Teacology

Tea, with an Ecological Approach


3 Comments

Brewing Iced Tea to Minimize Energy Usage

This post is an expanded, follow-up post to my original post Energy Saving Tips for Making Iced Tea.  I also expounded these same ideas in RateTea’s article on iced tea.

The hottest part of summer is approaching, and I’ve already brewed up my several first batches of iced tea.  As subscribers to my old blog and readers of the articles on RateTea will likely know, I’m a die-hard advocate of brewing your own iced tea, ideally from loose-leaf, rather than purchasing pre-brewed bottled or “ready to drink” teas.  But here I’m going to take for granted that people are interested in making their own iced tea at home, and I’m going to focus on how to do so in a way that uses the least energy.  I brew a lot of iced tea: two batches a day of four cups each in the hottest part of the summer, so I’ve had an opportunity to experiment and develop a method that results in superior flavor but is fast, easy, and energy efficient.

At the end of the article, you’ll also find an explanation of how drinking iced tea, regardless of how you brew it, can help you further reduce your energy usage!

Why is minimizing energy usage important?

Energy efficiency is one issue that I care about a lot.  Most electricity in the U.S. in generated in ways that have numerous negative impacts on the environment: the burning of coal and natural gas releases both carbon dioxide, a greenhouse gas, and various pollutants into the atmosphere.  Coal burning for electricity generation is a major source of mercury, which contaminates seafood like tuna, making it unsafe for consumption.  I use EDF’s Seafood Selector and it concerns me how many types of seafood are contaminated with unsafe levels of mercury.  Even cleaner forms of energy like hydro, wind, and solar still have some negative impacts on the environment.

A coal fired plant, with big smokestacks, and a lake and beach in the foreground

Although renewable energy production in the U.S. has been increasing, about half [source] of the electricity here still comes from coal-fired plants like this one in Calumet Park.  Public Domain Photo by the US EPA, taken from Wikimedia Commons.

Global climate change, which is directly related to energy usage, poses a direct threat to numerous countries, through many different mechanisms.  Sea level rise threatens low-lying areas as diverse as Florida, New Jersey, and Bangladesh, and the changing climate threatens both ecosystems and agricultural development.  Climate change is already negatively impacting the industry that produces tea and herbs.  For example, tea production in more arid regions of the world like Kenya is threatened by periods of prolonged drought, and rooibos production in South Africa has also faced threats from climate change.  The Ethical Tea Partnership has a page on the negative impacts of climate change on the tea industry.

In addition to the long-term benefits of reducing your energy usage, you will see an immediate benefit as well: saving money on your electric bill.  I think people with a broad range of views on political and environmental issues can agree that reducing energy usage is a good thing.

How does brewing iced tea use energy?  How can we reduce these uses?

Making your own fresh-brewed iced tea uses energy in two ways: heating and cooling.  In order to minimize your energy usage when making up a batch of iced tea, you need to minimize both of these processes.  People who have central air or an air-conditioned kitchen will benefit doubly from reducing heating, because any waste heat generated by your heating method will need to be pumped out of your living space by the air conditioner, at additional cost.

Here is my method:

  1. Brew a very small amount of concentrated tea with hot water.  This minimizes the energy used for heating.  You can try cold brewing (steeping the tea directly in cold water), but this doesn’t work well with all types of tea.
  2. Let the brewed tea cool to room temperature.  I do this quickly by placing the tea in a closed jar, and setting it in a pot which I fill with cold water from the tap.  This chills the water to the temperature of the cold water in your home, without using any energy for cooling, thus minimizing your cooling costs.
  3. Dilute the tea to taste with cold or room temperature water.
  4. Chill the tea or, for quick results, pour over ice.

For the fastest results, you can skip step 2 and condense steps 3 and 4 by filling a glass, jar, or pitcher with ice and pouring the hot tea on top of the ice, adding any cold water if necessary for additional volume.

Below is an illustration of this process.  Here I steeped Ahmad Tea’s Ceylon, one of my favorite teas for use as iced tea.  Note the dark, concentrated color in the lower-left.  Here, I steeped this tea at quadruple strength (four teaspoons of leaf in one cup of water), because I planned to make four cups.  The upper right panel shows the tea once it had been diluted to the proper strength.  I put this jar in the fridge to chill, but only after I poured myself one cup, pouring over ice (lower left) to produce the cup pictured in the lower right.  I used a kimchi jar, which I have found to be quite heat-resistant (and which I always have available, as I eat a lot of kimchi).  It’s important to take care with your choice of a glass vessel, as pouring hot liquids into generic glass can sometimes cause it to shatter.

