Local Lambic - Part
1: The "Bugs"
After reading a blog post by The Mad Fermentationist
that Scott (SNB Brewing) sent to me 2 years ago, I decided to brew a beer and
ferment it using a local wild starter, thus my Local Lambic project was born.
In order to capture my local wild yeast & bacteria
I boiled up some wheat DME with Styrian Golding whole hops - O.G. 1.027 with an
IBU of 23. The half gallon of cooled wort was divided into 3 shallow vessels
and covered with cheese cloth. A sturdy rubber band was affixed to hold the
cheesecloth in place and keep any big bugs and leaves out while the starters
were set out overnight to be inoculated.
One was put in the washing machine near my brewing are
in our garage.
Both side doors were left open so it would be exposed to a draft
breeze all night long.
One was put in the middle of our vegetable garden.
One was put on the other side of our back yard near
several citrus trees.
My plan was to allow each starter to ferment individually
to see what developed from each inoculation location. Any rank foul starters would
be dumped. If any of the little starters goes bad I'll be able to smell and
taste it. Only the good ones make it to the next round where I would increase
the cell count with a larger starter Hopefully, I'd work up enough yeast and
bacteria to ferment a 5-gallon batch of homebrew.
With this approach I wasn’t forced to just roll the
dice and hope spontaneous fermentation happened with the right mix of yeast and
bacteria after investing the time and money to brew a full batch with the hope
that it would ferment into something flavourful.
The wort “Petri” dishes made it through the night OK,
but one earwig made its way into the wort left in the garden. Who knows what
type of “bugs” were on that bug! In the future, I recommend using a double
layer of cheese cloth to keep out the med. size bugs too.
Here's the collection of 3 canning jars with inoculated
starters that were nice and safe after a night of running wild in the back
yard...
In just 2 days, one of the starters was already
starting to show signs of fermentation! Go figure, the one that had the earwig
fall into and it’s the one that got going first!
By the 3rd
day, all 3 of the inoculated “Lambic sisters” were
fermenting away nicely. They all still smelled like fresh wort at that point.
No other distinct aromas, but more importantly, there were no noticeable
off-aromas!!
At that point it was full steam ahead for the project
- Ramming Speed!!
What was collected from my back yard was definitely
some type yeast, but the wort could also contain bacteria like lacto., pedio.,
etc., and probably some brett. I kept my fingers crossed that the earwig didn’t
add any e.coli from the planter soil or any other nasty bugs. Luckily, “bad
bugs” make beer smell and taste bad and the low pH of fermenting wort kills off
e. coli. The blog posting from The Mad Fermentationist that Scott mentioned to
me talks about this stuff in detail and is a real eye opener on how to
logically and safely collect ambient yeast and bacteria for use with homebrew.
I also created sour starter that used raw grain to
create some soured wort that went into the wort once it cooled below 110
degrees. This was done to create add some complexity to the sourness in the
beer and help drive the post-boil pH down. It also ensured I had desirable
bacteria in the mix.
My plan was to conduct primary fermentation in glass
and then age in stainless steel. Both can be easily sanitized afterwards. I
couldn't match the oxygen that permeates through oak, but I planned on opening
up the corny keg and allow fresh oxygen in to help control the brett., pedio.,
lacto. & acetobacter. Other than that it's a bit of a crap shoot - as they
say "Relax, have a homebrew”
I tried to control what I could, and prayed the rest went
down the right road. I’d never done this before, so it’s as much a learning
experience as a chance to manage a fermentation that is much more complex than
any other I've attempted.
After 3 weeks, all 3 starters had a yeast cake at the
bottom, and 2 out of 3 have signs of brett. too. I think the secondary
oxygenating I did increased the amount of brett present - nice white film on
top of the starter.
Because all 3 starters came out so well, I combined
them to inoculate a full gallon and a half starter for the Local Lambic. I
oxygenate the new starter by shaking it quite a bit in order to grow the max.
amount of yeast cells. They'll have to do the bulk of the fermenting of the
wort after all. The rest of the bugs in the mix would do their thing afterwards
with the “scraps” after primary fermentation was finished.
The yeast, etc. grew nicely in the second starters.
Whenever I shook up the bottles, the amount of latent carbonation is amazing!
Houston, I think we are ready to start countdown for
liftoff!
While the aroma of the starters was becoming less
"worty" I had not tasted it yet. The real flavor of a Lambic doesn't
come from the yeast anyway. It smelled fairly clean with a faint lemon aroma.
I'll planned on giving it a taste a week later to see
where it was at, but I needed it to ferment for a while to make sure there's no
chance of e. coli before tasting it. Luckily, the drop in pH caused by yeast
fermentation kills off a lot of really bad bugs. The yeast cake at the bottom
is a bit dark, but it's nearly 1/4" thick now!
I wanted to ensure I had all the hallmark bacteria found
in lambic fermentation, so I supplemented the wild yeast & brett. I’d
captured with bacteria from the grain used in the mash. I made the soured wort as
outlined in a BYO article to add to the cooling wort. I boiled 42g. of wheat DME
in a pint of water for 20 min. When it had cooled to 110 degrees, I added 1/3
cup of slightly crushed Belgian Pilsner malt. The whole mass came to 100
degrees. It would need to sit insulated with a heating pad under it to keep it
between 100 and 120 for the next 3 days. Grain husks have bacteria on it that
will attack and eat the sugars in the starter. I hoped yield a good bit of lactobacillus
& pediococcus which I planned to pitch into the cool-ship once the wort was
about 100 to 110 degrees Fahrenheit. As the wort cools slowly overnight, it
will give the bacteria time to grow before the yeast is pitch.
Here are some photos of how I created the Sour Wort
Starter
Close up of crushed malt
Starter and crushed grain.
Grain in the starter wort
Starter was snug as a bug. I pushed a food thermometer
right through a small hole I make in the lid in order to constantly monitor the
temperature accurately.
Starter resting nicely at 100 degrees
4 days since the soured starter was “brewed” and it
has really taken off!
The Local Lambic starters didn't
show signs of either of these bacteria, but they gave me signs of Yeast and brett. activity. The two starters together should make for a good lambic with some complexity
to the sourness.
In Part 2 (due in Mid May) I’ll
discuss the brew day, fermentation and final flavor profile of my Local Lambic.
How to make your own cool-ship and lessons learned will be included too!