Isolating the bugs from Cantillon Kriek

Eureka, another post about a Brettanomyces isolation. Other posts about the same topic can be found here. The beer we are talking about today is the Kriek made by Cantillon. Further information about the Kriek can be found on the Cantillon webpage. Got myself a bottle (bottled on 23 December 2009) and decided to have a look at the sediment of the beer. Maybe some tasting notes first.

Fig 1: Cantillon Kriek

Aroma: Lots of horse blanket and very funky. Could not detect any cherry flavor.

Appearance: Red appearance, pink foam. Some particles from the bottle in the glass.

Flavor: Light fruitiness detectable, right amount of sourness and a bit tart. Pretty neat!

Mouthfeel: Light body, average carbonation level, pretty dry and sour finish.

Overall Impression: Very well made. Although the fruity character is gone. The beer was bottled 2.5 years ago. Maybe the fruitiness vanishes with time? No idea if this is true. All in all a very nice brew. My rating: 95/100. If you can get yourself a bottle. One of the best Krieks I had so far. Although no pronounced cherry aroma.

05/17/12: Streaked some of the bottle’s sediment on a Sabouraud agar plate and incubated it at room temperature.

Fig 2: Cantillon Kriek dregs on Sabouraud agar after nearly 14 days

06/02/12: Colonies were visible on the plate (Fig 2). Only one kind of colonies. Seem to me like very typical yeast colonies. Took a colony from the plate in Fig 2 and re-streaked it on another plate. The colonies now looked quite different as you would expect from normal brewer’s yeast.

Fig 3: Cantillon Kriek yeast on Sabouraud agar after 14 days

Next, look at the colonies under the microscope.

Fig 3: Cantillon yeast

These cells are yeast cells for sure (due to the size and appearance). In my opinion those cells belong to the Brettanomyces species. And they look very similar as the Brettanomyces in Wyeast’s Roeselare Blend (shown here in the pictures at the bottom). Well the cells could be something different than Brettanomyces for sure. However, from the smell of the plate, the look of the colonies on the agar plate and micrograph and the time it took for colonies to appear, I would assign these cells to Brettanomyces.

To summarize, I could isolate Brettanomyces strain(s) from a Cantillon Kriek nearly 2.5 years after it was bottled. The strain goes into my library as B04 (Brettanomyces 04).

The next post concerning a Brettanomyces isolation will be about another Cantillon beer. Stay tuned!

#18P Coffee Stout

Eureka, this is another pilot brew project from 2010. I did a Irish Stout recipe in small-scale and used a share of it to make a Coffee Stout. Coffee is another passion of mine. Luckily for me, Switzerland has a great coffee tradition and a lot of local coffee roasters with many different kinds of coffees. So why not get beer and coffee together for once? I have to mention this is not a new idea. Several commercial breweries produce some fantastic coffee beers already. The recipe below is basically the same as the Irish Stout base recipe. Lets go through the recipe:

Recipe:	Coffee Stout
Numbers:	Volume [L]	5 (1.3 gal)
	Original gravity	10.4°P
	Terminal gravity	3°P
	Color	Around 105 EBC (measured 98)
	IBU	31 IBU
	ABV	3.7 %
Grains:	Pale malt (6.5 EBC)	0.675 kg
	Caramunich 3 (150 EBC)	0.03 kg
	Barley flakes	0.15 kg
	Oatmeal flakes	0.06 kg
	Roasted barley (1150 EBC)	0.085 kg
	Acidified malt (4.5 EBC)	0.1 kg
Hops:	Target (11.5% AA)	4 g and boil for 90 min
	East Kent Goldings (6.5% AA)	2.7 g and boil for 90 min
Yeast:	Wyeast’s	#1084 Irish Ale
Water:	Burgdorf	Mash: 3 L (0.8 gal), sparge: 5 L (1.3 gal) @78°C (172°F)
Rest:		Mash in @66°C (151°F), 90 min @45°C (151°F), 10 min @ 78°C (172°F)
Boil:		Total 90 min
Fermentation:	Primary	5 days @20°C (68°F) in plastic fermenter
	Secondary	None
Maturation:	Carbonation (CO2 vol)	2
	Maturation time	4 weeks

August 2010: Brew day. The procedure of the Irish Stout can be found here. At the end I bottled 0.8 L of the Irish Stout with 0.2 L of coffee (Espresso). I used 10 g of an Espresso coffee and let it steep for some time in 0.2 L of hot water (not boiling) and blended it with the beer after it cooled down. This gives a coffee to beer ratio of about 10 g for 1 L (or 1.3 oz to 1 gal). For the carbonation, I added 10% of unfermented wort to get to a carbonation level of approximately 2 vol. I then left the bottle carbonate for a week at ambient temperatures and let it mature for another three weeks.

