Tuesday, January 1, 2013

Water Kefir Soda - How Cool is that?!

A selection of sodas in second ferment
After a few days of playing with converting dairy kefir grains, designed to feed on milk and create a high probiotic beverage, kefir, into something that would feed on sugar, I decided to get the real thing: water kefir grains. Sadly, my converted dairy kefir grains did die, and I knew there was a high chance of that happening. On the flip side, the water kefir grains are another side of fascinating.

Water Kefir Grains are yet another symbiotic community of bacteria and yeast (SCOBY) that ferment cane (or palm) sugar. They are a complex, not completely understood, SCOBY that appear to be translucent plastic shipping filler, or something like that. Their origins aren't as clear as that of dairy kefir, which are indisputably from the Caucus mountains. It does seem that they originated in Mexico, but have traveled the world afar, and that they are different from a similar looking and acting SCOBY called ginger beer plant.

More importantly, they are awesome to experiment with. You use the water kefir grains to create mildly fizzy, highly nutritious,  beverages through a one or two stage fermenting process. They are one type of natural soda, or sweet fizzy beverage. And the options are absolutely endless for flavoring. If you follow some basic guidelines, they will grow rapidly... so rapidly that you'll be storing them long term within a week or two.

As with dairy kefir, I am not an expert, but i've been reading a ton. Here's the single best site I've found on the Internet in terms of information and presentation: Yemoos Water Kefir Site

Yemoos has an outstanding FAQ on the left navigation bar, and they also have a photo-full how to on their website. So, I'll just talk here about our experiences and lessons learnt. I have continued to add the details of our experiments to a Google doc, including the ingredients we used, the fermentation time, and the outcome. You can find that here.

Water kefir grains

The Basics
There are a few ways to make natural soda from water kefir grains. We are using the two-step process.
  • First, you ferment your grains in sugar water with some dried fruit. If your water is not hard and full of minerals, you also want to add some other growth supporting ingredients, like a slice of lemon and baking soda.  You can also add ginger here. The key here is to ensure that you have no chlorine in your water. If you have city water, you must let the chlorine evaporate, and you should add the other ingredients. This is about 6 cup H2O, 1/2 cup sugar, 1/2-1 cup grains, 1 tsp. molasses, 1 slice lemon, 1/8 tsp. baking soda. All put into a jar, sealed or not.
  • Second, we strain the grains after 48 hours and start them in sugar water. They will have grown. Even in our cold house (62-68degF), we are seeing growth of nearly 100% every 48hours. 
  • Then, take the water kefir that you have created in the first step into your soda by mixing it with some new sugar source, or leaving it as it is, bottling it, and letting it sit out and ferment another 24-48 hours.  Then refrigerate. In this second step all of your creativity comes in. You can mix 25-50% fruit juice into the kefir, add other fruits, add spices or herbs, extracts...  
A word of caution: In the second ferment, you have a high risk of over-carbonation and  your container exploding if you aren't careful. The kefir is full of yeasts that feed on the new sugar you've added, creating CO2 and alcohol. Bottling that to get the fizz of soda also pressurized the bottle. If you let it sit out too long, it will eventually explode. Figuring out how long is long enough is part of the experiment, it will depend on your kefir, how much new sugar you've added, the container, the temperature of the room, and probably other things. Experiment by using 24 hours as a baseline.

Our experiments

We've only had our water kefir a few weeks -- and we have plenty to share, so if you want to try some out, just let me know! I have been measuring the growth of the grains. It varies, but we've easily seen it double in 48 hours. We are now preparing to start saving some off, both by drying them and sugar packing them into the freezer.

First Ferments. In our first ferments, we aren't veering too far from the basic recipe, since the SCOBY needs to be kept alive. We have tried various cane sugars: white, brown, turbinado, sucanat. We have added and not added molasses. For the dried fruit in the first ferment, we've added figs, raisins, cranberries, apricots, prunes.  We have done a batch with about 0.5oz of ginger -- wow, that was gingery!

Ingredients... The ingredients molasses, egg shell, baking soda, and lemon are all used to support the growth of the kefir and increase mineral content. We have done batches with and without all of them. We haven't used lemon slices yet, as we don't have fresh lemons about, and instead used a bit of lemon juice. Some websites swear you must use some molasses or unrefined sugar, others say that in the winter, the grains do better with fully refined sugar. Mix it up.

