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Archive for the ‘Science!’ Category

This is a public service announcement for writers and other humans:

If you’ve ever confused stalactites with stalagmites, here’s a hint: mites crawl.

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Making yogurt is easy, affordable, and (if you’re a kitchen nerd like me) fun. It can also give you a much better product than you’ll find in stores. The process is simple: heat milk to get rid of existing bacteria and denature the proteins, cool it, then add good bacteria and give it some time to work. That’s it.

I like writing, so this recipe will be wordier than strictly necessary. Don’t let that make the process feel daunting! It isn’t.

The tricky bits, and there aren’t many, are in the details. It helps to have a thermometer. It helps to have an oversized heavy-bottomed pot, a few things like a canning funnel and conveniently-sized jars, kitchen towels to help keep the yogurt warm as it cultures, and a Post-it to keep you from hitting the oven’s on button with your yogurt inside (ask me how I know!).

None of those things are necessary, however.

Search for information on yogurt-making and you’ll find a variety of alternate recipes and methods, from counter-top to Crockpot. We’ve distilled that information and found a way that makes thick, tangy lactose-free yogurt and works for us. Tweak at will!

 

Yogurt, Plain but not Boring

Ingredients:

  • 1 gallon/4 Liters milk, whole or 2%
  • ½ C. plain yogurt with live and active cultures (~2 T. per quart)

1. Scald the milk: add milk to a large pot over low to medium-low heat. Cover and heat to 195℉, or until just simmering with bubbles forming around the edges.
2. Denature the protein: reduce heat to the lowest setting and hold the milk at 190-195℉ for 15 minutes.
3. Cool: remove from heat, uncover and cool to 115℉, or pleasantly warm to the skin.
4. Inoculate: Preheat the oven to 115℉, then turn off. Add a half cup of the milk to your yogurt starter, whisk together, then add the mixture to the milk and whisk until smooth. Leave in pot or move milk to containers. Fill one jar with ½ C. to use as starter for your next batch.
5. Culture: If using jars, place on a cookie sheet. Insulate containers with kitchen towels. Place in oven or other warm spot. Let sit for 6 to 20 hours, then store in the refrigerator.

Transfer the starter to the refrigerator after ~6 hours to keep bacteria healthy. Longer cultures produce thicker and tangier yogurt. If you’re lactose-intolerant, culture for 18 to 20 hours to give the bacteria time to digest the lactose for you. No pills necessary!

Bacteria at work. Yum.

. . . . . . . . . . . . . . . . . .

Those are the basics. For a distillation of the tips and tricks we’ve learned over the years, read on!

Notes:

  • You can make yogurt with lower-fat milks but the resulting taste tends to be chalky and not as nice. We use 2% because Mr. Man is reasonable. I prefer whole milk myself;)
  • We bump this up to 5+ liters of milk (that’s four bags if you’re in Canada) but keep the amount of starter the same; it works fine.
  • For your starter, you want a plain yogurt with minimal additives and no sweeteners. We’ve had the best luck with more industrial-strength brands like Dannon or Stonyfield or (in Canada) Astro or Western than with some of the boutique varieties. There are other culture sources (like chili peppers!) but the grocery store is the easiest way to get started. Whatever you choose, you want bacterial cultures that are tough and ready to work. Rawr!
  • The heating and cooling cycles are somewhat time-consuming. I don’t recommend rushing the heating part of this process as that way lies hard-to-clean pans and nasty flavors, but you can speed cooling by sitting the pot in a sink of cold water. Be careful not to splash or otherwise contaminate the milk.
  • There are ways to make mesophilic yogurt at room temperature without the heating and cooling cycle but this thermophilic method works for us.
  • Precise measurements aren’t required. You need enough starter for the bacteria to get off on the right foot, but as long as you have live cultures and eliminate any competitors by heating the milk, the good bacteria will have room to work. If the yogurt isn’t thickening as fast as you like, feel free to start your next batch with an extra tablespoon or so of starter, or give it another hour or two to set up.
  • The longevity of your starter will depend on the strength of the original bacterial strain and how you treat it. We often go six or more months before buying replacement starter, and we make yogurt about once a week. If your finished product isn’t as thick as before, takes longer to set up or (heaven forfend) smells off, it’s time for new starter. We keep the starter in its own container to avoid contamination, try not to let it culture longer than ~6-8 hours, and whisper encouragements. Your mileage may vary.
  • The jars we use (see below) are perfectly sized for our needs (Mr. Man strains one for breakfast, I now use two per smoothie) but you can use any option you like so long as it’s clean and non-reactive. You could re-use quart-sized yogurt containers or, if plastic isn’t your thing, mason jars, jam jars or the pot you used to make it.
  • If you like additives, add them just before serving. Jam, honey, fruit or other flavors are great additions.
  • Straining the yogurt to make a Greek-style thick version is also easy. Use a yogurt strainer, a bag of cheesecloth in a strainer over a bowl or with a filter in your drip coffee maker.
  • Strained yogurt is a great base for dip too. I like to add grated cucumber, lemon, minced garlic, salt, pepper and herbed Boursin with a sprinkling of bourbon-smoked paprika.

