Sunday, July 19, 2015

Lactobacillus Plantarum Gose: Sourcing Lacto from Probiotics



There is seemingly a never ending parade of new strains of Saccharomyces, and the last few years Brettanomyces, being released on a consistent basis to both the professional and home brewing world. But the diversity of Lactobacillus species on the market has been sparse to say the least. As sour wort\kettle souring with pure culture strains of Lactobacillus has become even more popular, folks (myself) have been looking for some different cultures other than Delbrueckii and Buchneri which White Labs and Wyeast have carried for years. Especially with the White Labs L. Delbrueckii culture having a reputation of being cross contaminated with cells of Saccharomyces resulting in very little lactic acid in finished beers. 

Labs like Omega and Gigayeast have stepped to the fore with some great blends of various Lactobacillus Species but after reading Matt Humbard's comprehensive research on Lactobacillus I was really interested to try some them on their lonesome. The species that stood out the most to me from Matt's article was Lactobacillus Plantarum. It has a few redeeming qualities that I have been searching for, its Homofermentative, acidifies very quickly and does not seem to need a ton of heat to achieve that acidity. Make sure you read through his article as I couldn't do half as good a job as describing L. Plantarum, among other species, as he can. 


I couldn't locate any labs that sold a pure culture Homebrew sized pitch of L. Plantarum, although there may be for pro brewers. After chatting with some folks on Milk the Funk  I came across these Probiotics from Swanson.  Each capsule is reported to have 10 billion cells of dry L. Plantarum and at that price its hard to beat, so I figured they were worth the try.

Reading post fermentation.

Using the same short brewday sour wort method, and recipe as in the previous post, I brewed up another Gose for further summer enjoyment. I cracked open 3 of the capsules of the Swansons L. Plantarum and got them into 750ml of starter wort, left unstirred and held at 105F for 36 hours. The starter reached a pH of 3.3 in that time, then the whole starter was pitched into 100F wort in a Better Bottle. I held the sour wort at only 95F, since I read Plantarum can acidify a little cooler than other species. After 48 hours of sour worting the pH was 3.31 and it was very tart, I made the mistake of not taking a gravity reading here but have on more recent batches and the gravity drop has been minimal. I pitched some US-05 and fermentation was done about 48 hours later (4 days total) at 1.003 and 3.31pH, the beer was kegged on the 12th day of fermentation. 


This batch was 5 IBUs and L. Plantarum had no problem at all acidifying the beer quickly. In recent batches I have used 8 IBUs and 10IBUs (calculated) reaching pH levels of 3.35 and 3.40 respectively. I plan to test it out at some high IBU concentrations but it's looking like a fairly IBU tolerant strain that suits my boiled, hopped, sour worted method. I will update later on in the summer after I play with some high IBU worts and how L. Plantarum worked. Below are tasting notes for this batch, recipe after the notes.


Nobody Gose there anymore, it's too crowded: with Probiotics.

But do you Milk the Funk?

Appearance: The beer is almost white in color, the photo doesn't do the color justice, extremely pale and hazy. Soapy bright white head, it fades but not as fast as you might think, and there is a decent ring of head that hangs on top the entire glass. Usually head retention in these beers are awful due to the low pH, not in this beer and not in any of my sour worting beers. Not sure why that is, I guess I'm doing something right.

Aroma: Raw malt aromas, like sticking your face in a bag of Pilsner. Slightly bready, a bit rustic, lemony and and noticeably acidic. A bit of funk and spice from the coriander, some Belgian-esque esters that I wasn't expecting.

Taste: Acid upfront as expected, prickly as it crosses the tongue due to the acidity and some carbonic acid but this isn't a highly carbonated beer. Cleanly lactic, subtle Belgian-esque spice following the nose, maybe that's the coriander though. The salinity is very low, and finish is dry and acidic with a slight pucker in the back corners of my mouth. 

Overall: Very refreshing summer crusher, as compared to the last batch it's more sour and light on the salt and coriander character but I dig it. It has a really nice grainy character, like uncrushed raw malt, it's dry and perfect acidity wise, for what I want not as a classic example.  The ease of these L. plantarum tabs make this a real winner for me. I'm wondering it the Lacto added the raw character to the beer, maybe the esters as well. 

I most certainly use these tabs again, I may use them blended with other species of Lacto like Omega does with their blend but just to see how things differ. Its a great cheap source of aggressive Lacto that's readily available to anyone.  



