Scroll down for instructions on making yogurt. This first part is about my experiment with better culture and cheaper starter.
I had been making yogurt from skim milk powder for ten years. Recently the local Limestone Creamery started producing organic milk in glass bottles, so I'm coughing up the extra money to get something local. And the full fat milk makes amazing thick yogurt!
I used to buy powdered yogurt starter, but it's expensive. So, although I can make quite a few batches using some of my previous batch, eventually the culture gets too weak. Then I have to buy a plastic container of expensive yogurt, which may be thickened with gelatin and corn starch. I happened to have a jar of Natural Factors probiotic capsules containing 80% lactobacillus rhamnosus, 10% acidophilus, and 10% bifidus – meant to be taken 1-3 times a day. I wondered why this powdered lactobacillus couldn't be used as a yogurt starter. I Googled the idea of making yogurt with L. rhamnosus and found an article talking about rhamnosus' better survival rate in the gut and an experiment Canadian scientists did with using it to culture yogurt.
"Unfortunately, the usual yogurt cultures, Lactobacillus delbreukii sub-species bulgaricus and Streptococcus thermophilus, are neither bile-resistant nor acid-tolerant. They cannot survive in the intestinal tract, although they may help to lessen the symptoms of lactose intolerance.
But two of the most documented probiotic strains, Lactobacillus reuteri (formerly fermentum) RC-14 and Lactobacillus rhamnosus GR-1, can colonize the intestine and reduce recurrences of bacterial vaginosis, yeast vaginitis and urinary tract infections. They are bile-resistant and survive passage through the human gastrointestinal tract without inducing systemic immune or inflammatory responses."
"The scientists have used GR-1 in yogurt in a grass roots
humanitarian project in Tanzania and are planning more studies there.
They have since developed another yogurt with GR-1 and a Bifidobacterium
strain and have shown that it holds promise against allergy. None of
these applications has yet been picked up by industry."
So, I dissolved the contents of three capsules in 1/4 cup of freshly reconstituted skim milk powder warmed to the correct temperature. I put the two quarts of warmed milk in the yogurt maker and whisked in the mixture. I expected this culture to take longer to proliferate than a big envelope of starter, so I checked it after eight hours. It was still completely liquid. So I left it on for a total of 24 hours, then refrigerated it overnight. Perfect, very tasty, kind of runny but not stringy like a new batch from store yogurt is. I put aside half a cup in a glass jar in the fridge to use as my starter next time. I expect that batch will only take the usual five hours. (I haven't tried this using the crock pot method at the bottom of this page and I have no idea how long you'd have to incubate. I would think it would cool off too much.)
Note: This is purely experimental and I take no responsibility for anyone's health if they try this. I have zero qualification as a food person and I know nothing about bacteria.
My first day after eating this yogurt, I experienced a lot of stomach gas. I looked up 'gas from probiotics' and found this, which is what I suspected. "For example, a 4-week of a double-blind, placebo-controlled study
of 60 people with irritable bowel syndrome found that use of probiotics (friendly bacteria) reduced gas-related discomfort.
Probiotics are presumed to work by replacing gas-producing bacteria with others that are less likely to create gas.
Note: Initial use of probiotics reportedly can increase gas production for a short time."
October 2011 update: I've been making yogurt with three probiotic capsules dissolved in a little of the warmed milk and mixed into about 1/3 cup of yogurt saved from the previous batch. No weakening of the culture has happened for months and I'm incubating for five hours now. Very nice texture.
March 2015 update: I've been using Sacco Lyofast starter I order from Glengarry Cheesemaking. It's slow, so the yogurt stays in the maker for 12 hours. But it only takes 1/16 tsp of powder (a $10 pack lasts me many months in the freezer after I receive it in the mail) dissolved in some of the 44 degree C milk and no yogurt from the previous batch. This has been completely no-fail for a year or so and it's the least expensive yet! Super thick and creamy! I don't mind the scald/cool process, because I've learned to fill the sink really full with cold water and four big chunks of ice or freezies, so it only takes a few minutes stirring the pot floating in this to get it down to the right temperature for incubation.
HOW TO MAKE YOGURT
If you're using ordinary grocery store milk produced in large industrial dairies, you may as well save money and use milk powder. Making your own yogurt from instant skim milk powder saves money, plastic containers and all the refrigeration and shipping costs of fresh milk, plus it's quicker and simpler than scalding, then cooling fresh milk to a precise temperature. If you eat a lot of yogurt, you're defeating the purpose of eating vegetarian, because it takes lots of cattle to produce milk and all its attendant methane and CO2.
I have a Yogourmet yogurt maker, which has a 2 quart
tub. I set aside half a cup of my yogurt in a jar
for starter. It just keeps getting better.(New January 2011: use your slow-cooker. No need to buy a new $70 appliance! Scroll down.)
If you're a strict meat avoider, you won't like that I use gelatin, but you have to use way too much skim milk powder without it, if you want your skim milk yogurt nice and thick.
Put the empty tub into the yogurt maker and hold it down while pouring hot water into the space between. Plug it in.
Fill the inner tub with cold water to within an inch of the top and pour it into a stainless steel pot. Measure three cups of instant skim milk powder into the cold water and whisk it in. Put the thermometer on the side of the pot and stir constantly while heating the milk to 115˚ F (42˚ C).
In a cup, place 1/3 cup cold water and stir in 1 tbsp gelatin powder (cheaper at the bulk store than those envelopes). Mix in your half cup of yogurt.
the hot milk into the tub.
Use the whisk to stir in the starter & gelatin
Cover and leave for 4 1/2 to 5 hours. Longer will only make it more tart, not thicker. Make sure the inner lid is on tight before trying to lift it out.
Cool overnight before using the whisk to stir the finished yogurt.
Plug in your 4 quart crockpot and turn to low. Add an entire half gallon of milk. Cover and cook on low for 2 1/2 hours.
Unplug your crockpot. Leave the cover on, and let it sit for 3 hours.
When 3 hours have passed, scoop out 2 cups of the warmish milk and put it in a bowl. Whisk in 1/2 cup of store-bought live/active culture yogurt. Then dump the bowl contents back into the crockpot. Stir to combine.
Put the lid back on your crockpot. Keep it unplugged, and wrap a heavy bath towel all the way around the crock for insulation.
Go to bed, or let it sit for 8 hours.
Cool at least 8 hours in the fridge.
Thanks to Stephanie O'dea