What is sour?

Or, for that matter, sweet, bitter, astringent, citrus, or woody?

I had some teas with two tea friends today, and one of the first issues we dealt with was the question of sourness.  Apparently, even though I thought I was pretty clear, they were wondering what I mean when I say “sour” on my blog when using it to describe a tea – something I thought of as pretty obvious and self-explanatory is, apparently, anything but.  This, I think, speaks to the difficulty of writing about tastes.  Even something that I thought was universal, sourness, is not necessarily obvious or the same for everyone.  You can probably say the same thing about other tastes and sensations: bitterness, for one, is received very differently by different people, as anyone who’s had tea with friends would know.

So, as one of my friends suggested today, I’m going to ask you this — what is sourness to you, specifically in tea?  Do you know what I mean when I say a tea is “sour”?  If you do, can you describe it, and if you don’t, what do you think I might mean?


Comments

What is sour? — 33 Comments

  1. Was thinking the other day that we should be able to describe a few sour tastes, or at least a scale.

    If you’ve ever tasted citric acid in concentration, it is sour, but not quite the same effect as tasting a lemon or sour candy – despite being one of the flavor components. Still different is ‘fermented sour’ like sour kimchi or fermented plum.

    There are three different kinds of sour I think about in tea:

    We often refer to fermented plum in aged oolong, sometimes accompanied by what I personally think is a pleasant kind of sour for tea to have. Puckery, but not leaving a weird taste in your mouth like citric acid, or overwhelming like fresh lemon/grapefruit or sour candy.

    There is also a slightly different sour taste associated with oolong that has taken on a bit of moisture during the aging process. Depending on the amount of spoiled, this can range from acceptable to downright vile. There is a tiny hint of this sometimes brewing TGY with a lot of newly broken leaves.

    Then there is something I first heard described by the host of this blog – a mild sour taste from ‘gu shu’ or ‘wild tree’ type puerh blends that are popular these days. My preference for this one is a lot lower than the ‘fermented plum’ aged oolong.

    • Hmm, did I say that?

      So you think of the different types of sour as being distinct — now, would you use different words to describe them?

  2. I think this problem won’t be solved for sourness. While everyone in the modern urban world grows up with the experience of crystalline salt and sugar on the tongue, there’s no single standard in our memories for pure, unadulterated sourness or bitterrness. And umami…!

      • Even before pure sugar and salt were widely available? Hmm, I’m not a taste archaeologist, though I’d love to meet one and have a long conversation. At the risk of repeating myself, my basic point is that, even though science can delineate distinct taste components by identifying their respective receptors, this doesn’t help people like us understand each other better unless we have experiences tasting things that stimulate only one of the – five? – receptor types at a time.

        • Ah, I see what you mean. I think you’re right — how we perceive flavours are very individualized and unless we’re sitting in the same room, drinking the same cup, the sensory experiences are bound to be different.

  3. For instance, when you talk about a pu erh turning sour in late infusions I think I know what it means – to me it’s like the sweet elements in a given taste run out of steam and the sour elements become overpowering. I understand “sour” to describe something unpleasant, unbalanced, while “fruity” would be a similar experience, but on the pleasant side.
    “Sour” is a relatively rough description to me, because there are so many varieties of it. For my personal tasting notes I sometimes use comparisons with common taste experiences to qualify it. Or the mouthfeel that goes with it.
    It’s always an interesting question to me why a taste is unpleasant – is it too strong, are balancing elements missing, does it bring up certain associations, is it accompanied by a certain mouthfeel … ?

    Martin

    • Can fruity be not sour? I think sometimes I use fruity without thinking of sourness. Apples, for example, can be loosely described as fruity but apples are usually low on the sourness scale.

      I think you are right on the balance issue — all sensations are good up to a certain point, beyond which it is unbalanced and unpleasant.

