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!

#12 German Ale

Eureka, time for yet another recipe from my first experiences as a homebrewer. This is a recipe I did back in 2009, a German Ale style beer fermented with Wyeast’s #1007 German Ale yeast. Pretty easy grist, mash schedule and fermentation. Lets go through the recipe:

Recipe:	German Ale
Numbers:	Volume [L]	19 (5 gal)
	Original gravity	12°P
	Terminal gravity	3.3°P
	Color	Around 10 EBC
	IBU	19 IBU
	ABV	5 %
Grains:	Pilsner malt (4 EBC)	0.38 kg
	Vienna malt (8 EBC)	3.9 kg
	Carapils (4 EBC)	0.1 kg
	Acidified malt (5 EBC)	0.1 kg
Hops:	Hersbrucker (3.2% AA)	37 g and boil for 90 min
	Tettnanger (4.1% AA)	22 g and boil for 80 min
Yeast:		#1007 German Ale
Water:	Burgdorf	Mash: 18 L (4.8 gal), sparge: 15 L (4 gal) @78°C (172°F)
Rest:		Mash in @45°C (113°F), 20 min @ 43°C (109°F), 30 min @ 63°C (145°F), 30 min @ 71°C (160°F), 10 min @ 78°C (172°F)
Boil:		Total 90 min
Fermentation:	Primary	7 days @ 20°C (68°F) in plastic fermenter
	Secondary	None
Maturation:	Carbonation (CO2 vol)	2.5 (bottled at 4.7°P)
	Maturation time	> 3 weeks

05/01/09: Brew day number twelve begins. All went according to the recipe above. Nothing to mention here.

05/07/09: Bottled the beer with a gravity of 4.7°P. The forced fermentation test finished at a gravity of 3.3°P. There should be enough sugars left for the appropriate carbonation level. The pressure gauge I used to check the carbonation level showed a pressure of about 2.05 bar after a few days into the bottle fermentation. This is equal to a carbonation level of approximately 2.5 vol of carbon dioxide.

I have to mention here, that I did several batches where I bottled the beer just at the right time to have enough sugars left for the carbonating process. Now I just add sugar or even unfermented wort. This is far easier than waiting for the right time to bottle. Another thing that I do differently today is the time for fermentation and secondary fermentations in the first place. I did no secondary fermentation steps back then. Now I leave the beer for another two weeks in the fermenter to let it clear and finish the fermentation.

No tasting results for this batch. Sorry for that. I must have lost them… From the grist I would expect a rather malty beer (due to the high amount of Vienna malt) and a rather subtle hop character. If someone else out there gives this recipe a go please let me know how it turned out.

#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!

Tasting: #44 Traditional Berliner Weisse

Eureka, its time for another tasting post. Today is all about my first Berliner Weisse. I brewed my batch (#44 Traditional Berliner Weisse) back in February 2012. I went with a traditional grist (Pilsner and wheat malt) and did a spontaneous mash-souring. So no addition of any Lactobacillus or any other bacteria. Did a primary fermentation with a classical European yeast (Wyeast’s #1338 European Ale) kegged one share and bottled a small part of the batch with some Brettanomyces I isolated from a beer made by BFM. Nearly four months now passed since the bottling. Lets see how the beer in the bottle (with Brettanomyces) turned out. By the way, the share without Brettanomyces in the keg is very similar to this one although not as sour and complex. Therefore no tasting notes about the share without Brettanomyces.

Aroma: Very lemony and lots of apples. Some sourness detectable (lactic acid). Some funkiness as well. Very similar to a cider. Smells clean.

Appearance: Yellow, cloudy, white head, lots of carbonation visible.

Flavor: Not a lot of flavors. There is some sourness detectable. Some hints of grains (malty-, breadyness). And again some apple notes as well. All in all very similar to a cider. Maybe the sourness in the Weisse is just a bit more powerful than in a cider.

Mouthfeel: Light body, lively carbonation, medium lasting malty/bready aftertaste. No sour or astringent aftertaste.

Overall Impression: What shall I say. Looking back, I would not have guessed it would turn out like this. This is a very drinkable beer indeed. Some notes of a wheat beer (grainyness, head) but with some sourness attached. For my taste, the sourness level is a bit too low. However, this recipe was not about the right level of sourness. It was about the spontanteous sour-mashing technique. In my opinion, this worked completely. All the Berliner Weisses I had from this batch were ok. Nothing to complain about.

My next Berliner Weisse is already in the pipeline. Just got my #3191 Berliner Weisse blend today and a Berliner Weisse brew day is in the near future. I just have to wait to get some empty bottles… (And I am already working on it…). And I already planned to isolate the Brettanomyces from the blend (my longtime followers will already have guessed…).