Besides playing with the dried fruit, the traditional ingredients, and the addition of something like ginger, don't mess too much with the first ferment -- well, don't use your only grains to do that. Experiment in the first ferment with extra grains, which are easy to come by with water kefir!  

Growth and progress... The first ferments definitely seem to vary in how quickly they ferment and how much they grow, but I can't say exactly why. We have had one mix seem to get "stuck" and after 48 hours it was still somewhat sweet. With this batch, I through the water away, washed the grains and started again. The grains perked right back up. I had used cranberries - and only cranberries - in that mix. Cranberries usually have some oil on them, so it could have been that, and it could also have been that I used only one dried fruit. Not sure.

In our first ferment we are using 1 cup of grains and, for the most part,  the grains are doubling in quantity every 48 hours. We are putting the extra grains in a sugar solution in the fridge, putting them in compost, drying, freezing, or sharing them.

Temperature and time lessons.... Our house around this time of the year runs from 62 deg F to 68 deg F, with the kitchen reaching 70 deg F during a lot of cooking.  The best way to check your first ferment progress is to watch for bubbles and taste it. You can remove the grains when the taste suits you. Just remember that if you let it ferment too long, you could allow vinegar to move in. Too little and it will be sweet and not too carbonated. As long as you "burp" the first ferment occasionally, you won't have problems with carbon dioxide build up and explosions.

What else? For our first ferment, we are using 2 qt Le Parfait flip top glass jars, the old fashioned canning jars. We bought 3 jars on Ebay from Overstock.com for a very reasonable price and free shipping. The 2 qt is the best size, I think. It makes 3-4 bottles of soda every few days and you don't have to adjust the recipe for the kefir.

Flavourings in the Second Ferment. We are transferring the water kefir from the first ferment into standard flip top beer bottles and adding our flavorings. For each batch of water kefir we make, we get 3-4 bottles of natural soda, depending on what flavorings we choose. We are generally allowing the second ferment 24 hours, but we have tried a range of 20-36 hours. All of these choices effect the taste and texture of your final soda.

In the second ferment, we have combined a number of juices with the kefir, as well as jam and different kinds of sugars. We have done:
  • apple, pomegranate, orange and cherry juice mixes from 25-50% of the solution. We have pineapple, grape, and a few others in waiting. 
  • black raspberry and peach jam at 2Tbsp per 16oz kefir (in Grolsch 16.9oz bottles)
  • vanilla extract
  • Lemon juice (2Tbsp) with 1tsp - 1 Tbsp of sugar (we preferred 1tsp),
  • other sugars: honey and maple at 2Tbsp per 16oz kefir
  • cinnamon stick and cloves
  • fresh ginger
You can also add fresh or frozen fruit, but you also have to get it back out of your bottle. :) Puree works pretty well.

How much sweetener?  How much juice or sweetener to add, combined with how long you ferment, will greatly effect your final drink. I like my drink not very sweet and having a lot of champagne like bubbles. For that, I've found a ratio of 4:1 kefir to juice to work well, with 24 hours of fermentation before refrigeration. If I'm adding sweeteners like sugar, honey, and maple, we first tried 2Tbsp per bottle, but that is too sweet and not bubbly enough for my taste -- instead about 1 tsp seems to do the trick. We've also fermented just the kefir alone. Leaving this closer to 36 hours gives a bubbly, somewhat sour beverage.

We have a running spreadsheet on Google docs that you can review, which lists all of the combinations we've made and what we thought of them. It is found here:

Water Kefir Experiments

Carbonation. I've done a lot of reading on carbonation, looking for the one true easy answer. It's not there. The process seems to have too many variables. It seems safe to do the second ferment in an air tight container for 24 hours. We've done 29 hours with a 50/50 juice solution, and this caused quite the "head" on the soda. I would recommend opening jars facing outward, and even outside, until you know how they'll react.
  • 20 hours in our cooler house, even with 50% juice, wasn't quite fizzy enough. The fizz is small concentrated bubbles like champagne, not big bubbles like common soda. 
  • 29 hours with 50% pomegranate juice in a soda bottle filled probably too full (leaving about 2" headspace) had a ton of carbonation and it didn't die over 24 hours after opening. 
  • We started by filling the jars up past the narrowing of the neck of our Grolsch-style bottles and, mixed with juice, had lots of fizz. We backed down to the base of the neck, and at 24 hours, the fizz is quite mild. I think you have to play with how full they are and how long to leave them, as well as, of course, how much sugar you feed them. 
  • All the mixes that we did with just kefir and sugar/spice, no juice, had only mild effervescence.
I feel like we haven't got this down well enough, so we'll keep playing with the main variables.

