The results from the aforementioned piima cream experiment (wherein I try to culture cream with viili) are in:

On the left is a jar that contained a very high proportion of viili culture to raw cream. This produced a very thin, more kefir-like beverage (in the bowl on the left), quite tart. On the right is a larger jar that contained much more cream in relation to viili culture (I just poured in enough viili to coat the sides before pouring in the cream). This produced a much thicker, very mild-tasting and lovely slightly soured cream (the bowl with the spoon in it) which immediately made me think of ice cream, so we stuck the inner chamber of the ice cream maker in the fridge in preparation. I've never tried piima cream, so I can't judge the results properly, but my guess is that the one on the right is most like piima.

About 48 hours later, the ginger water kefir that I set up on Wednesday was nice and tart (although still thin-tasting, a general complaint I have about water kefir), so I bottled it Friday.

Due to inadequate closure of the little baggies of water kefir grains, some of the grains had gotten loose and were floating among the pieces of grated ginger (a hazard of putting the ginger loose in the sugar-water rather than laboriously juicing it).

Other than that, the process went pretty well, I felt, so I set up another batch, but first I cleaned off those loose grains, then emptied out the bags of grains and cleaned those and separated them out in smaller amounts into more bags because they were looking a little crowded...

Here's a look at all the things I had going in the kitchen Friday (that being the cooler of the two "fermentation stations"):

Now the kefir (back right) is strained and in the fridge, as are the two jars of experimental piima cream (wherein I try to culture cream with viili) in the front.

My recent experiments with water kefir have been mixed.  Of the first two batches, the one with dried apricots did quite well-- a little thin-tasting, but nice and tart and a little carbonated-- while the one with dried cranberries turned muddier and muddier (the rapadura I used lending itself quite nicely to that) with an unpleasant thickness to it, and the grains became quite murky and mushy.  Note to self: no more dried cranberries.  I put those grains in sugar water in the fridge to rest for about 24 hours, and they actually made a very tasty drink out of the sugar water.

In the meantime, I put the other batch of grains into another batch of sugar water with the same apricots.  This batch fermented to tartness very quickly, without much depth of flavor.  Note to self: don't reuse dried fruit.

I read that water kefir grains seem to love ginger best, and we love ginger beer best, so yesterday, I decided to try making ginger water kefir according to Dom's recipe.  We couldn't find fresh young ginger, so I used what we had, but otherwise followed the recipe to a T, even adding the blackstrap molasses despite the fact that I was using rapadura as the sugar (because that line of the instructions got hidden at the top of a following page of my printout).  Baking soda, check.  Eggshell, check.  Spring water, check.  Dried Turkish fig, check.

I mixed it all up, put a lid on it, and came back to stir it after about 24 hours, then stirred it again later this evening and tried some, only to discover that just about all the sweetness was already gone!  Drat.  So... what to do?  I bottled it, in four beer bottles, and I'm keeping an eye on those caps.

I mixed up another batch right away, but first I checked on the grains.  Both batches were looking OK, the mushy ones that had been in with the cranberries a little less so but still not as pristine-looking as the others, so I took them out of the tea bag and rinsed them in a piece of cheesecloth under running filtered water to get rid of some of the mush.  I realize that a lot of that mush may have been new young grains, but they didn't strike me as very healthy new young grains, so down the drain they went with the water.  I was surprised by how nice they turned out after their bath, shave and a haircut.  Almost exactly like the other bag of grains.  So in they went together in the new batch of ginger, which varies from the first in that I left out the molasses and decided to put the grated ginger straight into the liquid rather than bothering with the arduous, dirty-dish-making process of juicing it with sugar.

Last week, I was feeling discouraged by the state of the uneaten viili in its jar in the fridge and decided to try to make cheese out of it.  We've made "farmer's cheese" or cream cheese-- a simple, soft, spreadable cheese-- out of soured and clabbered milk before, and I followed that model.  I poured the viili into a cotton napkin over a jar and let the whey run through, leaving the viscous solids behind.  This took a while, and I transferred it to the fridge after a bit.  Normally, what runs out into the jar is just translucent whey.  In this case, there was quite a bit of more opaque, white viili that ran through, too, and I let it, squeezing the napkin every once in a while to make sure that all that was left behind was what was really solid.  When it was quite dry, I transferred it to a bowl and mixed in salt, pepper and herbes de provence.

I accidentally made it a little too salty, but otherwise, it's quite nice, with a very nice, silky texture and mouthfeel.

Encouraged by that success, and having started a new batch of viili to replace the old (I'd reserved some as a starter), yesterday I went looking for something to make more cheese out of.  I knew I'd be picking up dairy from Pennsylvania today, so I needed to clean out the fridge and make a bit of room anyway, and the last batch of PA milk was too sour to enjoy on its own, so I took that out and let it finish separating on the counter, then did the same thing, letting it drip overnight in the fridge before mixing the solids with the same herb blend this afternoon.  Since I started with more milk than I had viili, there was more whey and more solids.  Believe it or not, I added a little too much salt again, but other than that, it's good again, without quite the same texture but otherwise similar.  It's interesting to me that there isn't more difference, actually.

A friend of mine asked for a transcription of the recipe for Ginger Beer. Rather than just email him, I thought I'd post it here. The canonical recipe here is from Sandor Katz's excellent book, Wild Fermentation (look past the garish cover; good stuff inside).

