The Power of the Willat Effect: Rinsed versus Unrinsed Tea

During my last visit to New York I bought a new black tea. I started drinking it a few weeks ago. I brewed it various ways (different amounts of tea, different steeping times, etc.) but had a hard time telling which way was best. This morning I decided I would learn how to¬† brew it by making paired comparisons (two cups of tea made the same way at the same time except for one difference). The fascinating thing, as I’ve said, about these side-by-side comparisons is that they produce hedonic changes. They change how much you like this or that. I call this the Willat Effect after my friend Carl Willat who caused me to notice it.

This morning I made two cups of the new tea. The two cups were brewed the same except in one case I “rinsed” the tea before brewing. Rinsing means I poured a bit of hot water on it and quickly got rid of the hot water. Rinsing tea removes from the final product whatever is transferred from the tea to the hot water in the first few seconds. In China, rinsing tea is common; in the United States, very rare.

I tasted the two cups (rinsed and unrinsed) side by side. The rinsed tea tasted much better. The unrinsed tea had something weird about it. Ugh, I thought, I can’t drink this. I threw out the unrinsed tea. Over the previous few weeks, I had happily drunk the new tea unrinsed many times. Now I found it repulsive.

11 Responses to “The Power of the Willat Effect: Rinsed versus Unrinsed Tea”

  1. Sean Says:

    Wouldn’t you want someone else to prepare this for you to make it a blind side-by-side test? Otherwise you could spend the rest of your life rinsing tea for the placebo effects.

    Seth: I have found the effect to occur whether or not I prepare the drinks.

  2. Adam Says:


    My Chinese mother-in-law tells me that if there are bubbles on the top of my tea, I should blow the bubbles to the edge & then pour them off. I don’t know if this is widely practiced, but she seems to have learned it from her father.

    Sometimes I do it if I notice, but I’ve never done a side-by-side comparison to see if it makes any difference in taste. Could these 2 be linked?

  3. Gayle Says:

    Hmmm… I wonder if this would work with coffee grounds, too…

  4. Drewfus Says:

    Seth, what happens when the teas are tasted blind, in regards to not knowing how their preparations differ?

    “Over the previous few weeks, I had happily drunk the new tea unrinsed many times. Now I found it repulsive.”

    Is that purely because of the taste, or because you know the tea has been unrinsed, and are reacting based on that higher level knowledge, or both?

    Seth: If it had been done blind, I am sure the results would have been the same. To answer your second question: Purely because of the taste. There is nothing inherently wrong with unrinsed tea.

  5. Kirk Says:

    I agree, rinsing produces a better flavor. The rinsed tea has a rounder and cleaner taste and the sharp edges have been removed.

    My bake-off compared .5 of an ounce of an organic Assam, using 4 oz. of water, steeped for 2 minutes. After 3 rounds of tasting, I poured the unrinsed tea down the drain.

  6. Jon K Says:

    I’m pretty sure that rinsing tea removes or greatly reduces the amount of caffeine present. Whether this is directly related to the change in taste, I don’t know. But it is interesting because many people drink tea (especially black tea) at least partially for the caffeine.

  7. Txomin Says:

    Sure. Weak tea is good.

  8. Greg Says:

    The Willat effect is real and it is very dangerous. Last year I did a few side-by-side taste tests with the Keurig coffee machine at my workplace. Now I can’t stand to drink any of it and can only enjoy direct trade hipster coffee that is roasted in Brooklyn.

  9. Drewfus Says:

    Seth, thanks for the reply. I’ve more or less asked the same question as Sean (above) so i’m glad i didn’t get into trouble for that. Regardless, this (Willat) effect is important, so i’ve started testing on myself. With green tea, i noticed a small but worthwhile improvement. The rinsed tea has a cleaner taste – especially the aftertaste. I’m slightly concerned that i’m imagining this, so will organize some blind testing. Maybe using a microwave oven to spin the tea cups, so i forget which is which!

    Seth: there is an easy test for whether you are imagining the difference. use identical tea cups. Put little labels on the bottom of the tea cups (e.g., R and U). Pour rinsed tea into the R cup and unrinsed tea into the U cup. then close your eyes and switch them a bunch of times (not counting how many times). you will soon lose track. Then open your eyes and do the comparative tasting. decide which cup holds the rinsed tea and see if the label on the bottom of the tea cup shows you are right.

  10. Alex Chernavsky Says:

    I’d like to propose a phenomenon which I’ll call the reverse-Willat effect. On a couple of occasions, I did side-by-side comparisons and found that — contrary to my expectations — the samples tasted remarkably similar.

  11. Jenny Says:

    The evening after I read this, I was chatting to 2 Chinese friends (here in England) about this. They were amazed because they always ‘rinse’ their tea. So I tried it, and prefer it, finding it less bitter. I haven’t tried it with T-bag tea yet, only loose tea.

    One of the ladies also told me that, having been an avid coffee drinker (8 cups a day), she gave up coffee for 6 months, and now finds that all coffee has an after-taste of peppermint – which she doesn’t like.