  4. I am doing my research on taste aesthetics at The Tea Institute at Penn State,

    The system the Institute uses to create flavor profiles for tea recognizes 4 (+ 1) basic flavors:
    Salty
    Sweet
    Bitter
    and Umami
    Within these basic flavors there are tonalities,
    ranging from High Tones, Mid Tones, Low Tones, and Base Tones.
    Thus, one can find the intersection between the two.

    For example, High Sweet is fruit, Mid Bitter is nuts & seeds, Low Umami is Smoked, and Base Salty is Mineral.
    Within each of the “notes” (such as the examples above), there are more specific examples such as citrus fruits, almonds, mesquite, and calcium respectively.

    Sour is also a basic flavor, but a more “complex” one because there is no such thing as pure sourness.
    All sours are acids; there is no difference between a measure of overall sourness and overall acidity.

    The way the Institute teaches our students to think about sourness is that sourness can be present or absent from any note, and in varying amounts.
    So if you think of fruity acidity, you may be thinking of citrus fruit. That may taste good in your tea.
    But, if you are tasting hints of sour meat, that might not be so present in your Shu…

    Looking forward to your commentary!

    All the Best,
    Jason M. Cohen

    • Thanks for your comment. It appears to me though that you’re merely adding complexity without actually adding specificity. For example, you mention how Base Salty is Mineral – but I neither know what Base Salty is, nor what Mineral is, in your definition, so you’re essentially using terms that I don’t know to define other terms that I don’t know. I, for example, wouldn’t categorize nuts and seeds as bitter. This is much like someone learning a new language using a dictionary, but every word in the definition needs to be looked up again, making the dictionary rather useless.

      The same goes for my original point, which is that sourness, as I use it, is hard to pin down, and my readers apparently don’t know what I mean, when I thought I was talking about something that is quite basic and commonplace. So, the difficult remains of trying to talk about flavours when the words we use to convey flavours are, in and of themselves, very transient and fluid. Which is why, generally speaking anyway, I don’t talk about flavours.

      • I agree that there is a certain level of complexity with the system used by the Institute.

        I disagree with you major point in the discussion, that the experience of flavors are so distinct to each individual that they cannot be compared.

        It may be helpful to think of this abstractly;
        color is a suitable example.

        Colors fall along a spectrum, and while there are no clear delineations for when one color ends and another begins, there is near universal agreement on what constitutes blue and what constitutes red.

        Even off of the primary colors, the majority will agree on the “specifics”. One can identify maroon v burgundy v scarlet.

        If this were not true, then we would not have names for these distinct colors. This is basic aesthetic theory.

        Now think of the primary colors as Notes, the shade as Tonality, and the specific colors as examples. You have the Institutes flavor analysis system.

        Finally,
        to address the argument that one may not be tasting what someone else is tasting, I respond “so?”.

        I don’t know how you perceive green, but I know that you perceive it in a consistent manor. Because we both individually perceive green consistently, I nor you will wake up tomorrow and begin calling green as red. Thus, we can both confidently talk about the “green” frog, or discuss the finer nuances of a shaded green painting.

        Taste works the same way. Are perceptions are consistent and thus comparable.

        I will say that there is a added layer of complexity due to the concept of “reference flavors” and memories of flavors. This is easy to work around by using a defined nomenclature for comparison; as the Institutes system has so far succeed in doing in our (unfinished) tests.

        Thank you for taking time to discuss this!

        All the Best,
        Jason M. Cohen

        • Colour is an interesting example. I think they illustrate the exact problem I have though. We have universal standards for colour because it’s easy to set them — all you need is a card with said colour painted on it (maroon, let’s say). It is easily verifiable, and as long as everyone agrees that that is maroon (and there are industry standards) then we’re fine.

          These names, however, are just that — names. They actually say nothing about how we actually see the colour, but rather, how certain colours are called. We can easily swap the name maroon for, say, acme, and from now on call what used to be maroon acme. It’ll be the same colour; it’ll just go by a different name.

