How can I maximize ginger extraction?

To increase flavor extraction (and this applies to ALL flavors, not just ginger):

• Simmer for a prolonged period (more time to extract flavor).
• Puree or finely mince the ginger, then strain it out with a fine chinois or cheesecloth. Smaller pieces allow water to more easily penetrate, and allows flavor compounds to be extracted more quickly
• Stir frequently; this greatly reduces the time you need to cook the ginger, by ensuring flavor compounds reach an equilibrium throughout the mixture, rather than being concentrated at the surface of the ginger pieces.
• Cook the same ginger multiple times with fresh water each time. This will extract more flavor than doing one batch cooked 3x as long, and also more than cooking the same ginger with 3x as much water. Each batch will be less flavorful, of course, but after 3-5 batches, you should have most of the flavor out.
• Reduce the ginger water after extraction to concentrate the flavor. This will be especially helpful when combined with multiple batches.
• Add alcohol to the water, as many flavor compounds are oils, and thus more soluble in alcohol than water. This is excellent to combine with reduction, as the alcohol is easily evaporated.

All of these approaches are based both practice and the chemistry behind extractions, which is what you are doing here.

Do you want the flavor of raw ginger, or cooked ginger flavor? Ginger contains several not very water soluble flavors, some of which are converted by cooking into different not very water soluble flavors.

To maximize flavor, you want the ginger mashed as finely as you can make it. That increases the surface to volume ratio of the stuff which in turn maximizes extraction.

Whether you cook or not, consider adding some alcohol, vodka should work, say 20-50% by volume to the mash, or the mash after it is cooked and cooled, and letting things steep overnight. The alcohol should increase the efficiency of extraction of the not very water soluble flavor oils. Filter afterwards of course, a coffee filter and a collander will work for that if you're not in a hurry, perhaps with a cheese cloth step to catch most of the bigger chunks.

I think that trying some room-temp preparation and cold extraction techniques to preserve and incorporate the tasty volatile compounds/organic acids/etc into a suspension/emulsion concentrate will serve you well.

This is done by harnessing the power of the "salting-out" effect to help create a more potent water-loving-compound-extraction, followed by a more lipophilic treatment to round up the rest of the flavor compounds, finished with a stabilizer/emulsifier for shelf life and rancidity control.

I am suggesting a suspension/emulsion because, only some of the ginger's flavor compounds are water-loving and we want to be able to spread them all out fairly evenly in the end product. You will either wind up with something like a salad dressing emulsion that separates, but will reincorporate if shaken, or a thick gel suspension for dilution. To design this emulsion, let's take a different approach to some of the steps that BobMcGee outlined.

Here's what I was thinking:

First, freeze your ginger. Once the root is frozen, peel it(yes, a regular vegetable peeler works, BE CAREFUL THOUGH!), and then grate using a fine microplane grater. You will end up with a pulpy-ginger-mash with very few long ginger "hairs".

Freezing the ginger helps disrupt the cell walls of the rhizome(water in the cells expanding upon freezing), and will slow down native enzymes inside the ginger. Also, grating frozen ginger(for me) seems to go faster than grating raw ones, and there are fewer of the hairs to deal with when you're finished grating. This helps me get the very smallest ginger pieces possible, since I don't have a vitamix. :-(

Combine lengthening extraction time with reducing ginger water by allowing excess water to evaporate in the fridge or on your kitchen counter-top rather than heating. Some of the flavor molecules in ginger will change when exposed to temperatures greater than 50F, thus changing the flavor. Not that warmed ginger isn't also good, but not heating the solution leaves flavor options for you to explore later, rather than being stuck with only cooked ginger flavor. You are realistically going to need to do at least one water extraction and one oil/alcohol/fat extraction to get the majority of the ginger flavors. Increasing the holding time for both extractions is key, so be lazy...let them sit at least overnight. Below is a process I use.

Two-phase extraction example:

1. Water extraction

20g of frozen ginger, peeled then grated into a pulpy-mash

100mL water

2g CaCl dissolved in water

These are combined in a glass jar with a cheesecloth top that is placed in the refrigerator(at least overnight).

(You can either use invertase to cleave the sucrose in the ginger into glucose and fructose thereby utilizing the salting-out effect, or use calcium chloride to help drive the volatile compounds out into the aqueous phase. If you use invertase, allow the water and ginger solution to sit on the counter, not in the fridge)

When you're ready for the oil extraction, filter and reserve the aqueous ginger solution in a separate container, you will need it later.

1. Alcohol/Oil Extraction

Ginger-mass leftover from the previous step

100mL 40 proof alcohol (you could use a higher proof, but I use the lower proof because there is a little water left in the ginger mass from the previous step) Personal preference is to use mescal(mezcal?) or a bit of nice brandy/congac.

The alcohol and ginger slurry I allow to sit in the fridge covered with cheesecloth for a while...at least overnight. I tend to forget about this for a week and then find it again when I'm rearranging the fridge. The longer I let the alcohol and water evaporate, the more fiery it becomes.

