Tag Archives: dcambic

DCY02 & 03 Test Tasting

DCY02 and DCY03 Test BeersI have been sampling the beer I brewed in April periodically since I bottled in April. With two bottles left of each, it seemed like a good time to write an actual review.

This beer started as a 1.040 pilsner extract wort, hopped lightly with Hallertau only at 60 minutes. Both finished at 1.004, an apparent attenuation of 90%. Consequently, both are a bit thin in the flavor department. But beyond that, they differ quite markedly. The results were quite a surprise.

DCY02

  • Appearance: Very clear, with a pale gold color. The bottle released a lot of CO2 after uncapping. Pouring slowly straight down the middle, it developed a thick, foamy head that dissipated fairly quickly.
  • Smell: Classic Brett funk and phenolic smell. Very lambic-like. A faint background note of fruit, especially strong while pouring. I believe this is the “cherry pie” many have described from Brett beers.
  • Taste: Quite tart. Not a sour beer by any means, but it is noticeably acidic, especially compared side-by-side with the DCY03 beer. Taste is straightforwardly Bretty, hard to find much unique beyond that.
  • Mouthfeel: Surprisingly full, given the high attenuation and low OG. Prickly carbonation.
  • Overall: Not a great beer by any means, but definitely enjoyable. This could be a great yeast for lambic fermentations for sure, and with a more interesting wort could be a good sole fermenter.

DCY03

  • Appearance: Same as DCY02, perhaps a bit hazier for some reason. That is probably sediment from the bottle, not suspended yeast. Poured with large bubbles at first, but eventually developed a thin head.
  • Smell: A bit stronger phenolic note, almost Band-aid-like. Minimal funk, though that may be the other smell masking it.
  • Taste: Bland. Slightly spicy, with a bit of peach in there somewhere. A little tartness, but nothing compared to DCY02’s.
  • Mouthfeel: Quite thin. Due to the sluggish refermentation this may be due to different levels of carbonation compared with the DCY02 beer. The difference is very evident.
  • Overall: A major disappointment, given how nice this yeast smelled in the starter. None of the fruit notes from that stage are present, and the stronger Band-aid note is distracting. It struggled as a refermenter, apparently, as carbonation never fully developed even after months in the bottle. It could be useful as a secondary fermenter (though not as a bottle conditioning yeast) or in conjunction with another Brett strain for primary. I would definitely use a bottling yeast if using DCY03 solo.

I still have one more bottle of each that I will revisit in a few months. Until then, this gives a pretty good indication of what each yeast does.

DCY02 & DCY03: DCambic Isolates

DCY02 and 03 Fermentation in Progress

I am happy to report that isolating the yeasts from The Mad Fermentationist’s DCambic was a success. I have written about it previously and had some issues at first. A lot of stuff going on in life then kept me from the project for a few months but eventually I got the time to get it going again. I have been posting off and on about it on Twitter, but it’s time I document it here.

The key to success the second time was growing a liquid culture first from a sample Mike gave me, rather than plating it straight from the sample. After a few step-up culture iterations I was able to isolate four different yeasts from the beer, instead of just the one I got the first plating attempt. Two were useless for brewing: one is possibly Rhodotorula and the other is another yeast that does not ferment. The others were almost certainly Brettanomyces.

I can tell them apart on a plate because one (DCY02) grows white colonies and the other (03) tan colonies. Liquid cultures are also markedly different: DCY02 forms a pellicle very quickly, smells very funky and drops out fairly quickly, whereas DCY03 takes much longer to form a thinner pellicle, smells very fruity and drops out a lot slower. Taste profiles from the starter are along the same lines as the smell.

I made two simple extract beers in April (1.040 of pilsner DME) and the picture above is of fermentation about two weeks in. They were slow to start but that may be due to low pitching rates. In any case, I have not yet bottled these as they seemed to reactivate after I moved in late May. Perhaps just shaking them a bit roused enough yeast into suspension to do something, and I want to make sure they’re done before I bottle. (I will update this once they are done.)

Strain Descriptions

DCY02: The “white” isolate, based on colony appearance. This has a funkier Brett character with less of the fruity qualities. It produces a pellicle very quickly, and during fermentation produces a thick foam cap that looks more like Sherry flor than ale yeast kräusen. It dropped out of suspension faster than DCY03.

DCY03: The “tan” isolate. This is significantly less funky, and a lot fruitier. It doesn’t produce much foaming during fermentation, and in fact may appear to be doing nothing at all. If shaken, though, there will be a lot of CO2 released. It did not produce a pellicle until several months after pitching and left the wort cloudy for about a month.

Distribution

I hope to have more details soon, both from my beers but also from those of a few brewers I sent samples to. This was also the first time I’ve distributed anything so I kept it limited to four people. However, in the future I will release larger amounts to whomever wants it for a small fee to cover shipping and materials. Future announcements will be made on the blog and on Twitter.

Sourdough Plating #3 and DCambic Update

This is the third and final attempt at plating out the whole sourdough starter. I did a few things differently:

  • I fed the three sourdough starters and let them ferment for 12 hours before starting. Last time two of the starters were right out of the fridge.
  • I put even less of each culture in the sterile water to dilute it
  • I used bromocresol green + potato dextrose plates, plus one potato lactose plate

The rye starter’s plate grew mold in a few days. It totally took over before I had a chance to see anything else growing. The other two starter’s plates plus the lactose plate (on which I plated the wheat starter) were totally fine. I let them grow out for 16 days.

