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 3^rd 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!

Oxygen Flow Meter for a disposable oxygen tank

Years ago Liquid Bread came out with what was probably the first oxygenation setup for homebrewers that included a tank of Oxygen (Bernzomatic), a regulator, hose and a 0.5 micron stone. I still have all of the reusable parts to that kit over a dozen years later.

While I’ve read how much oxygen ppm a brewer should try to achieve, it was impossible to calculate if my method was helping me achieve my goals. I’d open up the valve until I was at a flow rate where the bubbles were gently breaking the surface of the wort, but it was always a guess if that was the right way to do it.

While reading Yeast by Dr. Chris White and Jamil Zainasheff I came upon some solid info. on how to achieve various levels of oxygenation so long as I could ensure my flow rate was 1 liter per minute (lpm).

Unfortunately, the regulator from Liquid Bread is rudimentary and couldn't be modified to attach a quality flow meter. I did not want to use a cheap inline flow meter which would require me to grow an extra set of hands to keep it hanging vertically, so I decided to build my own setup from scratch.

The parts:

• Pediatric Flow Meter
• Regulator for a Disposable Oxygen Tank for jewelers
• DISS 1240 to 1/8” npt Adaptor
• 1/8 npt female to male Adaptor
• Plastic Toilet Flange
• Gas Line Teflon tape

The flow meter scale – 1 lpm was my target….easy to read on this scale! When the oxygen is flowing, the ball hovers and reading the flow rate is extremely simple. The middle of the ball is where I take my reading.

The old "dumb" regulator and the killer new one I built. 

This is the special DISS to npt adaptor from Bay Corp. with the butt end of the flow meter to the left and the standard barb attached on the right.

This is the 1/8” npt female to 1/8” npt male adaptor joining the flow meter to the regulator. The regulator out flow has a male reverse flare fitting.

Unfortunately, I could not locate a female reverse flare to 1/8” npt male adaptor, but the adaptor I used tested negative for leaks. Use the right adaptor instead if you can find one.

The entire setup with the new toilet flange base stabilizes the oxygen tank

and makes operation hassle free.

Where to get the parts and where to use in the build: 

• From a seller on eBay I bought a Pediatric Flow Meter for $22.00. I highly recommend using a pediatric flow meters because the scale is from 0 to 3 lpm, so measuring my goal flow rate of 1 lpm is easy. The standard flow rate meters I saw for sale have a scale that does from 0 to 8 lpm, so the pediatric meter is much easier to read.
• From a seller on Amazon I bought a Regulator for a Disposable Oxygen Tank normally used in the jewelry business for $33.00. It comes with a threaded connector, so I would be able to attach the flow meter.
• Bay Corporation makes a DISS 1240 female to 1/8” npt female adaptor (P/N  1242-8). This is needed for the outflow side of the flow meter so I could then attach a 1/8” npt male to 1/8” barb connector. This special adaptor is hard to find. It’s only available from many medical supply companies. I bought mine for $8.92 from Medsurge.com
• I also bought a 1/8” npt female to 1/8” npt male adaptor to attach the flow meter to the tank regulator. The threads on the regulator are actually 1/8” male reverse flare type. This is nearly identical to npt. The tpi is the same, but the taper is different between the two types of pipe. The reverse flare has nearly no taper at all, so I had to use 2 wraps of gas line Teflon tape and screw the adapter all the way on and give it a good crank to ensure it was down to the narrowest part of the adaptor and was properly sealed. I successfully tested and passed the seal between the fittings using a soapy water test like you would use to find a leak in a bicycle inner tube. Please use the correct female reverse flare to male npt adaptor if one is available so you can be confident your oxygen isn’t leaking out during use.
• In the end, this setup gives me two valves where I’d prefer to have one. Once the tank regulator is opened up, it’s easy to set the flow rate using the valve in the flow meter.
• Having the flow meter stick out caused the tall, skinny oxygen tank to be unstable and it wanted to fall over pretty easily. Luckily, a Plastic Toilet Flange from Lowe’s has an ID of 3” which is a perfect fit for the disposable oxygen tank which is 2.9” diameter. Cost was just under $5.
• I used Gas Line Teflon tape for all fittings. Oxygen is far too flammable to mess around with, so I played it safe.

Total cost for this custom made flow meter for disposable tanks was just over $70. That’s about triple what a “dumb” tank regulator from a homebrew shop costs ($19.99 at Williams Brewing), but without knowing the flow rate it’s is very hard to consistent when oxygenating your wort for those big beers that need more than 8 ppm.