Brew day: 5/25/2015
Multiple fermentations in the dark.
Kegged: 6/6/2015

Recipe Specifications
--------------------------
Boil Size: 6.00 gal
Post Boil Volume: 5.80 gal
Batch Size (fermenter): 5.50 gal
Bottling Volume: 5.00 gal
Estimated OG: 1.035 SG
Measured OG: 1.036 SG
Measured FG: 1.003 SG
Beer pH: 3.31
ABV: 4.2%
Estimated Color: 3.0 SRM
Estimated IBU: 5 IBUs
Brewhouse Efficiency: 70.00 %
Boil Time: 2 Minutes

Grain:
50.0% - 3lbs 11oz - Weyermann Pilsen (1.5 SRM)
50.0% - 3lbs 11oz - CMC White Wheat (3.5 SRM)

Hops:
Boil: 2mins - 0.75oz  Strisslespalt [3.9 %] 4 IBU
Boil: 2mins -  0.50oz Sea Salt
Boil: 2mins -  0.50oz Coriander, freshly ground seeds.


Mash:
Sacch rest - 60 min @ 148 F 

Sparge:

No Sparge, full volume of water in the mash, 7.10 gallons.

Misc: 
5ml lactic acid in the mash, Mash ph 5.35.

Wednesday, July 1, 2015

The summer of Gose.

I would normally use a swing top 1L growler,
to keep the o2 at bay, but it wasn't available.
There may not be a more popular trend in American craft beer right now than the revival of German Gose. Over the last few years the beer community has been focusing more and more on session strength beers and with sours rapidly growing in popularity Gose fits both trends. Gose (pronounced Goes-Ahh) shares some similarities with Berliner Weisse they are both low in alcohol and tart, but Gose is brewed with a saline water profile giving the style a very unique personality. Like Berliner Weisse, Gose is brewed with a 50:50 mix of wheat and barley, spiced with coriander and a small amount of hops in the boil then finally fermented with a blend of lactic acid and Saccharomyces. What you end up with is a slightly salty, light bodied, floral and tart beer in the 3.9%-4.9% ABV range. I don't consider myself an expert on the history of Gose but it has been a dying style over the years, making it very difficult to find classic examples. If you're looking for more background or history check out This articleThis one, or the ever growing Milk The Funk Gose Wiki for more links and information (watch that video, its great).


A few years ago I played with a technique called Sour Worting to brew some tart Berliner Weisse beers (mostly no boil versions, a bit too inconsistent for me), which from the production level, as I mentioned, is quite similar to Gose. The idea behind Sour Worting is to give Lactobacillus Bacteria a head start on creating lactic acid, a key component of the style, under conditions that favor the bacteria. The brewday using this method is quite short, about 2.5-3 hours for a 5 gallon batch in my case and with my second child on the way this fall I see a lot more of these in my future.
co2 purging the Better bottle.

I start by building a 1L starter for the Lactobacillus strain I am using, in this case L. Brevis from White Labs, incubated warm at ~100-120F in an anaerobic environment for 2-3 days. After which I take a PH reading to ensure things are progressing, so long as it's under 3.8pH I assume we are in good shape. I didn't follow these procedures on this batch but check out the Starter Media for Lactobacillus post on Eureka Brewing. I plan to implement his results going forward when build the media for a Lacto starter.

Brewday for this beer is pretty standard until we hit a boil, using a no sparge setup I mash with all my water for 60 minutes then run off to the boil kettle and hit a boil. Once the boil is achieved I add a small amount of hops, 1/2oz of Sea Salt (go light on the salt to start, you can always add more at packaging but can't take any out!) and Coriander. Let the boil roll for a couple minutes, just enough to sterilize the wort, and then cut the heat. Keep in mind that the hopping rate when working with Lactobacillus is key. High IBU concentrations can inhibit certain strains of Lactobacillus' growth and thus their ability to create lactic acid. Keeping the IBU's under 5, or even none at all, is a good guideline to follow. Any more than 5 IBUs and your chosen Lacto cultures may have a difficult time dropping the pH to the levels you desire. 

After the short boil the wort is chilled to 120F its gently transferred to a co2 purged fermentation vessel so as not to aerate the wort, as most strains of Lactobacillus perform optimally in an anaerobic environment (strain dependent, and I've read this may not be the case with Brevis).  At which point I pitch the starter of my Lacto culture, and use a heating pad to incubate at ~100F for 2-5 days, or once desired acidity (or pH) is reached. Pre-acidifying the wort with 88% Lactic Acid prior down to 4.5pH, to pitching your Lacto starter, sets you up with a more optimal environment for Lactobacillus to perform (among other reasons regarding head retention). 
Be warm my babies.