Containers. For our first ferment, we are using Le Parfait flip top jars, 2 Litres in size. You can use any 1-2 qt. jar.  Whether you seal it or not, or burp it, during the first ferment will change things slightly, but I don't think significantly. For our second ferment, we are using Grolsch-style flip top bottles for our soda that we purchased at Maryland Homebrew in Columbia, MD. They are about $33 for 12 bottles. We also tried second ferments in plastic bottles. Milk comes in type 2 plastic, and it is safer than soda/juice bottles that are type 1. The plastic bottles will push out so you can feel the carbonation. having said that, so far, we haven't been impressed with the fizz of those made in plastic.  We tried the second ferment in mason jars, again with mixed success. We had fizz, but not the full fizz we got from the flip top bottles.

Wednesday, December 12, 2012

Non-Dairy Kefir Experiments, Part 1 of N

This is dairy kefir grains with apricots

So, back in June, I visited a raw dairy farm in Pennsylvania and picked up some dairy kefir grains. I wrote about kefir back then as experiments into a super food. Since then we grew and doubled are number of kefir grains, split them and gave half to a friend.

Dairy kefir, though, takes regular care and feeding to maintain, and you are constantly producing more kefir. Since we also make our own yogurt, I found myself just keeping the kefir alive by replacing it's milk once a week, rather than drinking most of the kefir product.  The plan was to dry the kefir grains, and they can be stored dry for up to a few years.

But, then I decided to investigate whether we could use our dairy kefir grains to ferment other things. I'd heard that you could ferment coconut water, for example, and make a non-dairy kefir. Could I use the grains I have to do that?

The answer is: kinda. You can usually convert the dairy grains to instead take their food from another source of carbohydrates, but there is a high chance they'll die off and they will inevitably stop growing in other mediums. It's recommended, then, that you only use spare grains for this kind of experimentation.

Once you convert your grains to feed off of sugar, though, you can then make kefir soda pop - a fizzy, fruit-drink high in probiotics.  Many people reported success of keeping their converted grains producing soda for over a year, though they had no growth in grains.

Non-dairy kefir is generally called water kefir, and it is normally produced by an altogether different symbiotic community of bacteria and yeast (SCOBY) than the dairy kefir SCOBY that originates in the Caucus mountains. As best as I can tell, there are at least two distinct SCOBYs that produce water kefir, called by different names, but most commonly sweet water kefir (SKG) and ginger beer plant. The SKG are also called Tomi grains and seem to originate in Mexico.

To grow a SCOBY with a sugar-water solution, you need to use a real water kefir SCOBY. I have ordered some of that, so we can see what it is like.. but in the meantime, I went about and converted some dairy grains.

I won't try to pass on the science, as I don't fully understand it and it's documented on the internet. This site is the most authoritative, but also overwhelming, site on kefir on the Internet, by all accounts: Dom's Kefir Website. Another website that has a very detailed FAQ and seems more accessible is Yemoos Nourishing Cultures.  Searches on "water kefir", "converting dairy kefir to water kefir", "kefir soda pop", etc. will all yield lots of results.

 Instead, here's the nutshell of what I've learnt, specifically about creating water kefir from dairy grains.

