Listener Mail: Don't Throw the House Out the Window

But I should be back with all new listener mail on Monday then, and we'll have other new episodes for you sometime that week, I believe on Wednesday. So right on to your messages. This first message comes from Raphael and it's a response to our episodes on t Rafael says, Hello, Robert and Joe. I just finished part three of your Exploration of Tea, and I wanted to say I really

enjoyed these episodes. I'm not a big tea drinker, though various tea varieties seem to proliferate in our kitchen cabinet. That said, Rob's poetry readings made me brew a cup immediately. As a food scientist, I always appreciate episodes where you get into the history, science, and culture of foods. What put the t series over the top for me was the digression in part three on the topics of reology

and philosophy. This is why I love your show. I wanted to expand on a few comments you made in part two while talking about you lose preference for blue glazed teacups. Uh and plenty of the elder I couldn't agree more with your point that visual presentation can really influence our perception of the flavor of foods and beverages. I've been involved in proprietary research that showed that changing food color can influence taste perception. Broadly speaking, the effect

of color on food is well known and significant. A quick web search found an open access review by Charles Spence titled on the psychological impact of food color. Flavor, intensity, detection thresholds, and even basic flavor identification can all be manipulated with color changes. It is amazing what a little

food coloring can do. Uh. Yes, Raphael, that is true, and so we made general reference in the episode to the idea that say, changing the color of the plates or cups in which food and beverage are presented can affect the perception of the properties of that food or beverage. I wanted to highlight a few specifics about the background color, in particular because that was the original context youlu talking

about blue glaze teacup. So how much does the color of a cup or a plate affect what you taste or or how you consume food? I found a review article but the same author you mentioned, Raphael This is also by Charles spin Charles Spence is a psychologist at Oxford University who studies food perception. UH. This was a

different review. It was called Background Color and its Impact on Food Perception and Behavior, published in Food Quality and Preference in the year eighteen and so after reviewing the existing research as of this year, Spence writes, UH, this

year being when it was published. Spence writes that there is clear evidence that quote, while people obviously cannot literally taste the plate, the color of the plate, bowl, glass, cup, cutlery, pot, and package in slash against which a product is seen can certainly influence how appealing of food looks, what it tastes like, and even how much we end up consuming

and or serving ourselves. However, that the interesting thing I found from reading His conclusions is that background color and food perception relationships are not static and linear, they are dying amic and complex. So it's not just like, oh, food tastes better on a red plate or something like that. Instead, Spence writes that one example is a trend of findings that desserts taste sweeter when served off of white plates, then when served off of black plates. And meanwhile, black

plates may enhance the experience of savory dishes. And so the dynamic aspect is that whether these effects are desirable or not may depend on the properties of the food itself and the expectations of the diner. So uh, if a if a dessert tends to taste sweeter off of a white plate, and that dessert is already considered too sweet in isolation, it may actually be more enjoyable if it's consumed off of a black plate, dulling the sweetness,

Whereas the opposite holds true as well. A dessert that people consider not sweet enough can be enhanced by a white plate, heightening the perception of sweetness. And there are other interesting findings well that Uspence mentioned and his conclusions.

One is that when a food is considered an unhealthy indulgence, people seem to naturally eat less of it when it is presented on a red plate, and the reasons for these effects of color on food perception and consumption behavior are still up for debate, like do the colors function by triggering environmentally salient associations between certain colors and certain

types of nutrient contents? You know? Could it be that when you see this color in the natural environment, it often has this kind of uh, maybe a poisoning danger associated with it, or this kind of nutrient reward associated with it? Or are these associations learned or are they simply a result of color effects on mood? And questions like that, uh, And I think those are not fully solved yet. But anyway, back to Rafhaile's message, however, I think you may both have done Plenty wrong. There was

a bit of chuckling over Plenty. This is our reference to Plenty the elder. Uh. There was a bit of chuckling over Plenty writing that sappa boiled in copper pots tasted bitter, while the same beverage boiled in lead pots tasted sweet. At least in this case, Plenty may have been accurately reporting a real phenomenon. If his starting grape juice had been sitting around long enough to form some acetic acid, Plenty may well have been cooking up some