          For people who have never seen maroon, however, or who don’t know the difference between maroon, scarlet, crimson, and the various other shades of red, maroon might just be “red”, and so will crimson, scarlet, etc. In fact, I’m pretty sure that if you showed someone the maroon, and asked “what colour is this?” most of the answers will be “red” and, quite likely, a few wrong shades of red. Some will answer correctly that it is maroon, but I’m pretty certain that will be a minority of the responses.

          This means that you have to learn the names for the colours in order to use them properly. Without learning them, they are basically useless as descriptive terms for the general public. Sure, those “in the know” will be able to use it effectively to communicate with each other, and that is how professionals do it, but the average lay person will probably get the shade wrong 8 out of 10 times, if not more. Some shades are more distinctive than others, making them easier to remember and learn, but it doesn’t mean that they’re not learned. This strikes me as what you’re doing with your friends – you share the same cup of tea and agree upon a set of terms to describe certain tastes common in tea. Therefore, you’ve agreed to a common vocabulary for those tastes, and can communicate using that particular vocabulary. For the rest of the world who has never learned your system, it is not very useful.

          That is also the difficulty with taste, in comparison with colours (vision). With visual descriptions, it is easy to parade a colour around and say “this is colour X” and have everyone agree upon it. When you have near universal agreement on a certain name, then it becomes meaningful and can be used widely for various purposes. In this instance, even people who are completely colourblind can learn colours. I have a friend who can’t see any colours, but can sometimes (not very accurately) tell different colours apart, because he’s learned to recognize the various shades of gray that he sees in life and associate them with different colours as others tell him what is what. So in his case, he can even use the vocabulary without actually being able to perceive it very well, because he has learned it and because it is near universal.

          Taste, however, is not transportable like that. We can’t ship a colour board of taste in the mail and set a standard that way, not easily anyway. Whereas you can share a cup with your friends and agree on a certain taste, those of us who are not there can hardly grasp what you mean by “acidic” versus “fruity” versus “puckery”. Even if you send me the tea, it’ll still come out differently for me based on the water I use, how I brew them, etc. Taste is also a combination of smell and taste, really, so it’s even more complex than that. Colours are very simple, in comparison.

          Wine writers have been able to forge a largely usable vocabulary among themselves, one that they can use with other wine enthusiasts to describe the smell and taste of a wine. I think this is, at least partly, because wine is a more stable product than tea. A cup of wine from the same batch, drunk in different parts of the world, will be mostly similar. If someone reviews a 2007 Rhone valley wine that sounds interesting, I can go to my local shop and buy a bottle and taste, more or less, the same thing the wine writer was talking about. Even then, most wine reviews are nonsensical for a lot of the lay population who don’t spend a lot of time drinking and reading about wines. With tea, the task is even more complicated.

          And the idea that six billion people can all taste the same thing is pretty much impossible — if there are colourblind people, there surely there must be people who are deficient in certain tastes. It is not easily detectable, because we have no way of discovering such differences, unlike colour, which is easily tested.

          Of course a common vocab will be useful; I’m just not sure how it is possible to achieve it.

        • Jason,

          You are approaching this as if senses can not be flawed even when they appear to be working normally. While the eyes tend to adjust faster because they are always taking in Data and recalabrating, there are times when eyes do not perceive certain colors as they should. Its what I call the Ski Goggle effect, you put on the orange ski goggles and everything looks off in color for awhile, but then after you wear them long enough you do not really notice the change and you can easily identify almost specifically certain colors in the same family even though you are using colored lenses. Then you take them off after a day full of skiing and now the colors seem off again, partially because your eyes had adjusted to the way things look with the orange goggles on.

          The problem with taste is, while the taste senses are always registering what is in your mouth, that is not always guaranteed to return to some stable state allowing you to recalibrate then go from there again. Have you ever noticed how certain things do not taste right after drinking or eating certain things. Like Orange Juice is disgusting after brushing your teeth. Well most people do something in their mouth eat or drink something, and assume because they are not realizing they are tasting it two hours later that their mouth has returned to the exact same state as it was before they did that. Not to mention so much of taste is smell the condition of your breath plays a huge role in how your tastes are working at that particular time.