Clockwise from top left: brown rice flour starter, wheat flour starter, wheat starter on potato lactose plate

The colonies look translucent and shiny from certain lighting angles, but they are off-white, smooth and round and actually matte. I did not see any flat colonies like last time. The weirdest surprise is the almost identical growth on the lactose plate. I am going to assume that this is due to whatever sugar was in the potato and not the lactose. My goal in doing so was to see if I could get the bacteria to grow on there and was not expecting the yeast to grow at all. You can see very tiny colonies on each of the plates between the large yeast colonies and smaller yeast colonies. They are transparent and shiny. I believe these are the lactic bacteria.

I think I may not have used enough bromocresol green, or the plates were old enough that it had already started to fade. I was expecting green colonies here, too, but they were white. On my first (recent) attempt I did see green colonies but the plates were also darker back then. The colonies looked quite similar between the two starters. This is a change from the first time I did this (earlier in the year) but could be because I am using a different medium.

I picked out a yeast colony from each and plated it on YEPM medium (recipe from jaapie’s site; the ingredients are not cheap or easy to find for hobbyists like me). In the past, the yeast I isolated from the wheat starter didn’t appear to ferment maltose whereas the rice starter’s did. We’ll see if these grow on it (from what I can tell, yeasts generally but not always can grow on something they can ferment and vice-versa).

On another note, I finally resumed the DCambic project from April. I had isolated a yeast from it back then but it appeared to not do much besides make lots of strong fruit esters. Notably, it didn’t seem to produce any alcohol. This time I instead went for growing it in liquid first instead of plating directly from the sample. I now seem to have two different types of yeast in liquid, judging from the two colors of sediment I see. A darker sediment formed first. I then started shaking to aerate the culture on a regular basis for a few days and then added this to more sterile wort, which I similarly shake on a regular basis. I am now seeing a lighter color sediment forming as well. I also see lots of evidence of fermentation, though I did not see any krausen at any point. I shook up the culture yesterday and streaked a sample on a PDA plate. I’m hopeful that this time I can get the yeast that produces the distinct Bretty aroma I can smell from the culture.

DCambic Update #2

It looks like nothing else is going to grow on the plates, so I went ahead and streaked out one of the colonies on another plate and inoculated a small liquid sample. I will step that up as usual. The plate had a slightly funky smell unlike any yeast plates I’ve dealt with so far. The colonies also look bigger, glossier and more irregular than others I have dealt with. I have not yet worked with laboratory Bretts, though, so I can’t compare. In any case, given that the previous liquid sample grown from the raw beer developed an intense Bretty character I am quite sure that is what I’m dealing with here. I’m not too good at describing the various Brett flavors, so I’ll venture only that it is fruity and phenolic. Although there was no visible fermentation there is definitely alcohol in the aroma. I am imagining the new liquid sample from the pure culture will smell the same.

I had originally planned to streak out two plates, one with potato dextrose and one with potato lactose, but I ended up not having the time to prepare them this weekend. I went instead with another malt extract plate. This doesn’t help me get any new information on how the strain behaves but it’ll do for now. When I have the time I will prepare those potato plates with bromocresol green and restreak. One nice thing about potato media is that you can easily swap the sugars and make different types from the same batch of potato infusion.

Nothing at all grew on the brilliant green plate. My previous experiments with them had at least some yeast growth but it was very slow. This time I don’t see anything. It is safe to say my experiment with that medium is a failure. Good thing it was unnecessary for this experiment.

DCambic Plate Growth

It’s now been about a week since I plated the DCambic sample. A few days ago I began to see growth of what appear to be yeast colonies growing on the malt extract plate. They are round with small peaks in the middle, and appear to be a little glossy. It’s hard to tell right now because I am not opening the plates just yet to avoid contamination. I want to leave these out for at least three weeks to allow any slow-growing organisms to appear.

There is also some yeast growth in the liquid sample. I began to see a layer of sediment a few days ago. No pellicle or visible signs of fermentation, but the pH dropped to the mid 4 range (using strips to check) and there was a somewhat Bretty aroma. There is a little funk but the dominant smell is sort of fruity, not unlike canned peaches. I am stepping that up to 250mL as we speak.

Once I’m done with incubating I will streak out the individual organisms and grow them in liquid. It’ll be interesting to see if I get the same characteristics as in the current liquid sample.

DCambic Plating

Last week Mike the Mad Fermentationist gave me a sample of his spontaneously-fermented DCambic. I had just made some brilliant green agar plates, from BKyeast’s excellent post on media. This media is antibiotic, killing most types of bacteria while allowing yeast to grow. My first thought was to plate some sort of lambic, hopefully being able to isolate the yeasts present. I figured what better lambic than a local one, and Mike was kindly willing to give me a sample.

For this plating I did my first serial dilution. I had previously only done streaking using a needle, whereas this involves placing a small amount of dilute liquid and spreading it around the whole plate. I diluted it 1:1000. I picked that factor somewhat randomly. I was planning on doing at least 10^6 as I had read somewhere, but since I was starting with a clear beer sample and not the dregs, I figured it wouldn’t need anywhere as much dilution. I had previously prepared vials with 9mL of distilled water, so I just had to pick three of these vials. I added a small amount to a brilliant green agar plate and a simple malt extract agar plate, and spread it around with a cell spreader (“hockey stick”). At the same time I also added about 5mL to 50mL of sterile wort to see what would grow in liquid media.

I did this on Saturday, and as of today, Tuesday, there is nothing growing yet. The plates are clean, and the liquid sample is still clear. I am afraid I made a dumb move and tried to do this after the sample had settled in the fridge, without shaking it up. If nothing grows soon I will try plating again. I already added another 5mL of the shaken-up sample to the liquid. Hopefully there will be some growth there soon. In any case, I will definitely post updates as this goes on. Who knows, maybe I’ll be able to isolate an interesting Brett from it. I would also love to isolate the saccharomyces that did most of the fermenting, though there might not be any more in suspension at this point.