Is Cream Down (冷後渾) a sign of better black tea?

IMG_3334

Cream down (milk down, or tea cream in some literatures) is an effect of precipitate formed after tea cools down.  It usually happens in black tea or highly oxidized oolong tea.  Some assert it is a sign of superior quality.  However, there are also some literatures discussing how to eliminate cream down effect on ice tea (or beverage tea, usually cheap and low-qualitied in nature) since consumers prefer clean and crystal tea. These controvertial findings make me doubt if cream down effect is proper measurement of tea quality.

冷後渾是一種茶溫下降之後發生的沉澱現象,常出現在紅茶或高發酵的烏龍茶。有人宣稱 (越來越多人) 冷後混是高級紅茶的象徵。然而,很有趣的是,另外有一些文獻卻是研究如何消除茶飲料中的冷後渾現象 (茶飲料通常使用低級、低價的茶),因為消費者比較喜歡乾淨清澈的茶湯。這些悖論的發現,讓我開始懷疑冷後渾是否為判斷茶品質的標準?

Below is little experiment I did to test if cream down effect could happen in cheap tea (or low quality tea).

底下是我做的一個小小不嚴謹實驗,用來試試看是否低價(低品質)茶也會發生冷後渾現象?

  • A Set: Brew a cheap black tea by a normal method (5 gram tea/ 150ml boiling water for 3 minutes), and put into a refrigerator to cool down to 5°C. (A組: 5公克茶配150ml滾水,泡3分鐘,放入冰箱將茶溫降至5°C)
  • B Set: Brew the same cheap black tea by alternative  method (10 gram tea/ 150ml boiling water for 5 minutes), and put into a refrigerator to cool down to 5°C.(B組: 10公克茶配150ml滾水,泡5分鐘,放入冰箱將茶溫降至5°C)
  • The result: B set has significant cream down effect while A set has little. (結果: B組有明顯的冷後渾現象,A組不明顯)

I think it’s obviously cream down effect does not only happens in high qaulity tea.  You could generate the same result with low quality tea if the concentration of tea is high enough.

我想很明顯的是冷後渾現象不只是高品質查的專利。只要茶的濃度夠高,你也可以做出冷後渾。

After discussion with some friends and searching literatures online, below is what I have found from literrature on PubMed 

在跟一些朋友討論以及在網路上的搜尋,下面是我在PubMed上找到的文獻

  •  A higher tea concentration leads to earlier onset of creaming and larger particle. (較高的茶濃度有助於乳化現象的提早以及大量的形成)
  • Theaflavin, caffeine and calcium are major factors of forming tea cream.(茶黃質、咖啡鹼以及鈣質是形成乳化現象的三種要素)
  • Tea creaming may be reduced by increasing the solubility of the polyphenols or by removing calcium. (增加茶多酚的濃度,或是移除鈣質有助於減少乳化現象)

My Conclusion

我的結論

Since tea cream is originated by three factors: Theaflavin, caffeine and calcium.  One could get suffcicient tea cream by increasing the theaflavin& caffeine in tea or adding calcium in water.  Maybe I should rephrase the question:

既然冷後渾是由茶黃質、咖啡鹼以及鈣質三要素構成,增加茶裡的茶黃質與咖啡鹼,或在水中加入鈣質,即可得到足夠的茶乳化現象。或許,我們應該這樣問這個問題

Is higher theaflavin, caffeine and calcium make a better tea? And if yes? How is it to with to enhence our tasting experience in terms of aroma, flavor and balance of tea…ect?.

How do you think?

是否越多的茶黃質、咖啡鹼,鈣質的含量越多,茶的品質就越好?如果是,這些元素如何表現在品茶的方面,如茶香、茶滋,茶整體的平衡…等等。

各位,您認為呢?

Advertisements

3 thoughts on “Is Cream Down (冷後渾) a sign of better black tea?

  1. It would be very enlightening if someone can describe the methods that the commercial beverage companies (Snapple, Lipton, etc.) to prevent the cream-down effect.

  2. Very interesting… I had never thought of this! Is the amount of calcium significant? (probably not, but compared to cheaper teas?) What is theaflavin? I am curious to hear more! 🙂

  3. Creaming down is the effect of oxidation of the constituent properties of the brew: flavinols, amino acids, etc.The higher the flavour/body enhancing ingredients in the tea brew, the greater is the creaming. So a high quality brew creams down more than a low quality brew.
    If glad-wrap is stretched across the surface of the tasting cup to exclude oxygen, no creaming takes place.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s