This was a very interesting and very informative experiment in my opinion. Not only is it possible to make a beer without ever boiling it, but it is also possible to use the microorganisms on the grains to sour a beer. A very neat way in my opinion to get yourself a sour beer if you do not want to purchase any souring bugs. However, comparing the Berliner Weisses with and without Brettanomyces, the one without it is clearly less sour. Brettanomyces seems to enhance the sourness level as well. From now on, all my Berliner Weisse brews will have some Brettanomyces in it, like a traditional Berliner Weisse.

This post closes another experiment of mine. Stay tuned for further experiments!

Beer color estimation by use of a DIY spectrophotometer

Eureka, the following post is one I am really proud of. It took me some time to build the device and calibrate it. But it seems to work. I am talking about a self-made spectrophotometer to estimate the beer color. Isn’t that cool? I have to say that the measurements are more an estimation than a measurement. However, the precision is good enough to get an idea about the color. Of course there is the possibility to estimate the color of a beer with a kind of chart. I have one of my own. But I always wanted to build myself a spectrophotometer and why not build one for measuring the color of beer. I will shortly talk about the build up and then go into the calibration I did a while ago.

Preparation

I build myself a spectrophotometer as described here. Unfortunately, the descriptions are all in German. But the most important part, and I guess the only one I used from the cited page, is the circuit diagram. The cited page describes how to build a spectrophotometer for measuring nitrate in the water of an aquarium. The only difference to my spectrophotometer is the different LED. I used a 430 nm LED to measure the beer color. To determine the color of a beer, you measure the absorption of the sample in a 1 cm cell at a wavelength of 430 nm. You then multiply the absorption by 25 to get the color in EBC. In my case, I calibrate the spectrophotometer to assign the measured voltages to a EBC-value. Further information about the EBC can be found on Wikipedia.

Building the spectrophotometer

First of all, I do not fully understand the circuit diagram (although it is explained on the cited page). Please do not ask any questions about the circuit. I just ordered all the parts I needed and built the circuit.

Maybe some explanations about the circuit. I used a 12 V power supply unit for the power supply. The red LED (= LED3 rot) is for the “power on” sign. As already mentioned above, I substituted the second LED (LED3 grün) with another LED (emission wavelength of 430 nm) to measure the EBC’s. The light dependent resistor’s (LDR) task is to measure the light from the 430 nm LED after passing through the sample (marked as M). At the end, the resistance from the LDR is transformed into a voltage and measured with a voltage meter (indicated as V). The two linear potentiometers are there to adjust the voltage (for example to adjust the offset).

The next picture might be cruel for people in electronics… I am not very good in soldering and electronics. Luckily for me, I do not have to make money with my bad soldering skills. However, I managed to build this whole device.

Fig 1: Inside the spectrophotometer…

At the bottom of the box is the circuit board with all the connections to the parts such as the red LED (power) and the two linear potentiometers on the cover of the box (Fig 1). The measuring cell is implemented in the wooden block.

Fig 2: Measuring block with LED and LTR

The measuring block consists of two wooden parts, an upper and a lower one (Fig 2). Both parts have a hole with a diameter of 12 mm for the measuring cell (Fig 3). In the block itself are the LED (emitting light at 430 nm) and the LTR (collecting the light coming through the sample). The LED is on the left side of the block, the LTR on the right side (Fig 2). Unfortunately, I do not have any pictures of the inside of the block. However, if you stick the measuring cell in the whole, the LED shines light into the measuring cell and on the direct opposite side of the LED is the LTR collecting the light coming out of the measuring cell. Simple as that.

Fig 3: Cell to measure the sample (12 mm in diameter, total length 100 mm)

And now some pictures of my device how it looks like at the end and during a measurement.

Fig 4: Spectrophotometer ready to measure

You basically connect a voltage meter to the spectrophotometer, insert the measuring cell, adjust the voltage at the beginning (offset and blank) and off you go. In theory, the voltage you measure depends on the color of the beer. Lets see if the spectrophotometer really works.

Calibration

The first test of my spectrophotometer was a calibration with commercial beers. I found a list where someone measured the color of different commercial beers. I used: TsingTao (5.91 EBC), Pilsner Urquell (11.62 EBC), Anchor Liberty (22.26 EBC), Anchor Steam (31.52 EBC), New Castle Brown (56.54 EBC), Samuel Smith Nut Brown (61.46 EBC) and Guinness Draught (92.39 EBC).

