AG#13 : Belgian Dark Strong Ale

[MacKiwi]

This brew is part of a project that the Scottish Craft Brewers (http://scottishcraftbrewers.org/), of which I'm a new member, are running. Basically, everyone brews the same recipe, expect that everyone is allocated a different yeast to use. I was given Wyeast 3522 - Belgian Ardennes. The plan is to drink them at the next get-together and see what affect the various yeast strains have.

The yeast came in a "smack pack", which I hadn't used before. Quite fun giving it a slap and then leaving the pack to swell up. I then pitched that into 2 litres of wort to (hopefully) double it, as the beer is a little on the strong side for the number of cells in the original pack.

Obligatory grain shot. This is the first time I've used Special-B. It smells great!

The mash went fine. I tried recirculating the wort at the end using my pump to set up the filter bed, instead of using a layer of tin-foil and returning it with a jug. I'm not sure if this was any better or not, but I saved a bit of tin-foil :)

I had to sparge a little longer than normal, and boil for 90 mins instead of the specified 60 mins, to get to the target 1070 OG. The result was 16 litres of wort in the FV.

Lots of lovely hops too. Anyone ever had to explain the contents of these brown paper bags to a policeman?

I then deployed my new high-tech wort aeration device...

Fermentation started very quickly (12 hour lag). The result of the aeration, or a good starter?

I've transcribed the recipe provided into Brewmate...

Belgian Dark Strong Ale

Recipe Specs
----------------
Batch Size (L): 21.0
Total Grain (kg): 5.800
Total Hops (g): 100.00
Original Gravity (OG): 1.071 (°P): 17.3
Final Gravity (FG): 1.016 (°P): 4.1
Alcohol by Volume (ABV): 7.22 %
Colour (SRM): 11.8 (EBC): 23.2
Bitterness (IBU): 30.7 (Average)
Brewhouse Efficiency (%): 80
Boil Time (Minutes): 60

Grain Bill
----------------
4.000 kg Pale Malt (68.97%)
1.000 kg Munich I (17.24%)
0.400 kg Cane Sugar (6.9%)
0.200 kg Special-B (3.45%)
0.200 kg Wheat Malt (3.45%)

Hop Bill
----------------
90.0 g Saaz Leaf (3.1% Alpha) @ 60 Minutes (Boil) (4.3 g/L)
10.0 g Saaz Leaf (3.1% Alpha) @ 5 Minutes (Boil) (0.5 g/L)

Misc Bill
----------------

Single step Infusion at 64°C for 90 Minutes.
Fermented at 18°C with Wyeast 3522 - Belgian Ardennes

 

[adrianmole72]

That looks good - will it make much difference if I were to use M.O. instead of pale, as I've got a big sack of that ?

Stephen

 

[MacKiwi]

I'm sure you could. I was given the ingredients, otherwise I would have used my big sack of MO too :)

 

[WelshPaul]

I had to sparge a little longer than normal...

Do you have the exact details of this part as it's the step in AG brewing that I am always a little vague about.
I always batch sparge at around 75-77°C for 10 minutes or so but I'm always a bit unsure over exactly how much sparge water to use, how long to leave it for and at what point to stop the run-off.

 

[wilsoa1111]

