Checking in on the recently filled lambic barrels

Last weekend I went up to check on the barrels from our brew day a couple months ago.  Given that this was the first time using a coolship, I was a little anxious to see how they were doing.

Taking a step back, I realize I haven't written anything about the brew day itself.  It was a full weekend and somehow everything went off without a hitch.  There is a great write up here summarizing the weekend better than I could.  The brewers at O'so have got the process down and are very efficient at doing what they do. Compared to previous years (which I have notes posted), there is very to add regarding the brewing.  Post-brew however, the wort went from the boil kettle to the coolship that had been temporarily installed outside under a large tent to rest overnight.

Coolship filling with lambic wort.  (photo credit)

From literature on the process, I was hoping the wort would be ~70°F the next morning.  We got in around 8:30 am and checked it with a digital thermometer which read 70°F exactly.  I was ecstatic to say the least. The inoculated wort was then pumped into a large tank to ensure everything was homogeneous, and then pumped into barrels.  Some of the barrels filled were straight from the winery and some of the barrels filled were previously emptied lambic barrels.  They were all thoroughly cleaned out with 200°F water prior to filling.

So, back to being up there and checking in on the barrels.  I was able to taste from barrels that had previously held our lambic, but the barrels that were our first use were tucked away such that we couldn't get to them without a forklift.  There was an event going on at the brewery, so I'll wait for another day to check in on those.  I am curious to see if there will be a distinction between the two sets of barrels.

I am a firm believer that, while a coolship imparts a new generation of microflora into the wort, much of the fermentation process is guided by the yeast/bacteria already in the barrel.  Cleaning the barrel, even at the high temperatures we do, will never sanitize the barrels completely and yeast/bacteria residing deeper in the wood will survive.  Through generations of culling barrels, a brewery is able to build a "house flavor".  You will find others who argue the relative impact of the coolship on the fermentation process is greater than that of the barrel.  Its an interesting argument if you really like nerding out about this stuff, and having these two sets of barrels is my way of testing things out.

It was interesting to taste the barrels that were accessible.  At this age there is little you can tell about how the beer will turn out, but I am able to see if its "on track".  First, I am making sure it did in fact ferment instead of spoil.  Given this was the first time spontaneously fermenting via coolship, that concern was lingering in the back of my mind.  But everything checked out.  It actually tasted almost exactly as the previous year's barrels did at this point.  It has a light tartness and an ever so slight brett character. The only difference I noticed from prior batches was there was a sweet lime flavor.  Is this an impact of local microflora?  In addition to these flavors, there is this phenolic flavor which we've noticed in previous batches as well. Its just an odd stage our lambic goes through. The reason I mention this is so home brewers who may be reading this know that these early off flavors are not a reason to dump your beer.  Honestly, there is no reason to even taste your lambic in the first 9 months.  I just do it for fun and because I can pull out of a sample port below the pellicle line.

Barrel Notes: Day 277

Just a quick update as I had to open the barrel to take a measurement of the bung.  While it was open I decided to snap a picture:

Lambic pellicle at day 277.

And wow!  It smells amazing.  It smells like it would be very good to drink already.  I've always seemed to be pretty good with the patience and waiting game, but this is going to be tough.

Barrel Notes: Day 102

The main point of this update was to check on the pellicle.  As I mentioned in Barrel Notes: Day 60, the pellicle had appeared to be clearing up.

To recap, here is the progression of the pellicle:

Day 17

Day 22

Day 34

Day 60

And now today:

Day 102

It appears that things are starting to develop again on the surface.  I'm still not sure what is going on.  I like that it appears to be forming a pellicle again as I intend to age this barrel for 3 years and a strong pellicle will help cut any O2 exposure in the head space.  I spoke with Vinnie at Russian River before I got home today, so only had the first 4 pictures to go off of.  He had some good things to say, but no real definitive "this is what's going on" answer.  He recommended asking the folks on Babble Belt, so that's what I'll do.  Feel free to read and join in on the conversation over there.

I didn't take a sample out this time, but it smells fantastic...

Barrel Notes: Day 60

Wow, already 2 months in.  Last time I took a gravity reading was Day 9, so I thought the 2 month mark was a good time to do it again.

Gravity reading: 1.010

This is about what I expected.  What I didn't expect was the color of the beer.  If you compare that to when I got the wort (far right in this image), you can see there has been a huge change.  It use to be dark brown, and now is orange.  I wasn't sure why this happened, so I asked expert home brewer Jay (aka Fear025):

The wort was dark because there were caramelized particles suspended in the liquid. As time passed, gravity pulled those particles downward to settle at the bottom of the vessel.

Pretty simple answer really.  I wasn't really worried about the color, but it is nice to know it will clear up to a more traditional lambic color.

Now on to the pellicle, here is a picture of it from today:

This I find odd.  Compare that picture to the image from Day 34, and then to the one from Day 22.  Its almost as if the pellicle is clearing up.  I have read that the brett will eat the pellicle, but I thought that is something that would occur very late in the aging process and at a minute scale.  Any ideas as to what is going on?  The only other thing I can think of is that the weather has been very warm lately, which should have kicked in the pedio stage.  Is this the beginnings of my beer turning "ropy"?  I hope so!

Barrel Notes: Day 34

Checking in on the pellicle again.  Here is how it looks:

Comparing that to the previous picture, the pellicle has gotten denser over the last couple weeks.  The aroma hasn't changed much, but I am getting a bit of an almost tropical fruitiness.  Still very funky and still quite a bit of lacto.  It's encouraging to have a wide range of aromas already.

Barrel Notes: Day 22

I have checked in on the pellicle again as I am interested to see it during different stages of development.  Here is a picture of its current state.

As compared to the picture in my previous post, it appears as if little colonies have developed.  The aroma coming from the barrel is increasingly funky.

You may remember that in addition to the 225 liter barrel, I had enough wort left to fill a small 5 gallon barrel.  To ferment the 5 gallon barrel, I used an assortment of commercial sour dregs collected at a beer tasting event.  It is interesting to compare the pellicle formed in the big barrel (above) to that of this 5 gallon barrel (below).

There are a few major factors that cause such a different pellicle formation between the two barrels.  The primary factor would be the different yeast source.  Another factor is the 5 gallon barrel has higher oxidation due to greater surface area with the oak.  In addition, there was only about 4 gallons remaining to fill the 5 gallon barrel, so it is a relatively short fill resulting in a larger head space.  This head space has theoretically been filled with CO2 during the primary fermentation phase, however I do not doubt a certain amount of oxygen was present as well.

I don't want that much head space in the 5 gallon barrel during the aging process.  After some consideration on what to do, my plan for this 5 gallon barrel is to make the Sikaru I talked about earlier.  To do this, I will be adding dates and honey to the lambic.  The rule of thumb in fruiting lambic is 2lbs of fruit per gallon of lambic, so I will be requiring 8-10 pounds of dates.  Normally fruiting is done a few months prior to bottling, however, I will be adding a portion of the dates now to eliminate the unwanted head space in the barrel.

I purchased 4.5 pounds of whole dates.  I'm not 100% sure the reason behind using whole fruits, however I know Cantillon and others insist on it, and so I made sure to follow suit.

I wanted to wait until primary fermentation had ended to add the fruit, but make sure they were added before the aging stage started.  With the amount of sugar in dates, and the amount of dates I added, I wouldn't doubt if I saw a reasonably strong second fermentation.  I'm not worried that I've damaged the existing pellicle (and of a second fermentation damaging it further).  It was not dense enough to fall, and the disturbed area will grow back in short time.

Barrel Notes: Day 17

I can't help buy go down and smell the barrel every couple days (the aroma had been gradually declining since that Day 4 post).  It has been a few days since I have checked in on the barrel, and not expecting much I was surprised by the burst of new aroma.  Its still got a sour note, but now there is some funky aromas going.

I grabbed my flashlight to see how it looks, and to my delight, a thin pellicle has formed!

Those of you follow this blog know what a pellicle is, and know its a crucial part of the lambic brewing and aging process.  This is sooner than I expected the pellicle to form, but honestly I didn't know when to expect it.  I am going to declare the primary fermentation as complete and bung the barrel.

Barrel Notes: Day 9

While installing the sample port yesterday, I took a bit out to measure the gravity and see what it tastes like.  Its at about 1.018 (OG was 1.057).  Taste is as if you mixed a Wit with a Berliner Weisse.  Obviously its very very young, so I'm just checking to make sure there are no off flavors.  All is well!

Barrel Notes: Day 4

It is a much different picture down there than a couple days ago.  The barrel stopped foaming over yesterday, and I've cleaned up the mess.

I didn't expect the small barrel to start fermenting for a week due to the smaller pitch, however, it has already started!  Initially I set it on top a bucket to catch the mess, however, it hasn't threatened to foam over, and considering the shorter fill, I don't expect it.

Even though things look calm from the outside, fear not, there is plenty going on inside.

Wow does it smell good down there!  So far I have smelled pineapple, grape, orange citrus, and that Berliner Weisse lacto bomb.  Not only that, but I haven't picked up any offensive notes.  It's hard to smell the smaller barrel as so much is coming out of the bigger barrel that it over powers the room.  Even when putting my nose close I haven't been able to smell anything unique.  Its far too early to expect to notice any difference due to the different yeast pitched and smaller barrel size, but its something to keep in mind when checking in.

Barrel Notes: Day 2

Upon returning from Central Water's 14th Anniversary party, I walked down to the basement to put bottles in the cellar.  To my surprise I was greeted by this:

Whoa!  I'm not sure when fermentation had started, but this picture was taken less than 48 hours after filling.  Judging by the amount of foam and beer on the floor, it could have been 36 hours or less.  Between my priming efforts and the yeast pitched, I'd say the numbers game is in my favor!

After seeing how much beer I was losing, I recalled reading that Cantillon has started short filling their barrels to reduce the amount of loss during primary fermentation.  Given that my small 5 gallon barrel was lacking about a gallon, I decided to siphon about a half gallon of wort from the large barrel into the small barrel.