Optional: for your information only, here is the list of the tools we use to make yogurt:

  • 8-quart stainless pot
  • remote thermometer
  • stainless whisk
  • stainless cup measure
  • canning funnel
  • glass jars with lids
  • cookie sheet
  • kitchen towels
  • yogurt strainer
  • one yellow Post-it

We didn’t get all of these things at once, but as we realized we needed them and that we were in it for the yogurt long haul. I’ve found the remote thermometer to be the most useful tool for this, as it lets us be precise and to do other things while the milk is coming to temperature. We use an older version of this one, but there are a lot of options out there. Your needs may vary!

For even more information on the technique and science of making yogurt, I recommend these sources:

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If the world feels a bit weighty this morning, grab a cup of something hot, sit back and enjoy Mars.

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Ok, Google, now this is cool:) For anyone who has ever wanted to take the long (very long) view, there’s a new tool from Google.*

The Google Earth Engine gives users access to satellite imagery from as far back as 1984, and to build timelapse imagery that capture changes across the years.

Google Earth Engine combines a multi-petabyte catalog of satellite imagery and geospatial datasets with planetary-scale analysis capabilities and makes it available for scientists, researchers, and developers to detect changes, map trends, and quantify differences on the Earth’s surface.

Want to see what a timelapse looks like? Here is a short introductory video:

Want to make your own? No problem. Explore the built-in Timelapse features, integrate ready-to-use datasets on demographics, climate, imagery and more, or use your own code. (Check out the case studies from a variety of organizations focused on climate, health, and science, including this one on malaria risk mapping.)

You can also set up a tour to view more than one location. It’s fun, educational, persuasive, and easy to use. And because it’s Google, all this goodness is freely available. Now that U.S. government data may become less accessible, people and organizations interested in the long view need all the access they can get.


* Sadly, I’m not affiliated with Google, just a fan. Although like MIT and Slate and Scout and ASU (among others), Google would be a terrific sponsor for thoughtful new science fiction, don’t you think?

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While we wait to see if the European Space Agency’s ExoMars mission and its Schiaparelli lander makes it to the Martian surface intact, here is Neil deGrasse Tyson, astrophysicist and Frederick P. Rose Director of the Hayden Planetarium, taking on that most important of questions: are lightsabers physically possible?

Curious? I know I am!

 

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Today’s Thing I Like is nonfiction writing in general, and author Mary Roach in particular. If you aren’t familiar with her work, check out the books linked below or this interview with Seth Shostak at SETICon 2012.

Nonfiction can be a fiction writer’s best friend. At its best, it includes detailed, character-driven explorations of real-life situations and challenges, and can provide the sort of solid foundation a more speculative piece needs to succeed. I’ve mentioned this before, but avoiding abstractitis is key to good writing.

Specifically:

No matter how abstract your topic, how intangible, your first step is to find things you can drop on your foot.
— John Maguire

Nonfiction helps you do that, and Mary Roach is a great example of a quality nonfiction writer.

I have yet to read all of Roach’s books but Gulp: Adventures on the Alimentary Canal and Packing for Mars: The Curious Science of Life in the Void were terrific. Her books take a somewhat off-beat topic and delve in, deep. She’s also funny. The level of detail is satisfying and succeeds in painting an engaging portrait of her subject that is also educational. Packing for Mars, for example, is a great way for writers to familiarize themselves with the nitty gritty of space exploration, how we got to where we are now, and how we’ll get to where we’re going.

To note, if you’re interested in popular nonfiction about the intricacies of digestion or Mars exploration, check out Giulia Enders’ excellent Gut: The Inside Story of Our Body’s Most Underrated Organ, and Steve Squyres’ Roving Mars: Spirit, Opportunity, and the Exploration of the Red Planet.

Read, then write:)

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So I’m in my house one day last year as storm rolled in overhead. Dark clouds rained down, thunderous booms rumbled, and, off in the distance like God’s own strobe, lightning. I’m at my desk asking myself all the usual questions one does in such situations: Which direction is the storm tracking? Who pissed off the powers that be? Was that last strike closer? And that most critical question of the 21st century: will the power stay on long enough for me to meet my project deadline?

A little websploration later, and I discovered a very fun tool: Lightning Maps.

A project from Blitzortung.org, the site uses crowd-sourced data from a community of contributors with strike sensors:

“Blitzortung.org” is a lightning detection network for locating electromagnetic discharges in the atmosphere (lightning discharges) with VLF receivers based on the time of arrival (TOA) and time of group arrival (TOGA) method.

Lightning emits radio waves detectable from thousands of miles, if you have the right sensor. With more than 500 sensors, the network displays data from America, Europe and Oceania.

Think this is extra cool, have some skill with electronics and want to join in? Keep an eye on the Blitzortung forums to see when their next batch of sensors is available for purchase and deployment.

While the site makes it clear that the data are not suited for insurance or protection of life and property, it’s still a fun resource. I recommend it for anyone interested in a dynamic view of one of nature’s most dramatic forces.

Would you like to know more?

Check out how lightning works and the science of detection.

I prefer the beauty and simplicity of Lightning Maps but there are a number of alternatives. Visit Blitzortung.org for real-time and historical maps, or any of the alternative lightning maps at the World Wide Lightning Location Network (WWLLN), the European Cooperation for Lightning Detection (EUCLID), and of course, NASA.

Next time a big storm comes through I plan to cuddle up with a bowl of popcorn and ooh-ahh over the latest lightning strikes… at least until the power goes out:)

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