lead acetate, also known as sugar of lead. Lead acetate is a toxic compound with a sweet taste. By the same token, dissolved copper has a metallic and bitter taste at least according to determination of the taste threshold of copper in water by Zacharias. At all the lead pot might actually have made the sappa taste sweet, though also poisonous. And to come back on this, Yes, Raphael, this is a great point to explore for those of you who don't know or don't remember the original context of this

little digression we did some years back. Rob and I had an episode where we talked about people intentionally consuming lead acetate as a medicine or a food additive, which you absolutely should not do. It is highly poisonous. But one of the examples we discussed was a passage in Plenty of the Elder where he writes that leaden pots and not copper pots, should be used for the production

of sappa. Sappa was a like a sweet syrup used by the ancient Romans, I think used kind of in the way that you know a bartender might use simple syrup today. It was a sweetening agent, though not as sweet as today's simple syrup would be, but um, it was a It was a sweetening agent to syrup that the ancient Romans made by boiling down and reducing a liquid called must, which was a type of lightly fermented

grape juice, kind of a weak wine. And the reasoning we discussed in that episode is exactly what Raphael is saying here that Plenty's recommendation was probably because boiling must in a metal pot would cause some chemical reaction between the acetic acid, which is the type of acid that is in vinegar, uh and uh, the acetic acid in

the juice and the metal walls of the pot. So if it's copper pot, this is going to result in copper acetate salts, which tastes disgusting, bitter, nasty, metallic flavor. And uh. If you boil it in a lead pot, on the other hand, the same thing happens, but it forms lead acetate, which is very poisonous but is also sweet. So yes, Raphael, your analysis is spot on. I think Plenty's advice about pot metal selection was exactly right from a flavor point of view, just without any understanding of

the dire health effects that could flow from this. Uh And to supplement this, I wanted to read from the entry on sugar of lead in the Oxford Companion to Sugar and Sweets. This entry was written by the American

chemist Michelle in FRANCEL. Francile Wrights quote. Chemical analysis of sappa produced according to the recipes dating from the Ascle Roman period using kettles of similar metallic composition as those found at Pompeii and other sites, suggests that the lead content of sappa was eight hundred and fifty milligrams per leader, many thousand times higher than what is generally allowable in drinking water, even diluted and used sparingly. Sweetening with sappa

posed a serious risk. However, to come back on what you said, Raphael, about the validity of Plenty's idea that that it really did make the sapa sweeter to use a lead pot France, Will argues in this entry in the Oxford Handbook here that the amount of sugar of lead produced by boiling down a pot of must probably would not have made a major contribution to the sweetness of the syrup, because it would only represent a taste change equivalent to adding a pinch of sugar to a

product that was already pretty sweet. So you know this, sappa would already have levels of glucose and fructose equivalent to roughly one cup of table sugar per leader of liquid. So in the specific example of sappa, the preference for lead pots over copper might be more due to the fact that lead pots do not produce the disgusting bitter copper flavor than to the small amount of additional sweetness

that the lead would add. And while we're on the subject, I just thought I should add that the practice of intentionally adding lead to food products was not limited to this sweetening effect for sappa. In ancient Rome. Up until the nineteenth and twentieth centuries, lead metal and lead salts

were used in a number of ways. Were used as a preservative and an antimicrobial agent, and just got into foods because people used lead machinery and cookware to make foods with, but it was used as an antimicrobial agent and beverages like wine and cider because sugar lead is poisonous to bacteria. In the same way it's poisonous to us and Francile writes quote Vintner's observed the filtering fermentation mixtures through lead sieves or dropping some lead shot into

bottled wine noticeably reduced spoilage. A firm connection between ingesting low levels of lead in these beverages and lead poisoning was finally made in the early nineteenth century, in part because of the correlation between outbreaks of colic of Potu

uh and the arrival of wine shipments containing lead. Colic of Potu, by the way, is the name for an originally mysterious condition also known as Devonshare colic, which was observed I believe beginning in the seventeenth century, but it affected uh people in France I think, mostly through wine, and people in Devonshire, England through their cider. In both cases it was eventually determined that lead was the was the culprit lead used as a preservative in some cases,