October 2010, tasting of the coffee stout.

Aroma: Lots and lots of coffee character. Nothing else. The coffee kind of overpowers the humble Irish Stout base. Although the aroma is right up my alley, I would choose another coffee with more character next time.

Appearance: Black with a nice frothy tan-colored head. Could observe some drops of grease at the surface of the beer. The head vanishes rather quickly.

Flavor: Lots of coffee again. This beer is more bitter than the clean Irish Stout without the coffee. All the other flavors of the Irish Stout get displaced by the coffee flavor. Very similar to a cold coffee.

Mouthfeel: Medium body, lively carbonation, medium lasting sweet aftertaste. No bitter aftertaste.

Overall Impression: Too much coffee character! The coffee just displaces all the flavors and aromas of the Irish Stout base beer. Either decrease the amount of coffee, use a different variety or add it to a different kind of beer. A Russian Imperial Stout could work very well with some coffee. Although, my last Russian Imperial Stout had a lot of coffee character already without the addition of coffee. In addition, consider a technique to get rid of the oils from the coffee to prevent the greasy surface of the finished beer… It looks rather unpleasant.

Did some research in the meantime concerning coffee and beer. It seems there are several different approaches to get your coffee into the beer. One way is to steep the beans in the cooling wort, another one is to soak the beans in cold liquid, add the beans during the boil, yet another one is to add the beans into the secondary fermenter, add them five minutes before sparging… The list goes on. Not to mention several different sources about how much to add. As with many other techniques, there is no right or wrong one to do it as it seems.

I just had a coffee roasted over a coal fire with a very distinct smokiness. A smokiness I have never encountered in a beer before. Another experiment is on the horizon. I will try the cold steeping method and add the coffee to the bottling bucket and add some steeped beans to the secondary fermenter. Maybe filter the cold steeped coffee twice to get rid of the oils. I already see myself throwing some beans in the secondary fermenter and not worrying about the oils and a possibly destroyed head of the beer. Stay tuned!

Dry hopping vs. bitterness

Eureka, its time for another experiment. But not about yeast this time… Sorry! The following experiment is all about hops and their role during dry hopping and bitterness. All started with a batch of Pale Ale where I tried the first wort hopping technique and added some hops for dry hopping (100 g of 14% AA Simcoe to 22 L (5.8 gal)). And the tasting revealed an overpowering bitterness. And some really grassy notes as well. This made me wonder how the bitterness could increase to such a high level in the first place. And there are two possible explanations in my opinion: The first wort hopping technique or the dry hopping. And this experiment was to find out, if the dry hopping can increase the bitterness in some way. Some say that the bitterness only increases when the hops are boiled and the alpha acids isomerize. Others say that the bitterness can increase as well if the hops are not boiled. Lets find out how is right.

What I did was the following: I took a Vodka and diluted it down to have 400 mL of a 5% alcohol solution. I did so to have the same amount of alcohol like you would have it in an average beer. Using pure Vodka could lead to false conclusions since the higher alcohol content could extract different/less/more compounds from the hops. I then added 100 mL of the diluted Vodka to a bottle each and added some Simcoe hops to have the following hops to volume ratio: 4 g L^-1, 8 g L^-1, 16 g L^-1 and 32 g L^-1. Common rates for dry hopping are in the range of 3.9- to 7.8 g L^-1 (according to Calagione Sam mentioned in “Extreme brewing”).

03/02/12: Added 14% alpha acid Simcoe hops to the four bottles according to the mass to volume ratios mentioned above. I stored the bottles at room temperature at a dark place for nearly three weeks before a tasting.