  • It generally takes several days to convert the grains to eat non-dairy sugars, many sites citing up to 5 days. Mine started fermenting in about 48 hours. 
  • Once converted, it is difficult to convert them back to dairy products. They may die off, and they most certainly won't continue to grow. 
  • The base solution for water kefir contains: non-chlorinated water (spring or hard well water is recommended), some dry fruit, some sugar (about 10-15% solution). Some recommend adding egg shells, baking soda, and if using refined sugar, a bit of molasses. 
  • You need to use the most pure water you can, spring or well water. If you only have city water, you can let the chlorine evaporate by setting the water out overnight. At a minimum, you need to get rid of the cholorine or it will kill off your SCOBY.  Since we aren't on city water, we haven't researched this fully. And hard water is recommended, which is why they add egg shells to the mix. 
  • Varying the types of fruits and sugar you use will vary the taste of your water kefir. 
  • After it has fermented, you strain out the grains and other ingredients and restart the grains in new sugar water. Put the water kefir in the fridge, or... 
  • many people then take the fermented base and add in in a 50/50 solution with some sort of fruit juice for a second ferment. The second fermentation will feed the bacteria and yeast that are in the water kefir solution with a whole new set of sugars. This is generally what is called soda pop kefir.
  • Some people just use one fermentation and start their based with fruit juice, however, this can discolour the grains. SKG also doesn't seem to like to feed on fruit juice, and so the single fermentation is usually done only when using converted grains. 
  • You can feed your converted grains any kind of carbohydrates - various dried fruits, different sugars, to include honey, coconut water, and others. You can't use Stevia, as it doesn't have carbohydrates to feed on.  Most sites recommend unprocessed sugars like Turbinado, Rapadura, etc. 
  • Converted grains produce a slightly more alcoholic drink than water kefir from SKG. Sites seem to provide numbers of 1-2% for converted grains and 0.5-1% for SKG. However, the alcohol content is highly dependent on the type of sugars and the length of fermentation. 
  • You can ferment water kefir either air tight, loosely covered, or opened, and this also effects the end product. 
  • Once the solution is put in the fridge, the fermentation slows way down and you can control the level of fizz that way. The Art of Fermentation recommends using some solution in type 2 (so it doesn't leach chemicals) old soda bottles so that you can feel the level of fermentation with your hands. Everything else says don't fill about the 3/4 mark in the tight jar, but I think this also assumes that you still monitor things and put in the fridge at exactly the right moment. 
  • As far as timing goes, both for taste and for CO2 issues, they say to ferment the grains for 24-28 hours, then do the second ferment at room temperature for 12-48 hours. After this time, you need to put them in the fridge because of the CO2 build up. Also, the ambient temperature of the room really matters, so in Summer you need to exercise more caution.  
Comparing the kefir alone fermenting with a mix of juice and kefir

Here's our first experiments:

  • I took our dairy grains and washed them several times. Then added them to water straight from our well, to get the most minerals possible, with sugar-in-the-raw, a little molasses, dried apricots, and an egg shell.  I put this in a mason jar, filling only 3/4 full, and tightly sealed the jar. 
  • It took about 48 hours to get distinct bubbles rising, and after 72 hours we divided the solution. We put some in the fridge. It was only mildly fizzy, but had a wonderful taste. We took some solution and left it to sit by itself, and we created a third solution of 50/50 with apple juice. 
  • The base solution has continued to ferment but slowly. 
  • The 50/50 solution is fermenting rapidly and has a strong show of bubbles after 24 hours. Tasting it after 24 hours, it still has strong apple juice flavour, but it is definitely not as sweet. 
  • We have started a second base solution using sucanat (a dark unprocessed sugar), fig, and cranberries. This solution is really quite dark and when we started fermenting it, it was sickeningly sweet tasting.  It began fermenting gently after about 24 hours. 
  • My biggest concern right now is controlling the CO2. I don't have a strong understanding of that process or controls, and there a good risks associated with explosion of glass and sugar in the kitchen! And if you keep releasing the CO2, as I've done on some of these, then eventually your fermenting dies down and you loses the bubbles. One good, but kind of expensive, option seems to be flip-top soda/beer bottles for the second ferment and storage. Still, there doesn't seem to be really good information about how to calculate the liquid levels to avoid problems, and I now suspect that's because it's pretty complicated. 
  • The consensus I found in the fermentation Real Food world was to fill the jar 3/4 full for the first ferment with the grains, then when you put them in a soda jar, to leave 1" of headspace.  Their consensus seemed to be that less headspace was more dangerous, but I had home brewers tell me otherwise. Another thing they recommended it to put the fermenting bottles in a place that if they do explode, it's contained. :)
  • In my first batches, I kept burping them because I was worried about the CO2. They did have a nice flavour to them, fermented, sweet but not too sweet. But, with all my opening and closing, they definitely went flat. The other thing was that I took one jar that had the mason lid bulging and put it in the fridge, but 12 hours later it was flat. I am assuming that the jar wasn't quite airtight - not sure. 
Our second batch used sucanat - an unprocessed sugar - that left the grains dark brown!
I am tracking our experiments and their outcomes in a dynamic Google doc spreadsheet that can be found here.  This says what sugars, fruits, timing, etc. we used, as well as tasting outcomes.
Our Sugary Kefir Grains (SKG) have just arrived. They were $6.50 on Ebay.  They are totally bizarre looking. nothing like dairy kefir! so, we'll see how that goes....

