Water Curing Explained
The following is an extract from the now defunct Overgrow site. I made a few edits and added in the images. While, I myself have never cured using this technique, I have smoked water cured weed at a few occasions and I really liked it, the taste is so clean and smooth.
Introduction - What is the water cure?
The water cure has only recently come to light as a widely accepted form of curing . Water curing uses osmosis to flush out the chemicals, chlorophyl, pesticides, pests, and anything else you would rather not be smoking. The water cure is also very fast (about 7 days) with optimal quality (as compared to 30 days air curing), and as well does not stink like an air cure does. Water-cured buds are also more potent than air-cured (however there is proportional weight loss to potency increase).
THC is not water soluable, and the bud is protected from air/light, enabling potency to be maintained at it's highest levels, while the nasty chemicals are flushed out. Some growers report being able to add nutes all the way up to their harvest date because the water cure takes care of the built up chemicals.
Why would I want to do it?
Because of its speed, stealth and clean taste, water cure is very inviting to most non-commercial growers. The commercial grower might not be attracted to the water cure, as the weight of the bud is diminished.
Water cure can also be attractive to those smoking/cooking with suspect cannabis (schwag), moldy bud, pest infested bud, unflushed bud, etc.
How will my bud taste/smoke/smell/look?
Properly water-cured buds (submerged for 7 days and properly dried) will have a clean, thick taste when smoked, as well as being more potent than air-cured buds. This is one of the major advantages to the water cure; a quick drying process that retains potency and has a clean taste a flavor.
Smoking reports vary, however most people agree that water curing provides a very clean, smooth taste. Those with hashier, sandlewood/piney and harsher strains will find this method enjoyable for the clean, thick flavor without the edge (like a fine whisky).
However, those with frutier tasting strains have mixed results. They report the smoke is almost too smooth - much of the fruity/citrussy flavor removed.
The smell of the bud is greatly diminished, which many believe is one of the positive side-effects of water curing. Some also report a diminished smell in the smoke itself.
Remember, all that bud looked the same when it was harvested, the difference in appearance is due to the different methods of curing
Water-cured buds tend to look more earthy and dark in tone. Some say the bag appeal is decreased, however proper care while water-curing can improve bag appeal.
Water cure vs. air cure - note that while the Chlorophyll (green color) leeched out in the water cure
What do I need for this?
1. A container hold your bud and appropriate water (about 4 times as much water as amount of bud). A cooler with some kind of drainage works great, or for smaller quantites use a mason jar with holes punched in the lid.
2. A dehydrator or low-impact heat device. Dehydrators work great and cost about $40 from walmart. Radiators work well (as long as it isn't too hot), and some report using hair dryers.
3. A cool, dark place to put the water-curing container.
What is the process?
You need at least 7 days to do this, any less than seven can result in undesireable quality. Even 5 days in water is not enough - you need seven!!!
Plop in your freshy cut buds (or schwag, whatever, but fresh buds work best) into enough water to completely submerge the buds. The buds will float to the top for the first few days of this, so you need something to hold them down (a block of wood, a plate, etc). Change the water every day for 7 days, any less than seven could result in undesirable results (trust me). Try not to disturb the buds when changing the water as plant material can break off more easily (read: trichomes). Always keep the lid of the cooler open, do not seal off the container.
The water may take on a yellowish/greenish (even brownish) tint each day, moreso as the bud becomes completely saturated with the water. It will probably also stink. This is good, as it is the nasty chlorophyl and salts exiting your plant.
After 7 days remove the buds from the water. They will be sopping wet, and can be dried relatively quickly. MPD (and many more of us) purchased a food dehydrator from wal-mart for about $40 and consensus tells us this may be the best method for drying. Put the dehydrator on the lowest setting and dry for about 5 hours or so.
Radiators and other low-impact heating devices can also be used. Users have reported hair dryers working with some success, as well as hanging the wet buds on a clothes line with a fan circulating air. The important thing to do is to ensure the buds dry quickly enough to not become moldy, but with as low-impact of a drying environment as possible.
