Wednesday, January 31, 2024

A controversy over adding lemon and salt to tea


Facebook tea groups are wrapping up a phase of discussion about the theme of adding lemon or salt to tea, a recommendation from a recent book on tea.

This relates to Steeped: The Chemistry of Tea, by Michelle Francl. Basically salt is supposed to offset astringency and lemon reduces tea scum or cloudiness caused by calcium compounds. Here are the claims, cited in an article reviewing that book content (which I guess could contain some error in summary, to be fair to the original author):


Francl’s pro tips for the perfect brew are:

Adding a pinch of salt – the sodium ion in salt blocks the chemical mechanism that makes tea taste bitter.

Steeping teabags quickly but with plenty of dunking and squeezing – to reduce the sour-tasting tannins created by caffeine dissolving slowly in water.

Decaffeinated tea can be made by steeping a teabag for 30 seconds, removing it and discarding the liquid, then adding fresh water and rebrewing for five minutes.

A small squeeze of lemon juice can remove the “scum” that sometimes appears on the surface of the drink, which is formed from chemical elements in the tea and water….


There are two sets of problems with these ideas: one is that they make no sense, presented in this form, and the other is that what they really probably refer to that could be accurate, after some editing and adjustment, is still problematic.

It’s possible that the first claim is that when you taste salt you also notice less bitterness. It could instead relate to a claim that sodium is going to offset extraction of compounds resulting in astringency, which is a mouthfeel effect that is often confused with bitterness.  Bitterness is a flavor, not a mouthfeel aspect, but people conflate the two. It doesn’t clearly say that; that’s only one possible interpretation of this summary. 

Caffeine really does taste bitter, as some other medications do, like aspirin, but surely salt isn’t going to offset caffeine extraction. Salt doesn’t seem likely to affect tannin extraction either, but I suppose I wouldn’t know if it did. In the following point, related to caffeine, tannins aren’t created by caffeine, and again it seems doubtful that caffeine could affect tannin extraction.  Again the feel effect of tannins is more often misinterpreted as bitterness, not sourness.

A short tangent can help place that first possible interpretation.  I add salt to masala chai (spiced black tea) to increase flavor depth, which happens even without noticeable salty flavor, as can occur with food.  Once out with family to a Mongolian grill place a niece and I added salt to our dishes that ended up way too spicy.  Salt doesn’t decrease the experience of spice, the heat, but it can help spicy food flavors balance better and make more sense.  This may be the claim here, that the salt isn’t blocking any compound extraction, or shifting feel effect, but that the overall flavor balance might seem more positive when shifted a little, potentially even without the tea tasting salty.  Maybe.

That decaffeination hack listed has been debunked over and over; this study’s caffeine extraction rate testing results work as good a summary review as any to show why:


30 seconds: 9% caffeine removal

1 minute: 18% caffeine removal


So no, removing 9% of the caffeine isn’t going to help much, and you're probably removing 9% of the flavor along with it. Beyond these errors some main points work, to a limited degree, which I’ll move on to critiquing.

One problem with these claims goes back to why a tea would be astringent or would have a scum on it in the first place. It’s talking about brewing low quality, ground material, tea-bag black tea, which is very astringent for a few different reasons.

The form of the leaf is a main input; whole leaf tea is less astringent, because compounds extract differently in ground material (tannins, to use the informal designation; let’s get back to what those really are shortly). The more you chop or grind the material the faster it brews, and the more overall flavor is extracted, just not necessarily the most positive flavor or feel related compounds.  This is why tea bags that contain 2 or 2 1/2 grams of tea leaf material are quite chopped or even ground up, to get more out of a little leaf content, which brews faster. So you can use better quality, more whole-leaf tea instead and skip the salt, but it’s more expensive, and you would need to use a bit more leaf.


a Ceylon (Sri Lankan tea) tea bag I cut open awhile back.