or because of production processes using lead lined machines. Finally, coming back to the end of Raphael's message here file rites. Lastly, I have noticed Joe building confidence in understanding rayology and fluid dynamics over the years. I don't know about that, Raphael, but I appreciate uh. He says, you both did a great job making the physics behind the teapot effect more accessible. Reyology is one of those areas where the concepts can be really hard to understand, but once you do, you

will see its principles in action everywhere, especially in the kitchen. Also, I can confirm that the periodically mentioned on the rayology of cats is hilarious to rayologists in equals three sample of three. I think thanks for the great show, Rafael. Ps. Unsurprisingly, I'm also a fan of Lauren and Annie over at Savor. Everyone should go listen to them too. So yes, thank you for the message, Rafael, and absolutely people should go

check out Savor. That is a podcast hosted by our friends Lauren Vogelbaum and Annie Reese and it's a wonderful home for food nerds everywhere. Again, it is called Savor s A v O R. You can find it wherever you get your podcasts. Tell him we sent you. Okay, This next message about Tea comes from Stephanie. Stephanie says, Hello, I was listening to the first episode on t and you've got about nine of the way to explaining one

of my favorite facts about tea. In English, the word tea can refer to all sorts of beverages, including those made with Camillia senensis, but also herbal teas and other usually hot steeped beverages. The French language differentiates between unta rhymes with bay made with Camillia senensis and untizan made with other plants. The lack of this easy distinction in

English can definitely cause some confusion. Interestingly, French also differentiates between caffeine and teen or I think in English, I've heard it pronounced theene, but tayene or theene the caffeine found in Camilia senensis in common parlance. At least that distinction is made in the Quebec dialect of my husband

and in laws. I had wrongly assumed that this was another example of French being more precise about tea related vocabulary than English, and thought there were two different chemicals, caffeine and taine. I only realized through listening to your episode that they are in fact the same compound, despite the different names. I also learned today the English word theene, which means the same as the French one, but which I had never heard before despite being an avid drinker

of teas and tissan's. Thanks for always expanding my knowledge and my concept of what stuff can be fascinating. Stephanie, Thank you, Stephanie. Okay, this next message is from Andreas. Andrea said, Dear Robert, Dear Joe, I'm a longtime listener and currently very much enjoying your episodes about te I write in to tell you a little bit about a t tradition in Germany, especially in the region called East Frisia.

Even though I live around two hours removed from that area, several vacations there made me really appreciate the fine drink called post freeze and tea. It is a quite strong blend of black teas, almost exclusively a psalm tea, and it never fails to pick me up on those gray and rainy days. There is a special ritual to drink it. I copied a text from a German website of one of the traditional suppliers of the tea and ran it through an Ai translation for you to enjoy. Thanks for

all the great content. I hope you will do this forever. Regards Andreas. Okay, so this is how you make the post freeze and tea, at least as mediated through an AI translator. It says placed the loose tea leaves in a well preheated pot of fresh boiling water so that they are covered. Allowed the tea to steep for three to five minutes, preferably in a kettle or teapot. Then

fill the fragrant infusion with the remaining water. It is best to pour the finished teeth through a strainer into a preheated serving pot and keep it warm on a tea warmer. Now comes the pleasure in the cup, as East Frisians love it. First, a cluntia, a white sugar candy, is placed in the cup. When the hot tea is poured over it, the rock candy crackles, creating anticipation and

giving the tea a fine sweetness as it melts. A few drops of fresh, high percentage cream, which is not stirred in the East Frisian way, conjures up the famous vulcia, the little cloud, which makes the enjoyment of the tea perfect. The cream is added to the tea counterclockwise to symbolically stop time. That's nice. East Frisian connoisseurs divide the unstirred experience in to three phases. The first sip of tea with cream is followed by the second sip of tea

with cream. Something might have been lost in translation there. I'm not sure which completes the three tiered pleasure with the sweet finish. It offers the courtesy to enjoy at least three cups, which is why it is not called for nothing. Dree u dree dry dree st uh ost Friesian wrecked or three is East Frisian right, It's better by a country mile. The small teaspoon is only used to signal to the host after the tea has been poured into the cup that you do not want any more.

