Years ago I made yogurt using a recipe from Saul Sternberg. I still use the same ingredients — the basic point is to add about 1/2 cup powdered milk per quart of regular milk at the start — but I implement the temperature changes differently. Since I became interested in fermented foods, I’ve made yogurt a dozen times. Here’s what I’ve learned.
1. Makes a great condiment. I blogged about this. Store-bought yogurt, even the plain stuff, is too runny — not thick enough — nor sour enough to make this clear. The addition of powdered milk makes the yogurt thick enough to easily eat with anything, including meat. It improves the flavor of just about anything, especially if the yogurt is really sour. This might be the most important lesson since it means you can eat it at every meal and it makes cooking easier. I use spices much less now. The yogurt supplies complexity.
2. You can incubate it for days. I want it as strong as possible — not only because more sour (food writers euphemistically say tart) is better but also because the longer it ferments the more bacteria there will be. After a while it stops getting more sour and I stop. I routinely let it incubate one or two days, much longer than any recipe I’ve seen.
3. Preheating helps. Most recipes say you should heat the milk before you add the cultures. Some say this kills “bad” bacteria, which could compete with the bacteria you add. According to Harold McGee, the preheating denatures the milk proteins, which helps them trap liquid (whey). I did a little experiment in which I didn’t preheat some of the batches. Without preheating, the yogurt was much less solid. Supporting McGee.
4. Strauss yogurt better than Pavel yogurt. (Two popular Bay Area brands.) When I make a new batch I start it with store-bought yogurt; that works better than using what I have left. Side-by-side tasting showed that Strauss yogurt is more sour than Pavel yogurt. I made yogurt using each as the starter; the Strauss-started yogurt was clearly more sour than the Pavel-started yogurt.
5. Slow cooker works great. It is very easy to do the preheating via a crockpot (also called a slow cooker). I put it on high and wait 3-4 hours. This heats the milk to about 185 degrees F. Then I cool it down, add the cultures, and put the whole crockpot in the oven (set very low) to keep it warm for a few days. No spillage. I use a food thermometer to track the temperature. I got the idea from the Shangri-La Diet Forums.
6. Whole milk better than low-fat milk. Whole tasted better.
Re your No. 4: you don’t say why you think using a new starter works better than continuing the culture you already have. Of course, it’s your blog and you don’t have to, but my experience is the opposite. My old batch is a better starter than a new pot of yoghurt. It could be the brand, but I feel that the culture has adapted to the way I make, and like, my yoghurt.
Any experience with the room temperature yogurts?
Jeremy, I really don’t have any good idea why. Maybe long incubation kills bacteria. They run out of food.
Curious, I put yogurt in milk at room temperature and it didn’t turn into yogurt. More like kefir.
Seth,
I should have been more clear. I was referring to matsoni, viili and similar cultures. I like the yogurt I make, but the idea of not having to keep the culture warm is appealing.
Seth,
Do you know the specific carbohydrate diet recommends 24 hour incubated yogurt as the cornerstone of its stomach health program?
Curious, I haven’t tried those cultures.
Rose, I didn’t know that. That’s really interesting.
I’ve been meaning to make yogurt for a while – great to have these tips.
Pavel yogurt I know I’ve seen around, though I usually buy Fage. Who carries “Strauss”? (I guess it doesn’t matter – the principle is that store-bought yogurts work, so I don’t need to track down aged relatives for their yogurt culture. Cool.)
Seth,
Unlike most commercially available yogurt, Strauss is unpasteurized- a process that kills the bacteria (https://www.medicinenet.com/script/main/art.asp?articlekey=50610) . I am not familiar with Pavel yogurt, but a big deal was made out of Strauss being unpasteurized when I worked in the natural food industry. This may be the primary reason why it seems to work better.
I’m a huge fan of unpasteurized, well, anything, really. Unpasteurized apple juice (Apple-a-Day in Sonoma County makes some) tastes nothing like the sterile stuff you buy in boxes and is absolutely delicious. Pasteurization really does seem to make food taste a lot less interesting.
