| « Put Your Signature on a Drink | Pitchfork Dining (with a side of whining) » |
Feature Fri Jul 17 2009
Lab Report: Homemade Yogurt
Introduction/Statement of the Problem.
I really do love yogurt. I love the tangy flavor of Trader's Point's yogurt; I enjoy mixing in a bunch of Milk & Honey Granola for some crunch and sweetness. The benefits of probiotics on the digestive tract are well-known, and a friend's nutritionist mother once advised yogurt to alleviate my seasonal allergies. Since I've started taking my coffee black, it's my best chance for calcium many days.
However... I hate most yogurt. Most mass-produced brands are either runny and sourly foul-tasting, or solidified with thickeners to the point that the yogurt resembles some sort of fruit-based Jell-O. None of this compares to the horror of the "fruit" on the bottom of many yogurts. Not even factory farm, tastes-like-nothing fruit deserves to become part of a grayish-brown slurry beneath cultured milk.
So I gravitate toward the few reliable brands I've found--Trader's Point, certain brands of Greek yogurt, and the fruit-free varieties of Wallaby when I want something a bit more portable. They're all quite good, and quite expensive.
So I was quite interested when I read a couple of articles about how easy and cheap it was to make your own yogurt, and how good the resulting yogurt was. I mentioned the idea at my small office, and found out that one of my coworkers made his own yogurt twice a week, with a culture he brought back from a trip home to India. He offered to give me some starter, but for this experiment, I opted to use a commercial Greek brand anyone could buy.
Hypothesis.
My homemade yogurt would be tasty and cheaper than store-bought.
To complicate my experiment, I also decided to use two different kinds of milk: a local farm's whole milk and a standard commercial 2% milk. I'd read that yogurt made from the 2% milk would be inferior to the whole milk, so I decided to test it out.
Materials.
- 4 cups of Blue Marble Family Farm Whole Milk, purchased from Green Grocer Chicago. $5.99 (plus bottle deposit) per half gallon. I didn't realize until later that this was a cream line milk, which may have introduced error in the experiment.
- 4 cups of Lucerne 2% Reduced Fat Milk, purchased from Dominick's. $2.99 per gallon on the day it was purchased.
- 2 tbsp starter yogurt (I used Greek Gods brand Greek yogurt, mainly because it was available where I was shopping.)
- Beeline honey
- 2 quart pot
- Four large ceramic bowls
- Plastic wrap
- Sieve
- Cheesecloth
- Spoons and glasses
- Space heater
Procedure.
- For each batch of yogurt, I heated the milk in a 2 quart pot to the point that bubbles began to form around the edges of the pan. I then turned off the heat, and let the milk cool until it was baby bottle warm (that is, I tested it on the crook of my wrist; it was ready when that temperature felt comfortable).
- Pour the milk into a large ceramic bowl. Stir 1 tbsp of starter yogurt into the warm milk. Mix thoroughly, cover with plastic wrap, and let sit overnight in a warm place. I conducted my experiment during a cold snap, so I rigged a corner of my room with a space heater on low.
- The next day, line a sieve with cheesecloth, then pour the yogurt in and set this over another ceramic bowl. Let the yogurt drain until it reaches a consistency you'd like, which was 45 minutes for me. (One of the articles I read suggested you could keep the whey drained off of the yogurt and use it as a liquid in baking, but when I attempted this, the way seemed to kill my yeast. I wouldn't recommend it.)
- Store the yogurt in the fridge. It will keep for up to a week, but is best within the first few days.
Results and Observations.
Before I made the yogurt, I tasted both of the milks I'd chosen. It was at this point that I discovered the Blue Marble was cream line, with a thick plug of butterfat at the top of the bottle. I like this kind of milk, but I've never been able to shake it enough to disperse the chunks of fat completely, and doubt it could be done without the assistance of a paint mixer. Therefore, my sample of Blue Marble had little pellets of butterfat floating in it (not that I'm complaining). It coated my mouth completely, and the milk had a very rich, mild sweet flavor in addition to the velvety texture. The Lucerne tasted watery and somewhat paste-like in comparison.
During the heating process, the chunks of butterfat melted and hovered on the surface of the warm milk; I was concerned that it wouldn't integrate with the rest of the milk, but when I stirred in the yogurt, everything seemed to combine. There was some visible fat the next morning, after the yogurt had solidified, but by the time I stored it in the fridge, it was no longer noticeable.
One surprise--I'd imagined the thinner 2% milk would give off more whey during the draining process, but the whole milk yogurt gave off almost 1.5 cups, while the same amount of 2% milk shed a little under a cup of the liquid. If anyone knows what I could actually do with this liquid, I'd like to know.
Now, to the taste tests. The whole milk yogurt was terrific. It was thick, it was tangy without being sour, it was rich, and apart from the Trader's Point plain, it's the only yogurt I'd eat plain. The addition of a half-teaspoon of honey only slightly increased the sweetness, perhaps because the taste of the yogurt itself was so strong. The 2% milk was more sour than the whole milk, and not quite as good, but the addition of honey completely eliminated the sour flavor and brought it close to the flavor (if not the texture) of the whole milk yogurt.
I ended up using the whole milk yogurt as a straight "eating" yogurt, while the 2% milk went into a few smoothies. I also had each of the yogurts with a few mix-ins, including the aforementioned Milk & Honey granola. I also stirred in a spoonful of Blue Chair preserves from my last trip to Oakland, along with a little honey; this is how fruit should be incorporated into yogurt. One improvisation I ended up really enjoying with the 2% yogurt: a little bit of honey and a little bit of pomegranate molasses. I bought a some pom molasses for red pepper dip awhile ago, and love finding new ways to use the rest of the bottle. This one is quite tasty.
Conclusions.
The whole milk yogurt I made ranks right up there with my favorite store brands, but at a much lower cost (I still had half of that bottle of milk left over, after all). I probably won't use a cream line milk in any subsequent batches, but I'll likely stick to whole milk. My co-worker swears by Oberweis for his yogurt, but I may stick with a TJ house brand to cut down costs even more. I'm curious about what fat-free homemade yogurt would taste like, but I'm not likely to spend my time and money on what I'm pretty sure would be a weaker batch of yogurt. Further experimentation is called for, though.
In short: Success! I'll certainly be doing this again.
pk / July 17, 2009 7:18 AM
a few things:
the optimal temperature range, if you're actually measuring, is 112-116° F. i get the best results at around 113.
i just stir the whey back in. it happens the longer you let the yogurt cure. just time it to the point that it's beginning to separate, then take off the heat.
you can find a yogurterie on amazon for about $40-$50 or so. mine has been in constant use for 2 years twice a week, so the cost is worth it for consistent temperature management.