It doesn’t add much to what I’ve just expressed but lets consider what tannins even are, in relation to some of the flavor compounds being discussed, from this Tea Epicure source:


There are an estimated 30,000 polyphenolic compounds in tea.There are several known categories within polyphenols…

Within the flavonoid group are flavanols, flavonols, flavones, isoflavones, and anthocyanins. Flavanols (short for flavan-3-ols) are the most prevalent and thus the most studied. Flavanols are often referred to as tannins or catechins. 

The major flavanols in tea are: catechin (C), epicatechin (EC), epicatechin gallate (ECG), gallocatechin (GC), epigallocatechin (EGC), and epigallocatechin gallate (EGCG). EGCG is the most active of the catechins, and this flavanol is often the subject of studies regarding tea antioxidants.

Flavanols are converted to theaflavins and thearubigins during oxidation. They are the compounds responsible for the dark color and robust flavors that are present in oxidized teas…


The same kind of theme repeats with adding lemon. If you use water very high in calcium compounds, which is not so unusual for a lot of water sources, a light scum can form on the top of your tea, from polyphenols in the tea interacting with those calcium compounds. Lemon juice can clear that up. Or passing the water through a charcoal filter might help, removing some of the calcium compounds instead, before they combine with brewed tea and form a scum. 

“Tea enthusiasts” often use some special water version, bottled spring water from an ideal mineral profile source, or they’ll treat water to strip all the minerals, reverse osmosis filter it, and re-add an optimum mineral blend. All that might be going a bit far; in most cases using filtered tap water is fine for a decent outcome.  The extra level of concern seems to relate to optimizing outcome from a much better quality range of tea, the opposite extreme.


So in conclusion, no, salt and lemon have no place in tea. 


Or if you really want to use cheap tea bags to make tea, and brew it with relatively unsuitable high calcium content water, then sure, add those things. It’s your tea; it’s up to you.

If the goal is to experience above average quality tea that changes things, but that’s not everyone’s goal. Lipton or Great Value tea bags are really cheap, and easy to prepare, and if you add milk and sugar to that tea it can be ok. Or sugar and lemon, I guess; I don’t think it’s going to work to add both lemon and milk, since drinking curdled milk in tea won’t be pleasant. It’s just nothing like what tea enthusiasts drink.  

Most of the time, at least; I’ll drink Lipton sometimes at our office, because I’m only in there once a week after work from home was instituted.  Dilmah is better but they usually stock Lipton there.  There probably is no standard example of a tea enthusiast, so I couldn't possibly be one, but the generality of not using tea bag tea still holds up.


this meme breakdown makes for a long story


It’s too long a subject to treat as a short tangent here but pleasantness of the tea, flavor character and such, is only one part of range of concerns. Tea enthusiasts tend to take up the idea that more natural grown tea could be healthier, from forest or more natural growing condition sources, versus standard plantation teas, which are potentially grown with more pesticide input. Maybe it works out like that.  My guess is that Lipton is safe enough, but once you switch over to the lowest cost bulk sources from Chinese or Indian markets you are taking some real risk.

The same astringency that is a concern for “bitterness” input can also lead to stomach problems, for some. I wrote about this concern awhile back related to a co-worker needing to quit tea due to stomach impact.

The short version of that writing is that it will probably be necessary to drop out drinking matcha, black tea, green tea, and sheng pu’er entirely once these problems have already developed. Prior to experiencing damage to your stomach eating food before drinking any tea could protect you, at a guess most effectively if that food contains both complex carbohydrates and fat.  Eating just fruit doesn't seem to help, based on my experience. 

There are other types of tea that are milder than these, oolongs or white teas, and routinely alternating the types of tea that you drink could help.  Drinking more whole leaf tea would be better.  Once you already have a problem switching to shu pu’er could help, or going off tea entirely for a long period of time.

Let’s get back to the starting point and think all this through one more step: who is going to be interested enough in tea to buy and read a book about the subject, and then also prepare it from Lipton or Great Value tea bags?


Vietnamese black tea, the last black tea I bought a few months ago



whole leaf tea and CTC tea (from an early blog post, before phone camera quality had improved)



I would assume that this “better quality” tea is a familiar subject to anyone reading my blog posts or Quora answers, but in case it’s not this post covered more on that divide.


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