Four photos showing concentrated iced tea, diluted iced tea, a glass of ice, and a glass of iced tea

An illustration of my process for making iced tea

There are a few other supplemental tips that you can use to further minimize your energy usage.

  • Consider how you are heating the water:
    • Microwaves are one of the worst options, being considerably less efficient than a typical electric stove.  If you’re not convinced, read this comparison in Home Energy Magazine.  Home Energy Magazine, by the way, is a great place for finding more energy-saving tips.
    • If you have a gas stove, unless your electricity comes from a clean, sustainable source, using a gas stove is better than anything with an electric element, because a gas stove converts 100% of stored energy to heat, whereas when using electricity, only a small portion of the stored energy in the fuel used to generate the electricity is converted to electricity–most is released as waste heat at the point of generation, and more is lost through wires in transmission.
    • If you live in a state with electric choice (like Pennsylvania or Texas), choose a sustainable electricity generator like Green Mountain Energy, to minimize the environmental impact of your electricity usage.
  • Choose a cool day or time of day (early morning is typically the coolest time of day) to make large batches of ice or chill large batches of water or iced tea.  Refridgerators and freezers need to work harder on hot days.  It doesn’t matter if you have central air or if the refridgerator is in a room directly affected by outdoor temperature–any of the heat your fridge pumps out into your home will need to be pumped out again by the air conditioner, which has to work harder when it’s hot outdoors.
  • Follow general best practices for refrigeration.  Try to keep your fridge reasonably full; if you don’t have stuff to put in it, you can keep it full of jugs of water and put bags of ice in the freezer.  Make sure the coils on the back of your fridge are clean, and that the refrigerator has enough space behind it to allow good air circulation.  Check the seal on the door to make sure it is holding the air in.

Energy usage is a surprisingly deep topic, in that there is virtually always more you can do to reduce your energy usage.  Some energy-saving tips are easier to implement or more practical than others, but I hope that you have at least found some tips above which will help you to prepare iced tea in an environmentally-sound manner that also results in a superior-tasting batch of tea to drink.

One of the reasons I have gone so deep into this topic here is that I think the ideas presented here have broad applicability.  In the global scheme of things, the amount of energy used in making iced tea is tiny compared to the amount of energy consumed by numerous other things.  But the knowledge and ways of thinking that can be used to conserve energy are universal.  Processes that generate heat and cooling are at the heart of energy usage in homes, businesses, and industry, and  the ideas communicated here are universal and can be applied to far more than just the making of a cup or pitcher of iced tea.

Weighing Conservation of Water vs. Electricity

There are some parts of the U.S. and parts of the world, where water scarcity is a more pressing issue than energy usage.  Where I live, there is little need for water conservation, and the negative impacts of electricity use far outweigh the extra water used.  The same is true of costs: typical electricity usage tends to be much more costly in financial terms than typical water usage, at the rates charged by most municipal governments in the U.S.  But there are a few places where these rules do not completely hold.  In the southwestern U.S., water use has major negative environmental impacts, such as destroying the ecosystem in the Colorado river delta.  And in rural areas, people who drink well water often need to use electricity to pump their water, so conserving water is important for conserving electricity.

Lake mead, with dry hillsides and dark blue water

Lake mead, used as a reservoir for cities in the Southwest.  This water would have naturally flowed into the Colorado river delta, supporting a rich delta ecosystem, and an estuarine ecosystem in the Gulf of California. Photo by Rick Pecoraro, licensed under CC BY 2.0.

The method I described above uses additional water at one step, using a bath of cold water from the tap to cool down the jar of hot tea.  If you live in an area where water is scarce, or where you need to use electricity to pump your water, you can skip this step and opt for a slower cool-down to room temperature.

One Final Note: Cold Drinks Can Reduce the Need for Air Conditioning

There is an additional way that iced tea and other cold beverages, regardless of how you prepare them, can reduce your home energy usage.  If you keep your home air conditioned, continually drinking iced tea during the hottest hours can help your body to stay cool, enabling you to feel comfortable in a warmer environment.  This can allow you to set your thermostat higher in the hot weather, while still being comfortable.

What do you think?

  • How do you brew iced tea?  Do you already use any of these tips here?  Did you find any new pointers that you want to try out?
  • Have you had much success with cold-brewing?  Do you have any advice for people who wish to attempt cold-brewing?
  • How much do you think about energy saving in general?  Have you found some of the ideas and concepts in this post helpful in other aspects of your life, in terms of providing things you can do that can reduce your energy usage?