          I have learned when you describe the flavor of something, it at best describes the flavor based on the condition of your mouth at that particular time. Now I never used to quite believe this whole pairing idea of pairing certain foods with certain drinks, but when viewed from this light it makes so much more sense. It uniformly sets everyone’s palate so close to the same area by having chocolate or cheese or what have you, so they all experience the beverage in a similar fashion, and it is usually such a choice that it sets their palate up so they taste certain aspects of the drink that people in general seem to find more attractive.

          So in short I am with Marshal on this, because while it is easier to decide on some basic tastes most of which are quite cutting and apparent, sweet, salty, bitter, when we start to describe more complex flavors it really comes into play what we had for our last meal, or if we stood in a room full of smoke, etc.

          Adam.

          • Dear MarshalN and Adam,

            The individuals involved in Institute tastings have a 2 1/2 hour cut off for any “flavor consumption”; so no food, gum, or drinks before the tasting, and certain foods are banned for the day (coconut, avocado, banana, etc.).
            We start off all tastings with a glass of the water we will be brewing with.

            I agree with you that most people could not tell the difference between shades of colors or identify specific flavors.

            I agree with you that “a rose by any other name would smell just as sweet”; that names are only a social construct.

            Yet names are necessary for discussion and comparison.

            It is wrong to assume that there is a universal standard for color. The oft quote tribe in the Amazon that does not differentiate between blue and green is a prime example.
            The names of all colors, just as tastes, must be “learned”.

            In cultural anthropology we call this a reference color or a reference flavor.

            Reference flavors are cultural but are relatively easy to learn. Reference flavors are also dynamic, someone who has had a lychee for the first time my start correlating the flavor with certain Oolongs. You discuss this yourself in a comment below on chenpi.

            To move from colors to tastes as our examples, we could think of many american reference flavors in ice cream:
            vanilla, chocolate, strawberry, and coffee among others.

            While the quality and amount of flavor may change between brands, there isn’t any surprise when you order one of these, and you would immediately know if you were given the wrong ice cream.

            To clarify, there are only 5 tastes (salt, sweet, bitter, Umami, and Sour). Any nuance in these flavors, and all complicated flavors such as vanilla, chocolate, strawberry, and coffee, come from the presence of volatile aromatic compounds. I have been including aromas under taste in this discussion.

            The Institutes Flavor Analysis System, that I have been developing, uses “large spectrum” reference flavors in order to allow individuals to create flavor profiles.

            “Large spectrum” reference flavors are categories such as fruits, herbs, spices, and dairy. They are large categories that though diverse are “universally” agreed on. These “Large spectrum” reference flavors have all been correlated with specific chemical compounds, many of which can be re-produced in the laboratory; just think of all the artificial flavorings in food!

            This leads us to the point where I will claim that there exists a standard for flavor, just as there exists a standard for color. Colors are certain wavelengths stimulating your optic nerve through receptors. Tastes are a combination of the stimulation of gustatory calyculi on your tongue and aromatic compounds entering your nasal cavity, all of which are caused by specific chemical compounds. Vanilla (vanillin, 4-hydroxy-3-methoxybenzaldehyde) and indole (responsible for the floral aroma in Sheng Pu’er) will taste and smell the same tomorrow as they so today.

            In fact, some schools of wine actually train their students with flavor extracts so that they will all use the same reference flavors. The Institute does not do this as I prefer my students to build their lexicons naturally.

            To conclude, I believe and hope to prove that flavors can be objectively analyzed and discussed. My research with the Institute (to be published in about a year) may or may not achieve this.

            Thank you for taking time to discuss this. I have found this conversation an informative critique on the aesthetics of flavor.