Thursday, October 11, 2012

When Life Gives you Green Tomatoes....

Ripen them. 

Last year, a friend of mine gave me all her remaining green tomatoes as the warm Summer nights came to a close and the promise of vine-ripened heirloom tomatoes disappeared. Green tomatoes have the tartness of tomatillos, not to mention the colour, so I turned them into a verde sauce. Cutting them into huge chunks and stewing them with onions, garlic, and hot peppers. Then froze it. This makes for a wonderful cheese (or kale/greens) enchiladas verde later in the winter.

But this year, I decided to experiment with ripening. I took each of her tomatoes, wrapped it in newsprint and put them all in a cardboard box. In addition to her array of huge heirlooms, I had many green paste tomatoes of my own from my ever failing veggie garden. Those i just tossed in a brown paper bag and rolled closed. Over the next two weeks, her tomatoes all softened and turned a lovely shade of red. In turn, I tossed them into the freezer just as they were.

turning unwanted unripened fruit into red gold
This past few days, I grabbed all of the tomatoes from the freezer and tossed them into a pot with some oregano and basil from the garden. Let that stew for many hours so it would thicken (to about half of the original water content). Then run the whole thing through the foodmill real quick to weed out the seeds. Tada. Marina sauce that started with her unwanted green tomatoes. That got popped into jars and canned in the pressure canner. Now we have two quarts of sauce for the winter. Alas, only two quarts. It really takes a lot of tomatoes to make tomato sauce. :(

With a bit of sauce left over, I made my first bloody mary. quite excellent.  The tomatoes had gone from tart to purely tomato. Really pretty amazing.

Simply slice the paste tomatoes and add to the rack
With my remaining paste (plum shaped) tomatoes, I sliced them and threw them in the dryer. Six hours later, I have some very potent dried tomatoes.

several hours later... "sundried" tomatoes.
So, don't toss your green tomatoes or let them rot on the vine. You can just toss them in the freezer (green or ripened) and sort it out later.

Now as we move out of the easy gardening season, I am once again looking forward to the winter CSA with Everblossom Farms in Pa.

Wednesday, August 1, 2012

Cautious Optimism in the Garden

The acorn squash starts white (rear)
Last year I told the story of my endless struggle to grow vegetables in the midst of the woods. Others might think the wiser of it, but every year I give it a go. Last Spring, I bought and then shoveled nine yards (=a lot) of compost to create a raised bed which I enclosed in a 6' high, 10'x10' dog kennel to keep out deer. But, the compost was really not composted completely and was horrible. It killed all my plants.

This year, the raised compost bed is better. It hasn't outright killed anything. The tomatoes were quite leggy though and don't have much fruit, and they don't look great. I did get a decent set of beans from it, chard continues to grow in it, and there is a single tiny watermelon in development.

But the exciting news for me is in the newest bed. Having failed with the compost, I hauled the sandbox I'd made for my son when he was a toddler across the property and adjacent to the dog kennel. I filled it with commercial soil, compost, humus. I planted garlic in November and left it over winter. In the Spring, I put in some beans, peas, and various odd seeds.  So, my garlic did great. At least by my standards, and I wrote about that in June.

Now the exciting news is winter squash. Two winter squash plants -- an acorn squash and a buternut squash -- are taking over the property, running 10' each in any direction. I've never had success with any squash before and I've always been told winter squash is the hardest. But, low and behold, I have squash growing ! There are three butternuts on the vines, and acorns continue to pile up.. there must be ten or more of them now. I'd love to get more butternut, but they seem to have done their thing.

Now, we wait. I can't harvest them for another 8 weeks or so. There is soooo much that can go wrong before then. Deer can come through and eat the entire thing overnight -- that has happened to me before. Bugs are another huge challenge, though I didn't see any squash bug eggs on the leaves. And then there is just rot and other enemies of success.