I’ve found that I can get really thick yogurt by straining it afterwards (same process used to make Greek yogurt), rather than adding powdered milk or anything else. When I make yogurt, I heat the milk to almost-boiling, cool it to 100-110 degrees, stir in the starter, put it into a pre-heated crock from my crockpot, wrap it in a beach towel, and let it sit on a Seed Starter mat for about 24 hours. Then to strain, I put a few layers of cheesecloth in a strainer and set it over a pot for about 4 hours. Turns out perfectly gorgeously thick, and simple.
I’m pondering trying to add a few different brands of yogurt (including Yakult drink) as a starter, to get as many kinds of bacteria as possible. This seems like it would be a good idea (to my untrained brain!). Thoughts on this?
bennetta. I agree. Raw milk cheese tastes a lot better than pasteurized-milk cheese.
Brody, I tried making yogurt using Yakult drink as a starter. I think it failed. When I eventually added — in addition — regular starter, there was no taste difference in the final product. Those are interesting production details, thanks.
RE: Yakult & other live culture sources…I wasn’t thinking taste difference as much as I was thinking about getting a wide variety of kinds of live cultures. I would imagine that greater variety of critters = better for us? I’m just guessing, I have no idea and no microbiology training.
Brody, I agree, more variety of bacteria is probably better. Because I couldn’t taste a difference in the resulting yogurt, I was unable to be sure that adding the Yakult had made a difference. Maybe all the Yakult bacteria died.
Seth,
Just one data point but my first batch of yougurt, I used a pint of store bought for the cultures. Good product quality.
Second batch I used a pint from the first. Not nearly as good as the first.
Slow Cooker (Crockpot) Yogurt
This is a simple and very effective way to make perfect yogurt using a crockpot….no need to use the oven or a thermometer:
Use whole milk or better yet, a good quality of powdered milk.
Add milk in whatever quantity desired to crockpot, adding an additional cup or so of milk powder to increase potency.
Cover and cook on Low for 2 1/2 hrs.
Keep covered (don’t peek!), disconnect crockpot power (remove plug from power source) and leave for 3 hours.
Mix whatever active yogurt starter (Yoplait Yoplus, plain or flavored works perfectly and contains Acidophilus) you want into the warm milk….. 2 or 3 tablespoons is enough.
Re-cover the unplugged crockpot, wrap the pot in a towel and leave overnight or 8 hours .Be sure not to open the pot during this period.
The yogurt will be thick and retain the original starter organisms.
Thanks, Kimo. I will try it. I am moving to Beijing tomorrow where I don’t have a oven in which to keep the yogurt warm. I think it should be easy to get a crockpot.
Seth,
The crockpot we used while living in Hong Kong and Singapore was a Chinese brand, and worked great…..so Happy Yogurt Making in exciting Beijing!
Some observations:
Yogurt made without denaturing the proteins by heating to 190F or above (in other words, just heat to 130) may result in a better Greek-style yogurt after straining because it will retain less of the whey liquid.
Waiting for a crockpot to heat half a gallon of milk up would drive me insane. I just use a metal pan on the stove. Then, if I want to get the process started sooner, to cool the yogurt to the desired temperature (incidentally, I start my fermentation at 129F or so, not 110F) I pour it into a cake pan. The milk cools several degrees F per minute faster in a cake pan than in the pan I heated it in.
I repour the milk back into my original pan, add the starter (I use a stick blender to mix it in), then cover the pan and put it in a styrofoam cooler for overnight.
RE: viability of starter: The starter I use is yogurt that I froze in ice cube trays, then put the frozen cubes in a ziploc bag. I have made successful yogurt from 2 year old frozen yogurt cubes in the past. I usually use what’s left over from my last batch as a starter, but after about 3 generations I will start fresh with a new frozen cube starter.
However, you could also just wrap the pan in a blanket and leave it on the counter and get good results.
I have also made yogurt without starter “accidentally” by leaving milk that had been heated up for drinking out overnight. This milk had already been heated in the microwave and I was going to drink it but forgot.
When I found it 2 days later it was yogurt. I suspect it got recolonized by bacteria once it dropped below 130 and acidophilic strains lowered the ph while it stayed in the 130F-105 F range.
There are lots of ways to make yogurt!
My overall point is that you don’t need to overstress about keeping the yogurt warm. Particularly if you start the fermentation at a higher temp like 120-129F, simply wrapping a pot with a blanket or towels will be enough insulation in most cases. Or putting it in a cardboard box with a towel and putting crumpled newspaper all around it.