03/22/12: The tasting begun. I first start with the color differences of the liquids. It could be easily observed that a higher amount of hops lead to a darker, more orange pronounced color (Fig 1). Unfortunately, there is a light difference between the two bottles shown in Fig 1 (brighter on the left side). Nevertheless, there was a difference.

Fig 1: Hop infused Vodka, 4 g hops per liter (left), 8 g per liter (right)

Then the tasting. I have to mention first, this was by far the worst tasting ever! I advice you not to replicate these results. It was just horrible. But step by step:

4 g L^-1: At the lower end of the dry hopping rates. Alcohol was easy detectable, very faint hop aroma. Maybe some hints of oranges. And the taste was just bitter. Not overpowering, but bitter.

8 g L^-1: At the higher end of dry hopping rates. More intense hop aroma than the previous one. Very grassy. And the taste was just horrible. Just like eating a hop pellet. And it was definitely more bitter than the previous one as well.

16 g L^-1: Extreme hoping rate 1. Orange notes in the aroma. Floral notes as well. This one is my favorite of the four concerning the aroma. And the bitterness was comparable with the one before.

32 g L^-1: Extreme hoping rate 2. Floral notes, very aromatic hop aroma. The aroma is too intense for my taste. And again, the bitterness is very similar to the one before.

To conclude, the intensity of the aroma increases with the amount of the hops you add for dry hopping. I guess this is no surprise. What I am a bit more surprised is the fact, that the bitterness increases with the amount of hops as well. But only to a level of 8 g per liter of liquid. Further addition of hops does not increase the bitterness. Or at least not in a way that I could taste it. I have to mention here that I am talking about perceived bitterness not IBUs. I have no idea about the IBUs of the four samples.

Lets assume the IBUs of the different beers are the same if we consider that the IBUs originate from isomerized hops. Lets further assume that no isomerization happened during the experiment. How could we explain the increase in bitterness now? One possibility could be the extraction of compounds from the hops by the alcohol present. This would imply that further compound(s) in the hops can increase the bittering sensation. And basically lead to the conclusion that a higher amount of dry hops can increase the bitterness. Not the IBUs but the perceived bitterness.

I assumed that hops for dry hopping could maybe just add a bit of bitterness. But here we are talking about huge impacts. The liquids with the highest amounts of hops tasted like liquid hop pellets… I am still not really convinced here. Maybe this is just something happening only in the used Vodka-based liquids. It is therefore advisable to replicate these results using a fermented barley-based liquid. However, I conclude that a higher amount of hops in a Vodka-based liquid leads to an increasing perceived bitterness (can’t tell if the IBUs increased).

Please let me know if anyone out there has an idea what happened here or if you obtained different/same results as well. Cheers and stay tuned for further post.

Isolating the bugs from Trois Dames Oud Bruin

Eureka, it has been a while since the last post about isolating some wild bugs from a commercial beer. Luckily, there are still some beers in my cellar with bugs I would like to isolate (Orval, Lost Abbey, BFM, Cantillon, Jolly Pumpkin…). The beer I am talking about today is from a Swiss brewery called Les Trois Dames (The three women). This brewery produces an Oud Bruin (Flanders Brown) made with apricot wine. The beer comes with an ABV of 7.2%. Maybe some of my tasting notes first.

Aroma: Sour and funky smell. Pretty awesome! Could detect some cherry notes. In my opinion one of the best smelling beers in Switzerland…

Appearance: Red-brown color, clear appearance, 1 finger tan head with some carbonation. Nothing special here.

Flavor: Now begins the fun part… Unfortunately, the complexity of this beer is very limited. I could detect some sour cherry notes. The sourness is just right. Not too overpowering. However, nothing else. Not even a hint of apricots…

Mouthfeel: Light body, average carbonation level, pretty dry and sour finish.

Overall Impression: There is the right amount sourness in this beer and the aroma of this beer promises a lot. Unfortunately, the flavors speak another language. The beer has a very limited complexity in my opinion. Maybe the beer was too young? Only a second tasting could tell. To summarize, this is a pretty nice beer and because this is a beer made from a Swiss brewery, it is a winner for me for sure. I would give this beer a rating of 85 out of 100. I am a bit disappointed about the lacking apricot notes. I should get myself a bottle of apricot wine one day and compare the apricot flavors there. Maybe the apricot flavors are already very subtle in the apricot wine?

