Freezing henna paste = Instant(ish) dye release?

[diverbel]

Usually if you use boiling water you get instant dye release, but you also get faster demise of the dye release and the color may not last, actually fade a bit. I use hot black tea at the temperature that it is hot, but not uncomfortable, kinda like really warm bath temp. I wait till I just start getting dye release, then I put it in a ziplock, squish it flat and freeze. The color I am getting is almost twice as intense as nonfrozen henna.

[jackie_brown]

I usually prepare henna when i'm at home (on saturday or sunday), because i have time to wait until dye release (let it oxidized for 8/9 hours) then freeze.
This way i only have to take it from the fridge on evening and it's ready to be applied the day after (fully oxidized and at room temperature) at lunch or in first afternoon

[Tisiloves]

I think it also depends on how long you leave it on for. IIRC one of the members on here mixes their henna and applies it immediately and then leaves it on overnight, so it starts dye releases on their head.

[cthulhuapproved]

From what I can gather, the dye release process isn't actually a chemical reaction, so freezing/cooling it won't necessarily slow it down. The dye molecules (lawsone) already exist in the henna plant's cells, so it's just an issue of getting them out of the cells and into the paste (and, thus, into your hair!). I almost always freeze mine immediately after mixing with tepid water or chamomile tea, and I get crazy dark stains every time---and I only leave it on my head for ~2 hrs. The 'skin test' leaves a significant stain on my wrist immediately after the henna thaws as well, which, to me, would indicate that the dye release has indeed already happened prior to application.

I remember someone else once suggesting that it could be due to the freezing process breaking up the cell wall, thereby releasing the dye molecule into the paste. To me, this seems like the most plausible explanation---consider a fresh blueberry: when first picked, it generally has only a blue skin and a yellow/green flesh inside, but if you freeze it, suddenly it's a gooey, dark purple-blue blob capable of staining everything within its reach. I know that this in particular is due to the expansive property of water as it freezes, so it doesn't seem like much of a stretch of the imagination that this could be the same mechanism responsible for getting henna to dye release through freezing only.

Or, at least, that's my semi-nerdy .

[akilina]

Last time I mixed henna I mixed it in warmish water and let it sit maybe for a few hours...maybe less I can't even remember and then I just threw it in the freezer. It has been maybe a week since then and I plan to use this henna sometime this coming week. In the past I have froze henna after letting it "get ready" for about 12 hours with even better stain after freezing-thawing. I hope this mix comes out fine...I have been sort of nervous about it

[cthulhuapproved]

I can only speak for myself as a..."frozen paste advocate," for lack of better phrasing, but I definitely agree that the time from mixing to actual freezing could very well account for the dye release when doing this (as opposed to my other 'hypothesis'). What I find confusing, though, is the reports of those who have left henna in the fridge to dye release, and have found that it can take days. This seems to suggest that it would require a similar amount of time sitting in the freezer, pre-freezing, for it to release enough to be usable.

However, in my experience, this is not the case. I actually divide my batches up into smaller containers than I mix them in specifically to get them to freeze in a reasonably quick time frame, and they are ready to go the moment they thaw enough to be workable, as evidenced by the prominent stain left on my wrist at that point. (Actually, I'm prone to impatience and there are sometimes still some frozen chunks in the mix when I try to apply it, if that helps to describe how cold it still is at this point.) The next time I mix up a batch, I think I will put half in the fridge and half in the freezer, and then compare the two after the freezer portion has thawed. If it is true that the paste is just dye-releasing before it has a chance to freeze, then it would stand to reason that the paste in the fridge should provide an equal amount of staining.



Either way, though, the main reason why I appreciate this method so much is the convenience---since I often have a hectic schedule, not having to worry about when the paste will be ready (or whether it will demise before I get a chance to use it) is reason enough for me to continue doing this, regardless of lack of legit scientific evidence! Not to mention, it only took four or five ~2hr applications prepared this way to get my hair to my desired point of near-saturation. So I'm pretty inclined to just chalk it up as "if it works, it works!" and carry on accordingly!

[cmg]

If it works, it works! Absolutely

But for the sake of understanding and learning from it, how exactly do you prepare your mixes? Have you ever done a batch and compared an unfrozen portion with a frozen one etc.?

/ CMG

[cthulhuapproved]

If it works, it works! Absolutely

But for the sake of understanding and learning from it, how exactly do you prepare your mixes? Have you ever done a batch and compared an unfrozen portion with a frozen one etc.?

/ CMG

It's really a pretty unceremonious process: I brew some chamomile tea and then I usually wander away and forget about it for awhile. When I finally add it to the henna powder, it's usually a little warmer than room temperature, but not what I'd consider 'hot' by any stretch. Then I just mix the two together in a large bowl and then separate it into separate smaller containers, which go immediately into the freezer. (The original purpose of this division was simply because I didn't have enough space in the freezer at the time for the actual mixing bowl. )

That usually takes place the night before I plan to henna, so the following morning I take however much out that I need, and leave it on the counter until it is thawed. If I'm home for it, I stir them frequently to keep the center from remaining frozen while the outside thaws. Then I just put it straight on, leave it for 2 hours or so, and rinse. Overall, pretty unexciting!

The first time I tried freezing it was definitely just an experiment---I had noticed that the general consensus seemed to be that, if leftover henna paste was frozen and used later, it typically stained better afterward. Then I read about someone supposedly getting dye release directly from freezing, so the next time I hennaed I tried it out, and since it was crazy convenient and actually worked, I just kept on doing it! Of course, I've only been doing this for a few months, so it could very well turn out that something else is going on that I'm just unaware of, or that there is a magical leprechaun inside my freezer secretly infusing my paste with mysterious leprechaun hair color...

I haven't tried freezing part of a batch and comparing it to an unfrozen portion yet, but I plan on trying it out this summer!

[cmg]

Thanks, cthulhuapproved!

...so it could very well turn out that something else is going on that I'm just unaware of, or that there is a magical leprechaun inside my freezer secretly infusing my paste with mysterious leprechaun hair color...

Thats it!

For now I have a hard time figuring out what really happens during the whole process, including freezing. There seem to be a number of conflicting chemical processes at play here. It also seems noone has done any scientific experimenting about this.

Maybe I should do some testing myself, since I just found a very cheap source for henna that I could use for this. I am very interested to hear what you guys can find out.

/ CMG

[Tisiloves]

I'm defrosting the second half of a henna batch, whilst not the best control, I'll get back to you witth the results re:stainage (sorry, it's already started dye release)