced commercially worldwide. The production of yogurt is a simple process involving addition of L. bulgaricus and S. thermophilis to clean warm milk and then holding at the temperature between 108 and 112 degrees Fahrenheit. Accurate temperature control is needed to insure yogurt making success.
There is a large selection of home yogurt makers on the market. All should work well but most yogurt making appliances have very limited batch sizes. Some people have had success using insulated boxes, household ovens, and even the stovetop. All these methods will work as long as you can maintain the temperature between 108 and 112f. With the DigiQII and a Power Raptor controlling the temperature becomes a snap.
The focus here is to explain how to use the DigiQII temperature controller to control your electric appliance accurately. The DigiQII is a very versatile temperature control. Originally the DigiQII was linked to a twelve volt fan and used to control a charcoal fire. It can control power to any twelve volt fan or appliance. Coupling the DigiQII with the proper “Power Raptor” switching relay it can control any common household kitchen appliance. With the DigiQII and a Power Raptor the crock pot becomes a large capacity yogurt maker.
The set up is very easy. Plug the fan terminal on the DigiQII into the power raptor. Plug the crock pot or other appliance into the power raptor. Connect both the DigiQII and the Power Raptor into appropriate electrical wall outlet. The pit temperature probe is placed into the crock pot.
We use the longer meat probe that comes with the DigiQII only because the metal sleeve is longer on it. Make sure the tip of the probe is not touching the crock pot. If the probe tip is in contact with the inside of the pot you will likely be measuring the temperature of the pot and not the milk. Turn the crock pot on high and set the temperature control to over 165 degrees.
Pour the milk into the crock pot. I like to use a fresh sealed bottle of milk. You can use any type of milk you like.
As it is in all home cooking and canning processes, cleanliness is important to this process. In yogurt making cleanliness is especially important to prevent the growth of unfavorable bacteria. Milk should be heated to over 165f for ten minutes at the beginning of the process. This heating will kill any disease causing bacteria or mold spores that might be present in the milk. All equipment that comes in contact also needs to be clean. I like to put everything in the dishwasher and plan my yogurt making at the end of the cycle. Washing everything on the hot cycle assures that all equipment is sanitary. A large pot could be used to boil the equipment. Some folks claim that just a good soap and water hand washing of the equipment is all that is needed. In any case sanitary technique is important.
Chilling the milk quickly to the inoculation temperature minimizes the opportunity for other non-favorable bacteria to enter the process. Yogurt cultures will grow between the temperatures of about 100 and 130f but they thrive when the temperature is between 108 and 112f. Above this temperature the culture will slow reproduction dramatically or will be killed completely. Below this temperature range the growth will slow dramatically or the culture will become dormant. Keep this in mind when you add the culture to the milk. Temperature control here is very important.
Active yogurt cultures can be acquired in several different ways. Many people use a commercial yogurt from the grocery store and others use yogurt from a previous batch of homemade yogurt. If you use the commercial yogurt I prefer to use plain avoiding the sugars and other additives that might be in flavored yogurt. Packets of yogurt cultures can be purchased from most health food stores. There are pros and cons with any of these methods but success can be achieved with all. The most important thing is to be sure that the culture you use is fresh. Scoop out one cup of milk after it has cooled to well below 130 degrees. Add either the contents of the packet, a few spoonfuls of commercial yogurt or some yogurt from a previous batch of home made yogurt to the cup. This is the inoculation mixture.
Pour the inoculation mix into the milk. It is very important the temperature of the milk is well below 130 degrees and above 100 degrees. For best results keep the temperature between 108 and 112 degrees. At this temperature the culture grows well disease causing bacteria cannot invade the mixture. If the temperature is higher it will kill your culture and whatever you end up with will not be yogurt! Cover the pot and maintain this temperature until the yogurt has the consistency you like. This could be between four and twenty four hours. The time will vary depending upon the size of the inoculation culture, temperature, and lactose content of the milk and or the freshness (vitality) of the culture used. Any one or combination of these factors will increase time to complete the process.
Once the yogurt has the consistency you desire it can be packaged. I personally like to use old quart size commercial yogurt containers. Any glass jar or disposable plastic container may be used as long as it is clean. After the yogurt is packed it should be stored in the refrigerator. It will thicken as it is chilled. Letting the yogurt sit undisturbed will make it thicker.
Any sweetener can be used in yogurt. Sugar and honey are the most popular but fructose or artificial sweeteners can also be used. The natural sugars contained in fresh fruit make a great sweetener. Wash the fruit well, chop it up and toss it in. Some fruits do well when pressed or puréed to free up the sugars. The high acid content of the yogurt will naturally preserve the fruit to some extent.
Nuts and grains can be a treat in yogurt. Granola, almond, pecans and walnuts are wonderful in yogurt. Once you find a mix you like it can also be put into the ice cream freezer and it becomes frozen yogurt. This is a lot like ice cream but much easier to digest.
Lactose is a sugar that is present in milk. Some people do not produce the enzyme needed to digest lactose after childhood. This produces the condition known as lactose intolerance. The bacterial cultures used in yogurt making consume lactose and break it down into simpler sugars that the body can digest. For this reason the lactose intolerant person can often consume yogurt but not the milk it was made from.
In a healthy human natural flora exist in the digestive tract. These bacteria enhance the immune system and actually produce some vitamins needed in the body. The same bacteria also play a role in cleaning and elimination within the colon. The presences of these bacteria help to defend the body from invasions of other disease causing bacteria. Often a prescribed round of oral antibiotics will leave the body completely void of all bacteria. This bacteria free state of the body leaves the body vulnerable to invasion of bacteria that can cause disease. Consuming yogurt containing active cultures will help in the repopulation of the colon with beneficial bacteria. This pro biotic action of yogurt exists only when the yogurt consumed has active living cultures.
If you look on the internet you will find a lot of conflicting information on yogurt making. Some manufactures of yogurt making equipment claim all you need to do is mix a little left over yogurt together with cold milk, pour it into their appliance and you’re done in four hours! Do not be alarmed if you have seen other temperatures, recipes or culture sources on line. If you do it like we explain here it will work. If you like to experiment feel free to do so.
The DigiQII coupled with a “Power Raptor” relay is very versatile. This simple inexpensive combination can be used to control temperature on virtually any electric home appliance. Using an electric griddle, a steam table tray, Power Raptor and DigiQII together in the same fashion creates a sous vide cooking system.
In sous vide cooking the food is seasoned and prepped before sealing it in a vacuumed plastic bag. The entire package can be frozen and then later cooked in a temperature controlled water bath. This cooking method is taking the restaurant business by storm. It allows the portions to be split from bulk and cooked individually. Results are very reproducible. This process is slowly catching on in home kitchens. One of the things holding it back in the home kitchens is the price of the cooking unit. Prices start at over $800 and can be twice that price. With a DigiQII you can set up the entire package for a fraction of that cost.
Please do not forget the original use for the DigiQII. This device will control any air tight charcoal cooker to within five degrees of the set temperature until it runs out of charcoal. This makes temperature control on those long slow cooks a snap. The BBQ pros love it. Just look around at any BBQ cook off competition and you will see DigiQII units hanging on many of the cookers. It’s not rare to see the BBQGURU.COM banner flying in the camp of the grand champion!
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