Anyway, this post is about the bugs in the beer. What I did is already a standardized technique for me to isolate some bugs from such a beer. I made myself a small DME (dry malt extract) starter and dumped the dregs of the beer in there and left it for some days. Approximately a month later, I plated some of the starter liquid on some Sabouraud agar plates and waited… Eleven days later, there were some colonies visible on the agar plate (Fig 2).

Fig 2: Sabouraud agar with colonies of Les Trois Dames Oud Bruin bugs after eleven days

The colonies morphology: White, not glossy, wavy margin, convex elevation, circular and the plate had a hint of an acetic acid smell. The acetic acid smell already made me wonder what I got myself here. I then picked a single colony and had a look at it with my microscope.

Fig 3: Les Trois Dames Oud Bruin bugs

Fig 4: Les Trois Dames Oud Bruin bugs

First of all, due to the size of the cells, I assume that all the cells visible in the following pictures are yeasts. I could observe some oval formed cells and some with the mysterious vacuole (Fig 3). And yet again, some cells which adhere to others (Fig 3). For me some of the cells in Fig 3 look like normal brewers yeast (Saccharomyces cerevisiae) and others don’t. Then again, I could observe some elongated cells (Fig 4). I already have an idea about these cells but will have to do further research first. Lets move on to the picture at a higher resolution.

Fig 5: Les Trois Dames Oud Bruin bugs

There are these dark spots again which I could observe in Brettanomyces bruxellensis before (Fig 5). My conclusion from the observations. I assume that I got myself some Brettanomyces bruxellensis and maybe some other Brettanomyces species. Some Saccharomyces cerevisiae could be in there as well. I guess this is all I can tell you about the bugs right now without doing any sophisticated lab tests. Nevertheless, I once again could show that it is possible to harvest some wild yeasts from a bottle. My next steps concerning wild yeasts will be further investigations about the elongated cells as it can be seen in Fig 4. There is a hypothesis in my head what these cells might be and I already found some promising evidence for my hypothesis. Another running project is to isolate the bugs from a Cantillon Kriek. Will post about the results for sure. By the way, the starter I made with the dregs from the Les Trois Dames bugs had no pellicle. Stay tuned for further yeast ranching experiments. Cheers!

#45 Brett in the house

Eureka, todays recipe is about an experiment I planned a while back ago. As soon as I heard that it is possible to ferment a beer only with Brettanomyces (no surprise here since Bretts are yeasts as well), I planned to try this myself: The following recipe is a beer that has been fermented with Brettanomyces only. I split the batch before fermentation and pitched Wyeast’s #5112 B. bruxellensis in one fermenter, and #5526 B. lambicus in the other one. To have some sort of starches left in the fermenter, I decreased the saccharification rest down to 30 minutes instead of the normal 60 minutes.

Recipe:	Brett in the house
Numbers:	Volume [L]	15 (4.0 gal)
	Original gravity	12.5°P
	Terminal gravity	1°P/1.2°P (see description below)
	Color	Around 4 EBC
	IBU	25 IBU
	ABV	> 6%
Grains:	Pilsner malt (4 EBC)	3.0 kg
	Wheat malt (4 EBC)	0.8 kg
	Acidified malt (5 EBC)	0.4 kg
Hops:	East Kent Goldings (5% AA)	40 g and boil for 60 min
Yeast:		#5112 Brettanomyces bruxellensis, #5526 Brettanomyces lambicus
Water:	Burgdorf	Mash: 11 L (2.9 gal), sparge: 13 L (3.4 gal) @78°C (172°F)
Rest:		Mash in @66°C (151°F), 30 min @ 72°C (162°F), 10 min @ 78°C (172°F)
Boil:		Total 60 min
Fermentation:	Primary	11 days @ 20°C (68°F) in a glass carboy
	Secondary	7 weeks @ 15°C (59°F)
Maturation:	Carbonation (CO2 vol)	2 vol
	Maturation time	4 weeks @ 15°C (59°F)

03/03/2012: Brew day. All went according to the protocol above. The starch test was positive after resting for 30 minutes at 66°C. Therefore still some starches left in the wort. Then sparged and boiled for 60 min with the addition of the East Kent Goldings. Then transfered the hot wort into my whirlpool kettle and let the debris settle to the bottom and cooled the wort down to the pitching temperature of approximately 20°C (68°F).

