- Your finished yogurt may have some clear, yellowish liquid on the top. This is whey, you can either discard it or stir it back in (see final note for more on whey).
- If your yogurt curdles, you may not have gotten it hot enough initially. When milk proteins reach 178F they are changed chemically so they are less likely to form curds. 180F gives you a couple of degrees for thermometer error. You may be able to whisk or puree your yogurt to a smoother texture, or you can turn it into yogurt cheese. (See final note.)
- Measure out starter and keep it in a clean jar in the fridge, or, to better prevent your yogurt from going wild (it will pick up new strains of bacteria each time you make yogurt and will eventually become unpleasantly sour) measure out multiple batches of starter and freeze them. This will give you much longer before you will have to purchase yogurt again.
- If your yogurt does not set,
- First, try culturing it a little longer (4-6 hours) with a little supplemental heat. Yogurt is mesophilic, meaning it will grow between about 70F-115F—if it feels warm to you, it’s great for yogurt. Putting a heating pad on the lid under the wraps helps maintain a perfect culturing temperature when my house is really cool in the winter.
- If it doesn’t smell like yogurt at all and there is a chance that you added your starter when the milk temperature was over 115F, add some more starter, set up your heating pad and re-culture (6-8 hours).
- If it still doesn’t take but your milk smells ok, use it in baking or to make a cream soup and try again with fresh milk and starter yogurt. Your starter was probably bad. A good starter will state “Contains live and active cultures” and have very few ingredients besides milk and the cultures. Alternatively, one can purchase freeze-dried cultures online (I have heard Cultures for Health is good), just make sure to purchase an “heirloom” culture if you want to save your own starter.
- A digital thermometer makes this nearly goof-proof. Set it to beep at 180F, at 115F and keep the probe inside to do periodic checks of your culturing temperature. Mine is similar to this one: http://www.walmart.com/ip/Taylor-Digital-Programmable-Thermometer/17167406
- To make greek yogurt, spread a clean, non-terry dishtowel or piece of muslin in a colander, put the colander inside a large bowl, pour in your yogurt and let it drain (in the fridge to stop the culturing process) until it reaches the thickness you desire. I find ½ volume suits our tastes. If you would like to continue draining, you can make yogurt cheese. You can continue in the colander or you can take the ends of your cloth, knot them and hang your yogurt over the bowl on a kitchen cabinet knob. Eventually it will reach cream cheese consistency and can be used in many of the same ways (though I’ve never made cheesecake with it…). The yellowy liquid in the bowl is whey. It is high in B vitamins, very acidic and worth finding a use for if you can. Look up “uses for whey” on the internet. You’ll see everything from recipes to medical uses to garden uses to animal uses—amazing!