On our trip out to Doke Tea Farm in Bihar, we picked some leaves that were transported back to Siliguri. They get left out for 18 hours then frozen for no fewer than 18 hours. They are then rolled and dried using a very innovative process involving a hair dryer and a wooden box lined with metal. This has got to be one of the most innovative ways I have ever seen tea made. Bravo!
Jason McDonald Linda Gaylard, yes it is frozen. We are assuming the science behind it is that during the rolling, the goal is the break the cell walls. Since water expands when frozen and makes jagged water crystals, the freezing shatters the cell walls. There is a particular timeframe of when to freeze and how long to freeze. It was mentioned that if it is not frozen long enough, it does not turn out right. It was an interesting process but makes great tea. Very innovative.
Linda Gaylard Indeed. I wonder if freezing also creates more sugars – similar to icewine, where the starches are converted to sugar as the temperatures become frigid.
Jason McDonald They may. It is called distatic fermentation but you need pytalin (an enzyme) already present for that to happen. I do not know if tea leaves contain that enzyme. Maybe Nigel Melican can help on that question. Either way, it makes for an interesting process and lovely tea. I am a big fan of a strong flavorful tea.
Nigel Melican Polyphenoloxidase enzyme is not destroyed by freezing and the 100% cell disruption by ice crystals ensures every molecule of catechin substrate “sses” some enzyme thus total oxidation and strong black tea. The freeze process was used in Lyons Tea factory in Malawi in the ’30s – no surprise then that Lyons Tea and Lyons Ice Cream had the same parent company – however it was abandoned in ’70’s due to higher cost of production. I have used the process occasionally for “specials” so good to see it being put to good use by Doke Tea.
Jason McDonald So that about answers it. Elyse M Petersen, Michael Petersen, Tico Aran, Rie Tulali, Phil Tea Holmans, Rajiv Lochan, Neha Lochan, and Vivek Lochan, that answers what is going on there.
Jason McDonald That batch was made sugary sweet because I hand rolled it. LOL (true story).
Images Courtesy of Rajiv Lochan, of Lochan Tea.
It is so interesting to me that tea can be frozen during its processing. That it was discovered in the 30’s intrigues me. I can easily see how it was an expensive process but it is curious that no one experimented with it again before now. Although I am a purist in general, I’m not opposed to this type of non chemical experimentation. If it creates a stronger more robust tea, that’s a good thing. It reminds me of blueberries. Given its touch skin, by freezing the berries before putting them into a blender for a smoothie, it provides significantly more availability of antioxidants once the cell wall is broken, as it does with tea apparently.
Thanks for this insightful post Rajiv.