I split the wort in half and filled two 10 L (2.6 gal) glass carboys with approximately 7.5 L of wort (2 gal). Then flooded the carboys with CO₂ and pitched the Brettanomyces. So no aeration of the wort. The Wyeast packages of the Brettanomyces already smelled different. The B. lambicus had a very distinct cherry aroma and the B. bruxellensis a really funky smell.

No signs of fermentation after 24 h after inoculation:

B. lambicus fermenter 24 h after inoculation

B. bruxellensis 24 h after inoculation

03/04/2012: And the fermentation is fully active. A lot of bubbling and a nice kräusen on top of the fermenting liquid.

B. bruxellensis 48 h after inoculation

B. lambicus 48 h after inoculation

03/14/2012: Kräusen vanished. I transfered the glass carboys in my cellar to let the fermentation proceed at a lower temperature (@ 15°C (59°F)).

04/21/2012: Bottled the beers with the addition of table sugar to get a carbonation level of approximately 2.0 vol. The B. bruxellensis finished at 1.2°P, the B. lambicus at 1.0°P. I will leave the bottles at 20°C (68°F) for several weeks to carbonate and then store them in my cellar at 15°C (59°F). The first tasting will be in a few months. So stay tuned.

#10 Agar plates (Wyeast’s Brettanomyces bruxellensis)

Eureka, today yet another post about agar plates and Brettanomyces. This post is about the plating results from streaking some Wyeast’s #5112 Brettanomyces bruxellensis on Sabouraud agar. I first streaked some liquid directly taken from the Wyeast package on a plate and waited for colonies to arise. Then picked a colony after seven days and streaked it on another plate. Lets have a look at the first plate (directly from the package) after six days of incubation (Fig 1).

Fig 1: Wyeast's Brettanomyces bruxellensis on Sabouraud agar after 6 days of incubation

There are some bigger and smaller colonies to be observed (Fig 1). The bigger colonies were off-white colored, milky, raised, even and glossy. The smaller colonies might have formed out of less cells than the bigger ones. So I picked a bit of a big colony a day later and re-streaked it on another plate. I took a picture of this plate after an incubation of eleven days (Fig 2).

Fig 2: Wyeast's Brettanomyces bruxellensis on Sabouraud agar after 11 days of incubation

This time only one kind of colonies could be observed (Fig 2). Morphology like the one before (Fig 1). I added another picture of the same plate (Fig 3). It can be observed that the margins of the colonies get wavy. But the same happens in bigger colonies of Saccharomyces cerevisiae.

Fig 3: Wyeast's Brettanomyces bruxellensis on Sabouraud agar after 11 days of incubation

And yet another picture. The following one is the same plate as shown in Fig 1, but after 18 days of incubation.

Fig 4: Wyeast's Brettanomyces bruxellensis on Sabouraud agar after 18 days of incubation

It’s easy to observe that the smaller colonies in Fig 1, now become bigger ones as well.

As I did other Saccharomyces plates along with the shown ones, I tried to compare the colonies of Saccharomyces and the ones from the Brettanomyces. But I could not observe a real difference in the morphology of the colonies between the yeasts to be able to differ between one and another. For me a colony of Brettanomyces looks like one of Saccharomyces. This could all be due to the agar itself. Other beer bloggers posted about results where they used different types of agar and could differentiate between Saccharomyces and Brettanomyces. One example is BKYeast’s results about selective agar.

The only difference is the time the yeasts needed to form visible colonies. Normally, colonies of Saccharomyces are visible within days (assumed a reasonable amount of yeast is streaked), Brettanomyces colonies were visible after approximately one week. Maybe this can be used to differ between the two yeasts. I should streak the same amount of both yeasts side by side on plates and find out if colonies of Brettanomyces form after Saccharomyces. But now I know at least that Brettanomyces can grow on Sabouraud agar.

If I have some time in the future, I will streak the Brettanomyces on other agar media to try to get a different morphology of the colonies and hopefully be able to have a method available to differ between Brettanomyces and Saccharomyces. So stay tuned!