I first filled a measuring cell with water and adjusted the voltage with the linear potentiometers to 1 V (blank and offset). Then filled the beers in the measuring cell and collected the voltages for each sample. I have to mention, the spectrophotometer only works with clear samples.

Results

The calibration with the 1 V offset showed a linear correlation between the measured voltage and the color of the sample (Fig 5).

Fig 5: Calibration curve with 1 V offset

I did two different calibration with different offsets. For the second calibration, I used an offset of 2 V. The slope of both calibration were very similar (0.071 V EBC^-1). Further information from the calibration:

– Detection limit: 10.6 EBC

– Measure Anchor Steam (31.52 EBC) gives 35.6 EBC (SD = 2.23 EBC)

– Measure Guinness Draught (92.39 EBC) gives 95.1 EBC (SD = 4.04 EBC)

The measured values of the both beers are significantly different from the stated values. However, this is by far good enough for me. I do not need an exact EBC value anyway. On the other hand, my device can’t measure samples with an EBC value lower than 10.6 EBC. No problem here, I do not brew such light-colored beers…

Discussion

The calibration showed a linear correlation between the measured voltages and the color of the calibration beers. And this proves to me that my spectrophotometer can be used to measure (or estimate) the color of a beer in a rather easy way. I stick to estimate rather than measure.

I have to be honest, I never expected this to happen. Before doing this calibration I had to make an assumption: The color of the commercial beers I used were exactly the same as stated in the list. Differences in colors of the different batches should be very minor. In addition, the values stated in the list were true. I assume the differences from the linear fit curve to the measured values could be due to differences to the stated values. Nevertheless, it worked!

To test if this device really works, another calibration would be necessary. This time, measure the values of the different beers with a lab spectrophotometer at 430 nm and determine the voltages with my spectrophotometer. Maybe an experiment for the future.

I did this calibration a few years back and used my spectrophotometer just once. However, I build this device to understand the concept of a spectrophotometer in the first place. Now I know how such a device works and even have a tool available to estimate the beer colors.

#17P Irish Stout

Eureka, its time for yet another recipe from the past. Today’s recipe is my second attempt to brew a traditional Irish Stout recipe. My first attempt to brew such a beer resulted in a sour beer and a lot of disappointment. It took me nearly four years after my first failed attempt to brew another Irish Stout. To prevent another full sour batch, I chose to brew a small batch of 5 L (1.3 gal) instead.

One advantage of small batches is the smaller amounts of grains you need, less heating time and increased variety of beers you can make. However, there are some disadvantages that made me switch back to full batches. Even for experimental ones. One big disadvantage in my opinion is the lower efficiency I get with small batches. I have no problem with lower efficiencies in general. I just don’t like it when my calculations are not correct… I created a very sophisticated spreadsheet which fits perfectly for my full size batch size system (20 L, 5.3 gal). The original gravity and volume I now calculate with this spreadsheet is very close to what I measure after a brew day. This is very important in my opinion since I do have to prepare the yeast prior to the brew day. Another disadvantage of small batches is the time you need to make a small batch. In my experience the time you need to make a full batch is just a few hours longer than doing a small batch. However, this is just my experience about small batches. I just like to do big batches…

Back to the recipe. The grist is very typical for a Stout. Maybe the oatmeal flakes are not very typical. Lets go through the recipe.

Recipe:	Irish 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 @66°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, small batch day. The batch size was so low, I could even use a normal pan to do the resting. Iodine test was negative after the rest at 66°C (151°F). Did a fly sparge and boiled the wort for 90 min with the hops. Then cooled down the wort and pitched Wyeast’s #1084 Irish Ale yeast. Original gravity of 10.4°P. Lower than expected…

Gravity down to 3°P after five days of primary fermentation. Bottled the beer with some leftover wort and left the bottles carbonate for a week. Used half of the batch for a coffee stout. Then left the bottles in my refrigerator for nearly four weeks.

October 2010: Tasting:

Aroma: Hoppy and some chocolate notes. Not a lot of roastyness.

Appearance: Black appearance, creamy tan colored head with very tiny bubbles.

Flavor: Big chocolate and roasty character. Some hoppyness detectable and some maltyness as well. Rather nice.

Mouthfeel: Light to medium body, lively carbonation, short and sweet aftertaste. Very watery though. Easy to enjoy anyway.

Overall Impression: Very refreshing and I could not detect any off-flavors. Really like the way this turned out. Although, for my taste, the beer should have more body to counteract the watery sensation. I slightly changed this recipe for the next, third, Irish Stout batch. Will post the coffee stout recipe in a few days. Stay tuned!