So thanks for sharing this, Andreas, and I've never heard of this before I looked it up. I encourage everyone to go look up images of East Friesian tea to see the patterns left by the unstirred cream. That seems to be the most interesting thing about it, the the

visual uh flower. Coming back to the how the appearance of food affects the flavor, the appearance of the unstirred cream dropped into the cup forms mostly beautiful but occasionally disgusting shapes, and I only say, disgusting, because there are some cases where it looks like maybe it's when there's

a bit more dribbling of individual drops. To me, this has the unfortunate effect of looking like the spots that form in a petrie dish when bacterial colonies are blooming, especially when the you know, the translucence of the tea naturally somewhat resembles an agar plate. But in most cases this tea looks lovely. I think it's a nice variation on that other beverage art tradition, the designs that people

make in latte foam. So if latte foam is a bit more controlled, a bit more representative, maybe making a hard or a cat face or whatever, the East Frisian tea is a bit more abstract. It's kind of fractal, an emergent, but very cool. Thank you, Andreas. Okay. I think we're gonna finish up to day with a message

about weird House cinema. This one comes from Pat and it's in response to our Weird House Cinema episode on let Sleeping corpses Lie, which was the nineteen seventy four Italian Spanish horror movie about how science is bad and if we don't kill Science once and for all, it will inevitably raise the dead from their graves with ultrasonic radiation. Uh. This movie was a real hoot to cover, and one thing we discovered in that episode was this movie has

a very long list of alternate titles. One was let Sleeping corpses Lie, which is okay, but others were things like the Living Dead Manchester Morgue, which is strange because the movie does not take place at a Manchester morgue, though I think some scenes were shot at a Manchester adjacent morgue or hospital. Uh. And finally, there was one title of the movie which was Don't Open the Window, which as far as we could tell, has absolutely nothing to do with the film at all. A onto the message,

Pat says Robert Joe. The last Weird House was a good one. I'll have to see this one. You guys talked about the strangeness of one of the release titles, don't Open the Window. Seems that this phrase is idiomatic in Spanish and means quote to bring something to light. It seems the title suggests that the enemy Science is invoked and leads to horror. Thanks for all the fun, Pat, Pat I've never heard that idiom before. I tried to

kind of look it up and didn't find much. But I believe you other Spanish speakers in the audience please right in about that. What's the deal with with opening the window? Is science opening the window of knowledge? And thus according to this movie, uh, you know, don't open

the window, like don't don't do those experiments. I'm not sure, but despite never hearing that one, I do know of a a window idiom in Spanish which is tire lacasa poor love antana, which basically means uh to well, literally it means to throw the house out the window, and from what I understand, this means like to go all out, as we say in English, to spend a lot of money on something, to spare no expense. That's a really good one. Okay, I think that does it for the

mail bag today. Just a reminder that we will be running Vault episodes this week and Tuesday of next week while Rob and I are out. But I should be back with a new Listener mail episode on Monday, and then we will have more new episodes for you that week, probably on Wednesday, March one. In the meantime, if you're new here, this is the Stuff to Blow your Mind podcast. Please subscribe wherever you get your podcasts uh we. We do different episodes throughout the week. Our core episodes publish

every Tuesday and Thursday. Those are most often about science in one way or another, but we like to jump across disciplines. On Monday's we read back listener mail in episodes like this one, though usually my co host Robert Lamb is here with me. On Wednesdays we do a short form scripted episode called The Artifact or the Monster Fact. And then on Friday's, when the week is done, it's time for Weird House Cinema, which is an episode where

Rob and I feature and discuss a weird movie. They can be good, they can be bad, they can be classic, they can be obscure. All movies are fair game as long as they are weird. And then, finally, on Saturday's we uh we highlight an episode from the vault from the olden days uh Big thanks to our audio producer

J J. Pauseway. If you would like to get in touch with us with feedback on this episode or any other, to suggest a topic for the future, or just to say hello, you can email us at contact at Stuff to Blow Your Mind dot com Stuff to Blow your Mind. It's a production of I heart Radio. For more podcasts my heart Radio, visit the iHeart Radio app, Apple Podcasts, or wherever you listen to your favorite shows.