Ginger Beer canonical recipe

Ingredients

3" fresh ginger root (or more)
2C sugar
2 lemons
water

Process

1. Start the "ginger bug": Add 2 teaspoons grated ginger (skin and all) and 2 teaspoons sugar to 1 cup of water. Stir well and leave in a warm spot, covered with a cheesecloth to allow free circulation of air while keeping flies out. Add this amount of ginger and sugar every day or two and stir, until the bug starts bubbling, in 2 days to about a week.
2. Make the ginger beer any time after the bug becomes active. (If you wait more than a couple of days, keep feeding the bug fresh ginger and sugar every 2 days.) Boil 2 quarts of water. Add about 2" of gingerroot, grated, for a mild ginger flavor (up to 6" for an intense ginger flavor, and 1½ cups sugar. Boil this mixture for about 15 minutes. Cool.
3. Once the ginger-sugar-water mixture has cooled, strain the ginger out and add the juice of the lemons and the strained ginger bug. (If you intend to make this process and ongoing rhythm,  reserve a few tablespoons of the active bug as a starter and replenish it with additional water, grated ginger, and sugar.) Add enough water to make 1 gallon.
4. Bottle in sealable bottles: Recycle plastic soda bottles with screw tops; rubber gasket "bail-top" bottles that Grolsh and some other premium beers use; sealable juice jugs; or capped beer bottles, as described in chapter 11. [Chapter 11 not included here. -- Ed] Leave bottles to ferment in a warm spot for about 2 weeks.
5. Cool before opening. When you open ginger beer, be prepared with a glass, since carbonation can be strong and force liquid rushing out of the bottle.

Matt's Notes

The Bug

Starting the bug can be tricky, and I can't seem to figure out the circumstances which lead to predictable success, or a slow-to-awaken bug. Temperature seems important. Once, I took some of the bottom-of-the-bottle sludge from a good bottle of ginger beer and used it to start a bug. This bug was crazy and was active in merely hours -- more active than any previous bug I had started. The ginger beer from this bug fermented out all of the sugar in about 1-2 days, and it therefore didn't taste very good (and it really exploded when opening, always wasting half of the bottle down the sink.) Still, I think that there is promise in this method.

A healthy bug isn't subtle; you won't have to guess if it's working, since you can hear it fizzing.

[sound clip here, someday]

If you're worried, or wondering, or it looks funky or smells funky, probably best to start-over.

Note: beer-makers know a lot about cultivating yeasts, which is what we're doing here. They say that during brewing, many thousands of generations can go by, leading perhaps to some evolution or mutation in the strand, which may make it unsuitable for another batch. So, they usually don't re-use yeast in a serial fashion, unless they're experimenting. I'd expect that similar principles might apply for ginger beer, though the process is much shorter and the flavors much less dependent on the yeast. It might be worth playing with running a few batches in a row, starting each successive batch from the previous batch's sediment, just to see what happens.

Also, once we started a bug with rapadura sugar (see below) rather than white sugar. This bug got started and got vigorous very quickly. My unsubstantiated theory is that this sugar has more minerals and other nutrients that the bug likes, whereas pure white sugar just has sucrose.

Yeast

The theory is that the yeast comes from the skin of the ginger root. Hopefully, this yeast gets going living and reproducing in the bug mixture before any other nasty microbes can colonize it. If not, bacteria or mold might get going first, and out-compete the natural yeast. It's also possible that some of the ambient airborne yeast in your house might get the bug started... but I think it's more likely from the skin. For this reason, at least when starting the bug, try not to wash the ginger root, at least not too much.

Bottling

• A standard beer-bottle is 12oz, if you fill it to where you're used to seeing them filled.
• Quick math says that a gallon is 128oz, not enough to bottle 2 six-packs, but too much for one
• I like to "bottle" a tester -- a small plastic water bottle, filled part-way with the ready-to-ferment mix. This way, I can squeeze it to detect pressure build-up, and even taste it now and then via the screw-off top.
• Bail-top bottles would be ideal, but I can't seem to find any. Right now, I use standard crown-cap beer bottles.

Recipe

• I like waaaay more ginger. For me, so far, I can't seem to put too much. Spicy is good.
• I like lime juice better than lemon juice; it brings more flavor in addition to the acid/bright flavor, but this is to taste
• I'm starting to experiment with adding things like vanilla extract... no news yet
• I once did it wrong and didn't put in enough sugar. It so happens that on this time I had a particularly vigorous ferment, and all of that sugar fermented out within a couple of days. These bottles were impossible to open without causing a mess... but also, it just was too sour. So, resist the urge to go easy on the sugar, at least on your first batch.

Sugar

As I mentioned, we tried it once with rapadura sugar, which has a very nice flavor. It's basically unrefined sugar, so it has much more of the plant flavor, and probably more nutrients. Note that this is different than brown sugar, which is usually refined white sugar with molasses added back in. This may taste good to you, but the resulting brew will be cloudy and brown, which you may not dig:

We have also tried with palm-sugar / coconut-sugar, which also has a nice flavor. Unfortunately, we didn't get to taste the results, but I'd like to try it again. I'd also like to try with honey or maple-syrup, but am concerned that the natural anti-microbial properties of these may affect the process (though, they do make mead, don't they). Note that not all sweeteners are similarly sweet; for example, rapadura is much bulkier than white sugar and therefore less sweet, so one has to adjust the recipe accordingly. I think honey might be more intense than sugar, etc.

Ginger

In general, in standard grocery stores, one doesn't have a whole lot of choice with regard to types of ginger. I would say, though, that since you're including the skin in the mix, it might be worth buying organic... just to make sure that there aren't any nasty chemicals on the skin from defiled soil.

Yay!

In the annals of our fermentation efforts, Matt and I don't have many stories of non-spontaneous ferments, ferments which need introduced starters to go-- except, of course, kombucha, viili, yogurt...  So OK, a few.  But today I started a new one.  I've been on the lookout for kefir grains, for both dairy kefir and water kefir, for a few weeks, and yesterday, I received a package in the mail from a friendly Brooklynite with water kefir grains (and information and advice) to spare.