After 48 hours of incubation I pull the first sample to check gravity, pH and give it a taste. If you have an active Lactobacillus culture built up there should already be a big drop in pH and a noticeable acidity, with residual sugars remaining the acidity can be overshadowed so make sure to measure either pH or Titratable Acidity. This example was a little slow, the pH was 3.9, down from 4.5 my vial of Brevis was about 3-4 months old so that could have been the culprit. One thing I would like to mention here is that White Labs states their Brevis (a heterofermentative strain) culture can achieve 80% AA which is fine so long as it creates the acidity I want and ferments out clean. I've been experiencing full attenuation in 3 days using their culture which cuts into the creation of Lactic acid for an otherwise Lactic acid driven beer. This has prompted me to play with other strains and blends of Lactobacillus, mostly of the Homofermentative variety, for the most optimal fermentation, posts on those to follow.

In most cases I would reach my target acidity or pH, chill the fermentor down and add a strain of Saccharomyces or Brettanomyces to ferment out the rest of the beer, most folks find US-05 works well in those low pH environments. But in this case Brevis achieved 85% AA and the beer was cleanly fermented and had a decent acidity finishing at 3.65pH (I wanted a bit more though it tastes great) so there was no need to add a secondary strain. If the beer does not finish as acidic as you would like you can choose to dose the beer with some 88% Lactic acid but use a deft touch as too much can be overwhelming. Some people think it tastes synthetic, or medicinal, in high concentrations but if used lightly it can get the beer closer to where you want it.

This batch was brewed, fermented out, kegged and tapped in 14 days at a pH of 3.65. Below are tasting notes after being on tap for about 3 weeks, with the recipe details below.

Nobody Gose There Anymore, It's Too Crowded

Appearance: Hazy very pale yellow color, almost white-ish, with a wispy bright white head that fades quickly due to the acidity. Moderately high carbonation (carbed to 2.5vol). Always an odd color with these short\no boil beers.

Aroma: First wafts are pretty clean, with a bit of a grainy\earthy character and a touch of spice and lemon zest. The aroma is not huge, but you can tell it's going to be a lactic beer.
Fresh pour, haze abounds, head fades.

Taste: It starts with a slight tartness upfront immediately followed by a bit of salinity. The the wheat character takes over in the middle of the mouth lending more body than you would expect, finally finishing lightly tart with a sting on the sides of cheeks fading and finishing very dry. 

Overall: Its a very delicate tart beer with notes of lemon, grain, and a moderate salinity. The finish is dry and tart, it makes your teeth dry as you clammer for another sip a similar sensation to when drinking a fresh squeezed lemonade. At the 4% ABV range I have been crushing these after mowing the lawn mid-day on a weekend, I'm a suburban Dad now no long a city Yuppie, which makes this is acceptable practice. When I kegged the beer I was underwhelmed as I thought it needed more acidity, I still think that, but it ended up being a very balanced beer that reminds me more of the very few classic German Gose I've had. Although I was reaching for something like Westbrook Gose on the acidity scale I am very pleased with how this came out.


Brew day: 4/28/2015
Kegged: 5/12/2015

Recipe Specifications
--------------------------
Calibrating and measuring pH.
Boil Size: 6.00 gal
Post Boil Volume: 5.80 gal
Batch Size (fermenter): 5.50 gal
Bottling Volume: 5.00 gal
Estimated OG: 1.035 SG
Measured OG: 1.038 SG
Measured FG: 1.006 SG
ABV: 4.2%
Estimated Color: 3.0 SRM
Estimated IBU: 5 IBUs
Brewhouse Efficiency: 70.10 %
Boil Time: 2 Minutes

Grain:
50.0% - 3lbs 11oz - Weyermann Pilsen (1.5 SRM)
50.0% - 3lbs 11oz - CMC White Wheat (3.5 SRM)

Hops:
Boil: 2mins - 0.75oz  Strisslespalt [3.9 %] 4 IBU
Boil: 2mins -  0.50oz Sea Salt
Boil: 2mins -  0.50oz Coriander, freshly ground seeds.


Mash:
Sacch rest - 60 min @ 148 F 

Sparge:
No Sparge, full volume of water in the mash, 7.10 gallons.

Misc: