February 18, 2014

Lambic Solera Update #18 -- Two month into year four (or thirty-eight months into the solera)

I have fallen behind on updating the lambic solera after I brewed the fourth batch going into the fermentor in December 2013 but I am going to get some updates written on this ongoing project while the spontaneous lambic I brewed last month is being less interesting. This update will just review the early fermentation. I'll have to come back around in a week or two to post some tasting notes on the most recent bottling. Normally I try to taste the new lambic bottling around a month after bottling but with the crazy weather last month and this month I've been hit with what feels like a constant stream of bad allergies and a cold. That makes it hard to get really good flavor and aroma analysis out of the beer so I've held off on cracking open Year Three. I did break open a bottle of the gueuze back in December so I'll talk about that here.

First, let's talk about that gueuze. The gueuze was mildly carbonated, which wasn't too surprising. I find sours usually benefit from a few extra weeks of conditioning before the carbonation really sets well in the beer. The flavor and aroma was really surprising. It was very low in acidity and funk. It was almost identical in flavor and aroma to a dry mead. It had a strong honey flavor, which I think was driven by the older vintages but still, where the hell did Year Three go in the mix? Based on my very rough calculations, the blend should have included 40-45% one year old lambic (from Year Three) and from tasting Year Three at bottling there was plenty of acidity. However, none showed up in the gueuze. While it was a tasty beverage it just wasn't what I was expecting. I know gueuze often ages at the brewery for three to six months before shipping out so maybe this is merely part of the evolution of the blended beer that occurs during that aging. I'll probably wait a couple more months before cracking open another bottle.

Alright, so let's talk about this fermentation. If you recall, Year Four was the first time I attempted a turbid mash. This fermentation was definitely different from the prior fermentations. In the past the years with fresh saccharomyces additions (Year One and Three) saw the typical saccharomyces krausen rise within a day or two and after a couple weeks a pellicle would show up. Year Two, which did not have fresh saccharomyces, never showed a krausen. There was just a lot of bubbling from the bottom of the fermentor for several weeks and then a pellicle formed. Year Four did not get fresh yeast but unlike Year Two, there was something slightly krausen-like and plenty of gunk was added to the top of the fermentor. This krausen showed up after almost two weeks after I added the wort to the fermentor and stayed around for a few days. I was starting to get worried when nothing appeared to be going on with the beer but eventually it did kick off. A couple weeks after activity died down a thin, bubbly pellicle showed up.

The aroma changes in the beer during the past couple months was unusual and interesting. In prior years the mix of old lambic and fresh wort had an aroma of lactic acid, cherry and grainy, fresh wort aroma until fermentation knocked out all the fresh aroma and the funky, acidic aroma of sour beer took over. In Year Four it started out with the same aroma but after a few days it developed into a really unpleasant, trashy smell. I started to get concerned. Once fermentation became visible the foul aromas went away and it became very wheat and yeast in aroma. As the pellicle appeared it turned into a combination of the usual sour beer aromas but some of that weird, unpleasant smell remains.

Definitely the most unusual fermentation in the solera's history. I am going to carry on my expectations that this beer will turn out as tasty as the prior years. I will be very sad if the solera takes a turn for the worse and I have to start over. Not the worst thing to have to do but I'd hate to have to choose between drinking or dumping five gallons of crappy sour beer and then waiting another year to get another beer into the solera.

Below is a picture looking down the mouth of the better bottle. You can see the dense layer of junk all the way down and then the very filmy pellicle covering the beer.



February 12, 2014

I Pee, Eh? Black IPA Diagnostic Notes

Brewed in November, I waited on posting tasting notes in hopes that the beer would improve enough I could justify to myself posting a more glowing set of tasting notes. It didn't, so I should go ahead and cough up the admission that I screwed this one up. This black IPA came out of dry hopping with fantastic aroma and flavor. I was really excited for it. Then it carbonated and turned into a total diacetyl bomb. Rather than just put up tasting notes I thought it made more sense, both for myself and for readers, to discuss the problems as well as the sensory perception.

A brief and incomplete overview of diacetyl

In a typical fermentation, diacetyl begins life as acetolactic acid, which is naturally produced during fermentation.It is unavoidable to find acetolactic acid in fermenting beer. It is just something created by the yeast. During fermentation and the clean up period, the yeast will break down the acetolactic acid and the precursors to acetolactic acid and prevent diacetyl from forming, at least at a level that we can taste. It is commonly a failure to perform a diacetyl rest or prematurely removing beer from the yeast that will leave excessive acetolactic acid in the beer. Acetolactic acid then oxidizes into diacetyl, primarily when oxygen is exposed to the beer during transfer or packaging. Once diacetyl is there, it is hard to get it out of the beer. Yeast can break down diacetyl but it is a slow process and in most packaged beer there is not enough active fermentation to get rid of all of it.

However, fermentation conditions can produce more acetolactic acid than the yeast can chew up, such as mutant yeast cells, underpitching, oxygen exposure during anaerobic fermentation, excessive fermentation temperatures, premature flocculation, poor nutrients in the wort, overpitching and pitching at temperatures over 70F. (See http://www.draymans.com/articles/arts/03.html) Even in fermentations where excessive acetolactic acid is created, sufficient contact time with active yeast can often break down enough of the acid to drop diacetyl below the flavor threshold or leave it at low enough levels the beer is still drinkable.

Diacetyl can also be created in beer through infection. Lactic acid bacteria (LAB) like lactobacillus and pediococcus also create diacetyl through their fermentations (think of the buttery taste in yogurt or sourdough bread) well above what saccharomyces can prevent or break down. You can often tell an infection-caused diacetyl problem because other sensory cues will identify the problem, such as acidity, thinness in the mouthfeel, cloudy appearance and other off flavors.


What (likely) happened in this beer

I am fairly confident that this beer did not suffer from an infection. There are no other off flavors in the beer, no unusual cloudy character or excessive carbonation. Additionally, the level of diacetyl has been reducing in the beer. I would expect an infection to continue to chew on the beer and produce more diacetyl. That is clearly not happening.

So that leaves a fermentation problem. I know the beer was properly pitched and aerated like every other beer I brew, so I feel confident scratching out an anomalous fermentation condition as a culprit. What I did with this fermentation is ferment it at 60F with S04, which is very cold for an ale yeast but within this strain's ability to ferment. I chose a cold fermentation to get a clean yeast character and keep as much of the hop aroma from blowing out of the airlock. I fermented the beer for about seven days, cold crashed and then racked off the yeast to dry hop at room temperature for five days. Fermentation was definitely over before racking but I believe the error was not performing a diacetyl rest (by warming the beer) for a few days before racking. Once racked over, oxidation of the acetolactic acid could begin. Why didn't I detect diacetyl in the beer while dry hopping? Oxidation of acetolactic acid into diacetyl doesn't happen that fast. That's why bottle conditioned beer that shows diacetyl almost always goes into the bottle without diacetyl but opens after a few weeks of conditioning with diacetyl.

I would have fixed the problem by warming the beer in a diacetyl rest for a couple of days at the end of fermentation before cold crashing the beer. Easy problem but I got too caught up thinking about preserving the hop character that I forgot about the needs of the yeast. A couple extra days would have been the difference between a great black IPA and a butter bomb.

How the beer turned out

Early on this beer was a total butter bomb but after a few months the diacetyl has toned down considerably. It drinks now like a hoppy English porter with some diacetyl in the background. Disappointingly, the remaining diacetyl muddles the hop flavor and aroma. Diacetyl seems to play better with English hop varieties but among the fruit and pine of American hops it creates sort of a muddled fruit flavor. It's not a great beer by any stretch but at least it is drinkable now. It was really good going into the bottles so the recipe is solid and worth a rebrew.

February 10, 2014

Black Samurai Oak Aged Dry Stout

Why doesn't love a little blaxploitation like Black Samurai? I certainly do. The movie titles are entertaining enough to deserve some homebrews as homage; plus, with How I Met Your Mother ending (a source of many of my brew names) I need to tap a new source for comedic beer names.

This bad mother of a stout is somewhere in the vicinity of a dry Irish stout. It actually began life as a very simple dry stout recipe but while I was working on designing recipes for 2014 I realized I had more spare ounces of grain in the back of my fridge than I thought. So I've tried to shove some of these leftover grains into my recipes this year so I can get rid of them. Here, I added some leftover biscuit malt and carapils. Both additions will add useful contributions to the beer.

I also intended from the outset to do a pseudo-barrel aging on this beer with some oak cubes soaked in Canadian whisky. I thought the drier Canadian whiskey would be a nice touch in a less potent stout. Bourbon can sometimes be overwhelming, plus there are just so many dang bourbon barrel aged beers out there.

That's about all the set up this beer needs. Here comes the 2.5 gallon recipe.

Black Samurai Oak Aged Dry Stout

Batch size: 2.5 gallons
Est. ABV: 3.8%
IBU: 40.6
SRM: 21.9
Est. OG: 1.041
Est. FG: 1.012
Est Eff: 72%

The Grist

3 lb. US 2 Row (2 SRM) 72%
8 oz. Flaked Barley (1.7 SRM) 12%
6 oz. Roasted Barley (300 SRM) 10%
2 oz. Carapils (2 SRM) 3%
1 oz. Black Patent (500 SRM) 1.5%
1 oz. Biscuit malt (23 SRM) 1.5%

The Mash

Single infusion with batch sparge
Mash 6.25 qt 60 minutes at 156F
Sparge 3.11 gallons at 180F
RO water built to black malty profile in Bru'n water

Mash water: 6.25 qts

Gypsum 0.1g
Epsom salt 0.3g
Canning salt 0.3g
Calcium chloride 0.1g
Chalk 0.8g
Lactic acid 0.5ml

Sparge water: 3.11 gal

Gypsum 0.2g
Epsom salt 0.6g
Canning salt 0.6g
Calcim chloride 0.2g
Lactic acid 1.6ml

The Boil

60 minute boil
0.50oz Belma [12.10%] at 60 minutes (40.6 IBU)

The Fermentation

Pitch S-04 at 64F until 90% of estimated FG reached then raise to room temperature. Once fermentation is complete add 0.65oz. Canadian whiskey-soaked oak cubes for 6-8 weeks. Bottle to 2.3 volumes.

Brew day & fermentation notes

Ended up with way, way too much wort. Collected 3.4 gallons in the fermentor, even after extending the boil for an extra hour (before adding hops). Really humid today so that killed boil off and I accidentally added an extra half gallon of sparge water.

Ended up with OG of 1.037 and 3.4 gallons, good for 87% efficiency. We'll see whether the beer ends up too thin or very low on alcohol. Personally I'd rather have less alcohol and enjoy all of the sensory aspects of the beer.

2/15/14: FG at 1.013, good for 3.1% ABV. Added 0.80 ounces (by weight, not volume) of canadian whiskey aged with medium toast oak chips. May add more at bottling to enhance "barrel" flavor. Flavor is good: roasty, chocolate, coffee. Light body, maybe a little too light due to the excess volume. Still expect a very drinkable beer.

3/3/14: Stable FG. Bottled with 2.6 ounces of table sugar. Body is thin but the flavor is nice for a small beer. Lots of chocolate and coffee. Oak tannins show up and the whiskey flavor is mellow and appears strongest in the aftertaste.

February 3, 2014

Spontaneous Fermentation Project Part 7 -- week 4 of fermentation

This week will roll the beer through a month of its journey. Interesting things are going on, although I don't know what exactly is going on, so it's worthwhile to keep recording this journey on a daily basis.

Day 22


You can see the beer still has a cloudy appearance. It's not quite as murky as it was a couple weeks ago but still not a clear beer as you would normally experience in a typical clean fermentation. Even the lambic solera isn't quite this murky although both had the same grain bill and same turbid mash.

Day 23


Here's that mysterious clump floating on the surface of the beer. I still can't figure out what it is. It doesn't look like mold but it seems to be active.

Day 24


If you look at this closer picture, although it's a pretty bad picture, you can kind of tell there's some bubbly foam around the edge of whatever it is. This is the activity that I'm seeing.

Day 25


This is a much better picture. You can see the foam around it more clearly. You can also see off to the right there is another smaller blob. There's actually three blobs.

Day 26


Here you can see all three blobs. They all have that foamy appearance and they are slowly expanding in size.

Day 27

  


Same thing in this picture. I keep snapping pics of the blobs because it's the only visible activity. They are growing. Whatever it is, it's doing something to the beer.

Day 28


 If you compare this picture of the main blob to the beginning of the week or prior weeks you can definitely see it is growing in size.