I blend the two constituents with an immersion blender, cover with cheesecloth and then let the solution sit overnight in the fridge. I have in the past used a neutral oil(canola & grapeseed), but I needed to let it sit in the fridge for more than a week to get more flavor out of the root.

Here's where the concentrate/emulsion making occurs:

I use xanthan gum and lecithin to get the right concentrate consistency, and to slow release of the volatile compounds. I also like xanthan because it is a thermoreversible gel if memory serves right. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3866759/ http://pubs.acs.org/doi/abs/10.1021/jf048111v http://www.sciencedirect.com/science/article/pii/S0308814607009624

Add some xanthan gum to aqueous solution(in these proportions I used 2.3g) This will help prevent the loss of the volatile compounds to the air as it is stored. The result is a bubbly light-yellow goo. Slowly incorporate the oil/alcohol solution with 1/4 tsp of lecithin(again, I use the immersion blender to do this) then finish with salt (punches up the flavor). To control rancidity I would either add alpha-tocopherol(vitamin E) or turmeric to take care of free radicals that may occur during longer-term storage.

All said and done, this is a slower process because it requires evaporation at cold temperatures. This method does however allow you to make a "concentrate" or extraction without adding sugar, or using heat...if that matters. I do it this way because it allows me to be lazy,(I leave this in the fridge covered with cheesecloth for more than a week getting rid of the water sometimes.) and it means I don't have to worry about cleaning up melted sugar from a saucepan later!

What about juicing the ginger? That method is also espoused, e.g., for making ginger beer. I've done it before and it works quite well. You could also try infusing the ginger in the spirit by letting chunks of ginger soak inside the bottle for a week or two. Finally, if your budget is limitless, you could also try using a rotary evaporator to make a ginger extract.

Edit: If you don't have a lever juicer (like the one shown in the first link), another method that I've used before is to grate the ginger into a cheesecloth (or even a paper kitchen towel will work) and squeeze; you'll get about a teaspoon of juice per inch of ginger root. I often use that to add ginger flavor to dashi stock, which works quite well.

Slice ginger thinly Soak overnight at room temp by just covering it with grain alcohol:water (1:1) or vodka/water 1:1 Drain and use the liquid

How about trying a pressure cooker. I've tried it once and the flavor was great but I also added sugar and was too sweet. So next time, which is today, I'm going to with-hold the sugar and sweeten it later. I'm using 2 cups of minced ginger to eight cups of water. I can always reduce the mix later if need be, but I doubt I will have to. I'm also adding the zest of to lemons. JB

Cut up ginger into thin slices and steam for 30 mins. Then air dry the ginger. This process concentrates the ginger and also slightly changes the ginger to a different form which will warm the body more than simple fresh ginger extract.

To use, put some of the dry ginger in water and boil them together ( do not put the ginger into boiling water ) Boil for about 5 mins.

There are lots of good ideas about extraction here. Generally, in processing terms, there is always a compromise between how watery your extract is and how depleted the pulp is. There is a further question which can be important: a more completely extraction may not be the most desirable, brewing coffee and tea has this problem. The "optimal" for the compromise is always a multi-step process, use small amounts of solvent (water, alcohol, etc) in each step, mix well, then squeeze as much liquid out of the pulp as possible, repeat. Better still, you want to mimic counter-current cascading extraction, start with fresh ginger and a previous extract rather than pure solvent water/alcohol. Then use water thereafter.

One method I am surprised that has not been mentioned is "cavitation", putting the ginger mash and water/alcohol into a soda siphon, pressure it up with a couple of gas (nitrous oxide or carbon dioxide) canisters, shake it violently every so often and keep it cold, and after an hour or so, release the gas by pressing the siphon trigger (careful that it may spit foam). Those who swear by this method argue that you get good extraction without much waiting or effort. I have not been able to confirm its efficacy versus other methods and remain somewhat doubtful. It would be interesting to do some measurements with an HPLC to show how advantageous this really is.

Cheap concentration trick:

There is a slow trick you can use to concentrate your extract (before you put any sugar into it) - cheap freeze drying. Put your final extract into an ice tray, leave in in the freezer for a few weeks and watch the cubes shrink. Water sublimates from the cubes over time leaving behind the same amount of extract in less water. Once it has shrunk (you have to decide how far is enough), thaw the cubes and sweeten with sugar.

I'm doing ginger extraction experiment right now with soxhlet apparatus,I'm using 50% ethanol as a solvent. I hope I will get a best result with this concentration.

Here's what I did:

I used the juicer first, and filled an ice-cube tray so I can use one cube (small) per tea.

I collected the rest of the fibre/pulp left in the juicer parts together in a jar and poured hot water in it - twice.

I never got so much concentrated ginger from that root! It was a big root, which would have provided me about 16 cups of ginger tea. I made 21 ice cube shots and 1 litre of concentrated ginger tea (enough for at least another 8 strong cups)!