Keep your fingers crossed !
The immature butternut starts out with green and white stripes - this is about 6" long
Here the white has turned yellow over about a week... it should then, I think, go dark green

Tuesday, July 10, 2012

Science Adventures in a Super Food

After 26 hours of fermenting at 78degF - curdy!
Last month I took a trip to a raw dairy farm in Pennsylvania with a few friends and found myself on a whole new adventure. I'm not much of a raw milk advocate, largely because I don't really understand the whys and hows of pasteurization. But more importantly, because I live in Maryland. The sale of raw milk is illegal here. But the opportunity to buy raw milk from a highly reputable farm couldn't be passed up. I'm not quite sure what we expected a raw dairy farm to be like. It was a small store, probably 30'x8' in size, packed with, obviously, raw milk... cow milk, goat milk... butter... and other classically sustainability-oriented products like pastured meat and local honey. Manning the store was a young boy, probably not twelve years of age. We gathered the bounty of illicit goods and filled our cooler full. Raw dairy. Ooh.

Then my friend said, "They sell kefir. I've always wanted to try that. Do you want to share some?" I'd heard of kefir, but really had no knowledge of what it really was. I thought it was Indian yogurt (wrong). What the heck, I thought, after all, I'm living out of the box here! Our hopes were dashed in seconds though, when the boy said they had no kefir available.

"We do have kefir grains, though, and you can make your own", interjected the boy's much older brother who had joined the room. Make it? Yes, he told us, it's sort of like making yogurt or soft cheese. The idea of trying kefir, this unfamiliar super food, was mildly interesting, but the idea of making kefir, now that was down right intriguing! Right down my alley. A nod, a shrug, and a few minutes later we were proud owners of a bottle of kefir grains. Now we just had to figure out what they heck that meant.
This is what the grains look like... kefir in the pot below

We came home with a small milk bottle of milk with some thingies in it and a set of instructions. Pretty straightforward: put thingies (more formally, grains) in crock, cover with milk, let sit 24 hours, strain out thingies. The liquid left is kefir. Best served as a smoothie made with frozen berries.

All well and good, then the instructions continue that the grains will grow over time. The grains need to be fed, essentially, and can be slowed down in the fridge, but they can be completely dried out and stored at room temperature for years.

So, what in the world were these grains? Not clear.  I did some research. I found kefir to be totally fascinating. Here's some cool things I learnt in the last few weeks:
  • it is really funky stuff.. it looks weird... it acts weird.. tastes a bit weird.. and is very cool... and, apparently, is a super food. 
  • kefir grains have nothing to do with plant material. The grains are globules of bacteria. Healthy bacteria that has powerful properties (probiotics) to support healthy digestive systems. 
  • These grains look like jelly globs. The globs range from pea size to walnut size. We're measuring their growth for a science project. 
  • kefir is actually a fermented dairy product with less than 1% alcohol content ....
  • you can use any kind of dairy, and now that we quickly ran out of our raw whole cows milk, we're trying pastured pasteurized whole milk from South Mountain Creamery...
  • kefir tastes like a very yeasty plain yogurt, but it's more unattractive to look at...it is definitely a liquid, with curded flakes that separate out... and I should say, our kefir because... 
  • kefir originates from the Caucuses and is passed along through the growth of grains...
  • attempts to reproduce kefir in a lab setting have failed, and it is unclear exactly what all the bacteria in the grains are.... 
  • as I understand it, the grains will also change based on the bacteria in the environment they are in, so, it seems, your kefir is somehow uniquely your own... 
  • kefir made commercially is not really kefir, but a dairy product made with major bacteria strains from kefir grains... 
  • same is true of things called kefir culture... they are a few of the extracted bacteria and can't be used to grow kefir grains over time...
  • when your kefir grows enough, you can split it and share it, but you have to keep feeding it by replacing the milk it sits in weekly... like sourdough... 
  • it takes a little bit of work, a few minutes a week, and some forethought, but is pretty easy to manage...
  • when you puree kefir with frozen blueberries and sugar it tastes just like a yogurt smoothie. 

There was a great video on fermented food by Sandor Katz, author of The Art of Fermentation,... there is a section on kefir, but the whole thing is fascinating.


My son also found interesting YouTube videos on making kefir with coconut water, instead of dairy... to make fermented beverages.. called water kefir....