Posts Tagged ‘Noma Guide to Fermentation’

Fermentation V: Water Kefir

I am experimenting  with kombucha and its culinary uses, but for daily drinking I prefer water kefir. It’s a fermented drink with a mildly yeasty tangy flavor and none of the vinegary overtones of kombucha. It can be flavored in a lot of ways, and it’s quick and fun to make.

It’s produced by a SCOBY, a symbiotic colony of bacteria and yeast, but rather than form a solid mat the kefir SCOBY forms rounded globules called “grains.” I had trouble getting started because I kept buying dehydrated grains that never came to life. Finally I bought fresh grains from Florida Sun Kefir and they got off to a flying start. The substrate is water with 1/4 cup of sugar per quart of water dissolved in it. I use a mixture of white and coconut sugar, and brew about two quarts at a time. Pour the water mixture over the grains, screw the lid on loosely or cover with a dish towel tied on tightly, and let it sit at room temperature for 36-48 hours. The grains are in motion during fermentation, rising through the fluid, discharging their cargo of carbon dioxide into the air, and sinking slowly back to the bottom of the jar. They will slow down as the sugar is exhausted. I tell when it’s ready by tasting. When the sugar is fermented totally and none is detectable to taste, it’s done.  I pour off most of the fluid in the jar through a mesh strainer and refrigerate until I want to drink it. If you want yours a bit sweet, stop sooner, but I prefer to sweeten artificially before drinking. Leave the grains in enough finished kefir to cover them, add more sugar water, and the grains are off and running again.  I then add flavoring and some artificial sweetener, carbonate in my nifty Drinkmate, and enjoy. My favorite flavorings are vanilla or a little good root beer extract or a bit of grated ginger juice. There are all sorts of possibilities including adding fruit juice.`

I find the Drinkmate to be the easiest and most exact method of carbonation. I have found the “natural” method to produce erratic and undependable results, but if you want to try it, try out these directions: http://www.resetyourweightbasics.com/healthy-kefir-soda/.

I can’t explain this, but water kefir really does seem to decrease appetite. I don’t vouch for this effect because I do not find any scientific literature on it except the one animal-model reference below,  but try it for yourself and see what you think.

Your grains will multiply steadily and always need food. If you want to store them for awhile, put the jar in the refrigerator immediately after adding fresh sugar water and they will keep about two weeks. For longer storage, drain them every two weeks and add fresh sugar water. You’ll soon have plenty of grains to give to friends.  Internet sources tell you to add dried fruit and eggshells for minerals, but I have never done that and my grains multiply  just fine. It might be that the coconut sugar I use provides the grains with any minerals that they need. My grains are tan rather than white after several generations in coconut sugar.

In the picture below, what looks like a film on the surface is actually a haze of tiny bubbles of carbon dioxide bursting.

One caveat: I can’t find reliable data on this but judging from its effect on me I think that my homebrew kefir has substantially more alcohol that most SCOBY-brewed products, maybe as much as 2-3%. This might not sound like much, but you don’t want to work or drive on the amount of alcohol in a standard 12oz glass. I keep this for evening enjoyment. But I may be incorrect about this,or brewing conditions may affect the ethanol content. Here’s a marvelously nerdy article analyzing the components of water kefir: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3993195/pdf/zam2564.pdf

I can’t stop talking about the marvelous Noma Guide to Fermentation. It doesn’t address water kefir specifically, but I’m curious about the possibilities of cooked-down kefir essence used in the way that the Noma people use kombucha essence. It might also be possible to grow out water kefir grains in other fluids such as juices. After making a few batches of standard water kefir, you will have plenty of grains with which to experiment.

Many internet sources that discuss water kefir give references for its health benefits. However, I spent a cold gray afternoon indoors looking up those references and found that, as I had suspected, nearly all of them actually refer to milk kefir. I don’t find a lot of data on whether water kefir contains the same microorganisms as the milk product, and certainly its nutrient content is different. Here are a few references on water kefir specifically.