7 DO'S and DON'TS of water curing
1. Do not close the lid on the cooler. As the chlorophyll bleeds off into the water it evaporates - this is good and sealing the cooler just puts the crap back in the water.
2. Keep out of direct sunlight. I just put the cooler in the garage and that's the end of that.
3. Don't stir or agitate. This serves no useful purpose.
4. Don't bother straining the water for trichomes when you change it each day. I've tried it countless times and have yet to get enough trichones to make it worth the effort, though some hairs will break loose.
5. I've water cured as long as 9 days, but there was no real improvement over the 7 day mark - so why bother?
6. Do use a dehydrator. They cost $40 over at Walmart and you set it on the lowest possible setting. Mine takes about 5 hours to dry out a 1/2 pound of sopping wet buds. If you line dry make sure there is a drip tray or tarp for them to drip on.
7. DO NOT water cure seeded buds that were intentionally seeded so you can harvest seeds. Air cure these buds only...
What is the dry-weight ratio comparison with air curing?
Dry weight using air cure usually returns about 25% of the freshly cut bud weight. That means if you had 10 grams of freshly cut plant, you would get about 2.5 grams dry.
Water cure, on the other hand, returns about 15% from wet to dry. In our 10 gram example, that would be about 1.5 grams.
So why is there less weight using water, but more potency?
THC is not water soluable. When the buds are underwater, they are protected from environmental conditions such as humidity, over exposure to air, temperature, and light. This consistent state is something not easily achieved through the traditional air cure, which can be prone to a harsher smoke with decreased potency if everything isn't just so.
Water cure enables the removal of undesireable elements from your bud while retaining potency.
How potency is increased through the water cure
I should explain this so that the conspiracy theory kooks don't land on me like a ton of bricks.
Here's the "magic" behind the increased potency you get by water curing.
For the sake of making it simple, I'll use an example of 100 grams of bud going into the pot.
Now, you had this bud assayed and know that 15% of it is pure THC.
15% of 100 grams is 15 grams. So in our example the 100 grams of fresh bud has 15 grams of THC in it.
You water cure it and dry it. Now you have only 70 grams of bud left. WTF?
But you are deceived because the 15 grams of THC is part of the remaining 70 grams of bud. 15 divided by 70 equals 21.42%.
Sooo....
The mass didn't change, just some of the things that were there - aren't there anymore, so what is left becomes a bigger proportion of the entirety.
You go assay your water cured bud and find out it has 21.42% THC content - a 50% increase in potency.
Not bad, eh?
How osmosis leaches nasties, saves trichs
In air, chlorophyll breaks down at a rate that is only slightly faster than the breakdown rate of the resin - hence the reason the pot is dried for a short time then placed in jars and burped - but always out of direct sunlight because sunlight plus air equals an ideal situation for the THC is to break down and thus a loss of potency may ensue.
In water, the chlorophyll breaks down (out of the plant) while the THC remains suspended in the resin and is relatively unaffected by the surrounding water medium.
More on chrlorophyll removal
Water curing and air curing are doing exactly the same thing except you retain flavour and smell with air drying and with water curing you lose that flavour and smell but you have a smoothe smoke....
The Chloryphyll in the plant leaves through either the water evaporating (air cure) or through osmosis into the water around it...Water curing is obvously more affective at removing chloryphyll because you are adding more water, and the smoke is smoother (chloryphyll is a big factor in bad tasting and bad burning weed)....however smell and taste come from terpenes in the plant that are also water soluble so they are lost in the water curing process....
In air curing the chloryphyll has to leave by the evaporating water in the bud....this is less affective but you keep those smell and taste terpenes.....so why after going through the trouble to preserve and develop them through air curing would you dunk them in water and lose them?
Its either one or the other
What about already dried buds/shwag/moldy buds?
Many have reported success in re-curing nasty buds of one kind or another. Dry schwag that is still in a nugg-ish form can be water-cured, as well as semi-moldy buds (however, no miracles here).