sounds like a solid test- i read someone else doing this in brew like a monk, gave some interesting results and would be interested to see how urs compared to theirs...
"White suggests that homebrewers needn’t wait for those results. “I think homebrewers would do best by sensory analysis, with side-by-side fermentations,” he said. In 2001 the Great Northern Brewers Club of Anchorage, Alaska, conducted an experiment in fermenting tripels with yeast as the variable. Club members brewed a 1-barrel batch and split the wort into six carboys, adding different yeast to each one, then fermenting and conditioning them identically. The brewers collected empirical data along the way, then tasted the finished beers blind. All beers fermented for eighteen days at 70 to 75° F (21 to 24° C), which was not necessarily ideal for some of the yeast. Beers spent more than three more months conditioning and lagering.
Wyeast 1056 (American Ale Yeast) acted as the control yeast, and working in a wort rich with candi sugar (more than 10%) and at a higher fermentation temperature than usual had a stunning apparent attenuation of 87.8%. The 1056 beer finished last in sensory evaluations, not surprisingly lacking in Belgian characteristics. The group found, “Alcohol overwhelms all other flavors, finishing dry and harsh. Minor modifications to the recipe and lower fermentation temperatures would have produced a nice blonde barley wine.”
The two yeasts not widely available, Brewtek CL-320 and CL-300, rated highest in sensory tests. The Brewing-Science Institute in Colorado (www.brewingscience.com) sells them to homebrewers on plates and to commercial breweries in pitchable quantities. Both earned praise for their complexity and low production of higher alcohols.
Somewhat surprisingly, neither Wyeast 3787 nor Wyeast 1762 attenuated nearly as well as they do in the Belgian breweries from which they came, or at several American commercial breweries that use the strains. The results simply confirm the importance of treating each of these yeasts individually when considering everything from pitching rates to fermentation temperature.16
When Wyeast and White Labs provide guidelines for apparent attenuation, they base them on all-malt beers, usually not fermented at the top of the suggested temperature range. Beers with sugar providing more than 10% of their fermentables will attenuate further, and further still at higher temperatures. “It’s really important that brewers let them reach terminal gravity,” Logsdon said. “I have heard too many brewers who say ‘I’m going to stop it here,’ because they’ve calculated what the attenuation should be. The worst thing you can do is get incomplete fermentation.”
Tradeoffs: Higher original gravity produces more esters, as does higher attenuation. More aeration lowers ester production. Belgian yeasts naturally produce more esters, including some related to wheat yeasts. Logsdon notes, “Fusel alcohol raises perception of isoamyl acetate. It wasn’t detected as strongly when fusels were lower.”

 

[joe1002]

One of the other brews is being done by Kev, see here. I wonder whether any of the other brewers are on here?

 

[MacKiwi]

I had to sparge a little longer than normal...

Do you have the exact details of this part as it's the step in AG brewing that I am always a little vague about.
I always batch sparge at around 75-77°C for 10 minutes or so but I'm always a bit unsure over exactly how much sparge water to use, how long to leave it for and at what point to stop the run-off.

I'm fly-sparging, so there is a bit of a difference there. But what I was doing was measuring the strength of the runnings, and at the same time monitoring the strength and quantity of the wort in the boiler. I knew what the target OG was, and I have a rough idea how much my boiler concentrates the wort as it evaporates water, and at one point my calculations were showing that I was going to have to boil for an unacceptable period of time (>90 mins) to get there (normally I have to liquor back at the end, but with a beer this strong it's a different story).

So I slowed down the sparge to get the most sugar out, whilst monitoring the runnings to make sure they didn't drop below the point where you start extracting tannins. This did the trick, and I managed to get enough sugar into the boiler so that after 90 mins of boiling the gravity was bang on target.

Luckily I had a friend helping so I could do the calculations - it would have been a bit frantic otherwise.

I'm still trying to dial this in too. The above shows I'm not yet a master of my equipment. I think with fly-sparging you get a bit more wriggle-room, and can monitor things as they progress. I'm not sure how this would translate to batch-sparging.

 

[WelshPaul]

So I slowed down the sparge to get the most sugar out, whilst monitoring the runnings to make sure they didn't drop below the point where you start extracting tannins. This did the trick, and I managed to get enough sugar into the boiler so that after 90 mins of boiling the gravity was bang on target.

This is one thing that tends to confuse me - when batch sparging, is it best to stop when the extracted wort hits a gravity of 1010, or should it be stopped earlier?

 

[MacKiwi]

Yep, that is the general rule of thumb I follow too. Of course, you need to temperature adjust - the runnings from the mashtun may be 60 degrees, in which case the value you'll be reading with your hydrometer will be 995.

I find if I fly-sparge slower, I get slightly better extraction, and I can get a bit more wort out before the runnings drop below 1010.