            All the Best,
            Jason M. Cohen

          • The fact of the matter is that different people do literally taste things differently – for example, the supertaster / taster / non-taster thing. I always assumed that I’d be a taster, because I’m somewhat sensitive to bitter and astringent tastes, but surprisingly, I’m not. Aside from physical differences, our subjective experience of taste can vary quite a bit from session to session and from person to person.

            I think it’s certainly useful to train one’s palate, and I do think that you can “learn” a vocabulary to express some things about the taste of something. At the same time, I think a “scientific” approach to taste can only go so far. After all, there’s a reason we refer to someone’s “taste” in regards to so many things (music, movies, etc.).

            As far as sour, I do notice a feeling on the front of my tongue and a slight metallic note with a lot of sour teas, aged oolongs specifically. I do perceive different “types” of sour in both tea and food, whether or not they are all the same “sour” at the heart of things.

  5. I believe that every person would have a different opinion on this subject. I definitely think this is an interesting poll so here is my two cents I can describe two types of sour. The first being citrus sour that salivating pucker you get when you bite into a lemon or lime. The second being the sourness of something in the refrigerator about to go bad and if you ask me to choose please don’t give me the thing in the refrigerator and spare my stomach. I think also that in the subject of tea and sourness with all the sweeteners on the market the true sourness is more than likely masked in today’s society. Which skews our views on this subject.

    • Right, so the question is how to deal with the differences among individuals, and more importantly, how to talk about them intelligently.

      • Well it seems that the consensus is everyone has a different perspective on what sour is. With that said discussing the topic intelligently would be totally opinionated. Each individual could describe it to their taste. How interesting would it be for you to pick a tea that you thought was sour and suggest it to your friends family and blog followers and ask them to describe it. You could also do this for many teas. Looking forward to see what happens!

  6. Here are some elements to help…
    i’m not saying this is the holy bible or anything like that… just some toughts…
    if we want to describe in a very easy way what is a taste then we have to make comaraisons with what everyone nows. with something available to test by everyone. therefor here some hint.

    Acidic = lemon
    Sour = vinager
    Bitter = pure chocolate or coffee
    Astringency = white side of a banana peel or some red wine.

    Now the problem is that a lemon is acidic (not sour) and sweet … but main compoound will be acidic.

    Hope this helps… and this is just a tought.

      • And I’ve had balsamic vinegars that taste very sweet.

        Perhaps this issue would best be resolved by comparing the innumerable tastes associated with various teas to specific flavors, rather than adjectives that can be open to interpretations.

        For instance, it may be better to compare the sweet flavor of a tea to a specific fruit (or specifically say it is “sweet like a fruit”), rather than just say it is “sweet”. It may be better to specifically state what the sour taste reminds one of, rather than just say it tastes “sour”.

        Very interesting topic and discussion to say the least …

        • Good point — something more descriptive can be useful, although we’re still running into the problem of using words to describe taste, which can be pretty subjective. Case in point — when I say something is “plummy”, I know what I’m talking about, but what if someone hasn’t had a plum before? Or, we often use “chenpi” as a way to describe the taste of an older oolong, and chenpi is something Chinese often eat, so any Chinese would know what it is. However, most Westerners have never seen chenpi, never mind eating it.

          • You’re right. However I feel that this dilemma is inevitable, and unavoidable.

            There will always be someone who has never experienced food ‘x’. I would be the person who has absolutely zero idea what ‘chenpi’ tastes like, so that description of a tea would be useless to me. And yet, if I was interested in trying/buying that particular tea, I would absolutely ask you to further describe the tea for me … perhaps until you named a food/taste that I have experienced.

            I can’t see any way around this issue. However, I do think it can easily be overcome by further communication (when required).

      • Ok so let me rephrase this

        White vinager is sour

        Balsamic will be like a lemon, sweet and acidic with more sweetness than sourness.