Inhibition of metastasis of breast cancer cells in vitro and in vivo in a mouse model:

https://www.ncbi.nlm.nih.gov/pubmed/27230756

Isolation of a novel bifidabacterium strain with probiotic potential from water kefir:

https://www.ncbi.nlm.nih.gov/pubmed/26739269

Analysis of organisms from water kefir, showing that its biotic complexity is higher than previously realized: https://www.ncbi.nlm.nih.gov/pubmed/23289707

Evaluation of Lactobacilli strains found in water kefir for probiotic potential:
https://www.ncbi.nlm.nih.gov/pubmed/30319846

Anti-obesity effects in an animal model of water-soluble polysaccharides found in the matrix of kefir grains:

https://www.ncbi.nlm.nih.gov/pubmed/29084388

This last one is particularly interesting because the mice given kefir matrix exopolysaccharides showed anti-obesity effects on an excessive diet and also showed higher levels of Akkermansia bacteria in their feces. Other data (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3670398/ ) indicates that the presence of Akkermansia species in both rats and humans inversely correlates with obesity, probably via interactions with the gut epithelium. Please don’t try to make too much of this: the science of the biome is in its infancy and we know very little about how to impact it for specific effects. So I can only say that water kefir won’t hurt you and may have some beneficial effect.

 

 

Fermentation II: Black Garlic and other goodies

 

 

Yesterday’s post was about a truly remarkable cookbook, The Noma Guide to Fermentation. Today I’ll talk about a kind of high-temperature enzymatic reaction, the making of black garlic and other blackened goodies. Properly speaking this is a Maillard reaction and not a fermentation, but let’s not quibble when the result is so delicious.

These products need to be made at a temperature of 140-150 degrees. This is hard to achieve without a specially built chamber, although I notice with interest that a household appliance built especially to make black garlic is available on Amazon. A rice cooker on “keep warm” is suggested, but mine turns off automatically. I am trying my large crockpot on the ‘keep warm” setting and the lid cracked to keep the temperature lower. But the process takes weeks, so I also bought some finished black garlic ready to use. If you go in for this cheat, you have the option to get the Asian kind that is one single huge clove of garlic about an inch across as shown above, but if you buy from Black Garlic North America you can buy it peeled fairly economically or (my choice) you can buy 1.5 pounds unpeeled and have the skins available to put in simmering chicken stock, giving it wonderful depth.  It is also sold in tiny little packets in many grocery stores, but I do not recommend that form. It is often dried out and unpleasant by the time you get it when it should be moist, chewy, and have the complexity of good balsamic vinegar with a different flavor.

As for using it, one of my favorite simple uses is to pound two huge single cloves or 5 to 6 regular cloves of black garlic to a smooth paste in a mortar and pestle with a little salt, then pound in 2 tablespoons of cold butter and a teaspoon of very good balsamic vinegar (nothing from the grocery store.) Pound until you have a smooth mousse-like paste, then use it to top steaks, spread it on bread, or toss with a little pasta. To make the heavenly sauce above is only slightly more complex. Make the black garlic butter paste as described. After pan-grilling a nice bit of steak, while the steak is resting deglaze the pan with water or red wine, boil down the fluid hard, add a cube of beef glacé from the freezer, and when the glacé is melted, add the black garlic paste and stir in thoroughly. Add a little water to thin the sauce to desired consistency, taste for salt, slice the steak, and pour the sauce over the slices.  This amount of black garlic paste makes enough for two people.   The recipe is very adaptable and doubles easily.  It’s rich and meaty, full of umami, and enhances everything it touches.  Tart it up with some extra butter if you want it even richer.  It also does wonderful things for ordinary supermarket cremini  mushrooms, and even better things for more flavorful mushrooms like shitakes.  Needless to say, make beef glacé if you don’t have it, and don’t even think about using a boullion cube. Or pound out the garlic cloves without adding the other ingredients and put them in vinaigrette.

Above, several regular-sized  cloves of black garlic were pounded and roughly mixed into half a cup of red wine vinaigrette and spooned over cold sliced steak, sliced avocado, and salad.  This might sound like too much but the flavor of black garlic is mellow and surprisingly low-key and you need a lot when it’s the main flavoring.

I was rather startled to find that all kinds of miraculous health benefits are attributed to black garlic, to the extent that it is sold in capsules for people who want to take it more conveniently. That anything as meaty and delicious as black garlic should be ground up and put in capsules is weird to me, sort of like taking steak in capsules, but suit yourself.

Incidentally if you grow a lot of garlic and have trouble storing it through the winter, it might be worth rigging up a chamber so that you can make black garlic in quantity. I would imagine that it could be sold quite profitably at farmers markets, since I almost never see it in those venues. However, I am nowhere near handy enough to tell you how to make a 140 degree chamber without burning down your house. Know your limitations.

‘The ”other goodies” refers  to the fact that the same process can be used to blacken some other foods, with varying results. Please use the Noma people as your guide if you want to try this, since I am experimenting with it but my products are not ready yet. Their descriptions of apples blackened in the fermentation chamber, then dehydrated until chewy, then coated in very dark chocolate, sound luscious. I am blackening some quinces, and I’ll report back if the result is worthwhile.