7 Comments

Adding Citric Acid to Teas or Herbal Blends

This post is inspired by an old post adding citric acid to teas, but it is much more than a rewrite of that post.

Most of us are familiar with the practice of adding lemon or lemon juice to tea.  The effect of adding lemon juice is most evident in black tea, producing an immediate chemical change in the tea, usually resulting in a noticeably lighter color, and a cup that is somewhat less bitter and astringent, but more sour.  A practice that is less familiar is one that some mainstream tea manufacturers do, particularly those dealing in herbal blends, which is adding citric acid to teas.

The following photo is by André Karwath and is licensed under CC BY-SA 2.5.

A whole lemon and a sliced lemon, white background

Citric acid is responsible for the characteristic sour flavor of lemons and lemon juice.

I was genuinely surprised when I first saw citric acid on the ingredient list of a packaged box of herbal teas.  This would not so much surprise me for a bottled or “ready-to-drink” tea, but for a tea bag, it was quite unexpected.  I think of herbal teas as being something that is made strictly from dried plant ingredients, so I do not expect to find an added pure chemical ingredient.  Some of the mainstream teas that include added citric acid are Celestial Seasonings’ Country Peach Passion and Lemon Zinger, and Tazo’s Passion and Calm.

On Citric Acid – The Chemical and its Production

Citric acid is a common organic acid that is named (and best-known) for being the main acid that imparts the characteristic sour flavor to citrus fruits like lemon and lime.  It is a common and safe food additive, used to impart a sour flavor to food and drink.  It can be isolated from citrus fruits, but is also commercially produced on a larger scale by using mold, such as Asperillus niger, to ferment sugar.

Citric acid is a pretty basic chemical in biochemistry.  It plays an essential role in all aerobic (oxygen-respiring) organisms through the citric acid cycle, also known as the Krebs cycle.  Here is a molecular diagram, for the chemistry-minded among us:

Graphical representation of the citric acid molecule

A graphical representation of the citric acid molecule

As someone who is highly skeptical of highly refined food additives, especially ones that consist of a single chemical, a natural question for me is: is added citric acid safe?

There’s not much to worry about with respect to citric acid, beyond its sourness.  Everything I’ve ever learned about it has taught me that it’s safe as a food additive.  However, the acidity itself though can sometimes be a concern.  For example, acidic drinks can soften tooth enamel, so it’s not a great idea to brush your teeth directly after drinking a cup of sour-tasting herbal tea.  Acidic drinks can also sting or irritate the mouth, especially if there is already a sensitive area like a burn.

Added Citric Acid is Not Necessary to Make Herbal Blends Sour

When I first discovered that some herbal teas contained added citric acid, I was curious to see which blends contained it and which did not.  One thing that surprised me was that the blends that were most sour did not necessarily correspond to the ones with added citric acid.

As examples, Celestial Seasonings Country Peach Passion and Tazo Calm are not among the most sour of herbal teas out there, but the famously sour Red Zinger does not (although some of the Zinger series blends do).  This is because Red Zinger uses Hibiscus as the main ingredient.  Hibiscus on its own, when brewed as an herbal tea, is intensely sour.

This photo was contributed by Popperipopp and is licensed under CC BY 3.0.

Dried hibiscus sepals, pink and dark purple in color

Sepals of the Hibiscus sabdariffa plant are a whole ingredient that can be added to tea or herbal blends to impart a sour flavor.

Why do tea companies not always use hibiscus?  It may be due to its color, and its peculiar flavor and aroma.  Even small amounts of hibiscus impart an intense purple-red color that may not be desirable in all blends.  But hibiscus also has a characteristic aroma, which I describe as being somewhat like berries but also a lot like cooked fruit or jam.  I sometimes find this aroma a bit overpowering, so it makes sense that companies would want to look for other ways to make their blends sour.

What do you think?  How do you feel about added citric acid in tea or herbal blends?

Here are some questions that you can answer in the comments, or in a follow-up blog post of your own.

  • Did you know that some tea companies add citric acid to their herbal blends, or is this a new realization for you?
  • Are you bothered by the practice of adding citric acid rather than relying on whole ingredients like herbs or spices, or is it fine with you?
  • How do you feel about sour-tasting blends in general?  Do you tend to like or dislike them?  How sour is too sour to you?
  • Do you ever add lemon to your tea?

My personal opinion?  I don’t have a big problem with added citric acid, but I think I would prefer blends made from whole ingredients.  Either way, I don’t like sour tastes much in my tea or herb tea.  I avoid both added citric acid, and blends that have too much hibiscus or other naturally-sour whole ingredients.