        This is the point of having a global lexicon.
        The information i give here is based on my knowledge of tasting.
        I work for a large coffee compagny and we use this kind of international lexicon of tasting.
        When you speak of flavours, tastes or what you smell you should always refer to a standard lexicon. This kind of “books” exist they are references.
        Just like a dictionary for words, to know the exact definition of what’s a chair, you should have an exact definition of what are these tastes ect. hense the reference guidebooks.

        At contrary of what people generally think, tastes are not different for everyone. But the fact you like or dislike a taste is different.
        Some factors like somking, stress or other elements may interfer with our tasting abilities. but we all tast or smell basically the same, or are able to do so…

        For the sweet like or sourt like you tottally right… the more detailed you are the more specific you are the more chances you have to be understood.
        it has the sweetness of this or this kinf of fruit… indeed… that refers to the intensity of sweetness…

        Well just some more thoughts…

        cheers

        • “At contrary of what people generally think, tastes are not different for everyone. But the fact you like or dislike a taste is different.”

          I absolutely agree with this.

        • Is that true though? I mean, I know, hypothetically, what bitterness is in tea. However, I no longer really taste it — I have a sense it’s there, sometimes, when I drink something particularly bitter, but only because I’m aware of what it should be, rather than really sensing the bitterness. I also know what it is because sometimes my tea friends who are not as used to bitterness will let me know.

          So while I agree that we more or less taste things the same way, they are clearly not identical. There are also the problems that even though we may, physically, feel the taste somehow, it is not something that necessarily registers as a cup of tea hits the tongue. More experienced tasters will obviously be better at detecting things than inexperienced tasters. So…. sensing something and being aware of it is once again an issue.

  7. I thought I would add another layer to the appreciation of sour or any of the basic flavours in Chinese five phase theory and applied in herbal medicine. Herbs are described as being, let’s say, sour but that doesn’t mean that the herb itself actually ‘tastes’ sour. The idea of it being sour is more that from an energetic perspective in that it has an effect on the body that embodies the movement that sourness creates. Such a movement in the case of sour is that of an inward movement, the opposite of a dispersing outward movement. Many herbs that astringe urination, sweating and stop leaky bowels are do so from there sour flavour characteristic, but not all ‘taste’ sour (don’t get me wrong, some are extremely sour in taste as well!).

    So, just a thought, if a tea doesn’t taste sour but still gives your mouth a reaction you would associate after drinking something sour then you could consider it to be energetically sour. Just as you would consider a tea that produces a light sweat to be 辛 or pungent/acrid/spicy even if it didn’t taste so.

  8. Hello. I wonder if you can help me out.

    I purchased some pu-erh tea from an internet site: Rishi.

    I didn’t know that you had to rinse pu-erh first and so I have been drinking it without washing it — just steeping for about five minutes and drinking. What would happen to me physically if I continued this practice, i.e., never rinsing the tea before drinking it? The tea was loose and one type came in little ‘coins’.

    Thanks,
    – Paul

    • Well, millions of tea drinkers drink their tea without rinsing. It won’t kill you, although you’ll get better results if you do.

  9. I got two cakes of pu-erh in the mail yesterday and this batch was SOUR.

    As in SOUR, I mean “LEMONS SOUR”. If you know what lemons taste like — there you go.

    Not exactly “citrus” though… In my opinion, something with a little orange or lemon zest is “citrus”… swigging a half a cup of lemon juice is not quite “citrus”. This one has more like a sour, lemony green leaf taste.

    The tea was an inexpensive, Raw Spring 2011 Yi Wu from the Cai Zhe factory. BIG ancient leaves pressed into a Bing Cha.

    I see “floral”, “fruity”, “sweet” etc. mentioned a lot when describing pu but rarely SOUR… and this tea is it.

    I’m not sure that I really “like” it. It’s interesting but too overwhelming at this point. Probably not something that most who favor young puerh would find appealing — I’m hoping the sourness ages out.

    With the old leaves and the high level of acidity in this one, I’m thinking it should be an interesting candidate for long term aging though.

    If anyone else has any experience with aging SOUR cakes, please let us know. Info seems to be kind of limited.

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