Lacto Starters

Starter wort, for the L. brevis and L.
buchneri to be used in my upcoming beer

Its almost time to brew a quick sour for the upcoming summer...which means that it is time to begin preparing starters of the lacto, sacch and brett going into the beer. Its been a few years since I blogged about brewing this kind of beer - a sour Berliner Weisse which can be ready in as little as 10 days - or which can act as the basis of more complex beers through the addition of Brettanomyces, fruit, herbs and blending with other beers.

But more on that later. Today's post is on a topic I get asked about with some regularity; namely, how to prepare a starter for Lactobacillus. A proper starter is especially important for sour worting, both to minimize the risk of infection by other bacteria, and also to ensure a reasonable souring time (a few days).

The good news is that lacto starters are easy - almost as easy as yeast, but you do need a bit more equipment.

For the starter you will need:

1. 1.040 starter wort (or apple juice, or MRS media)
2. Yeast nutrient (optional, but a good idea, especially if using apple juice)
3. A temperature controller
4. A heat source (I use a crock-pot)

As always, details are below the fold.

Purifying Yeast from Infected Cultures - Part 2

A couple of days ago I put up a post describing the first step in purifying a contaminated yeast culture. In that post I described a simple method (requiring some specialized reagents) which allows a contaminated sample to be depleted of a contaminating bacteria, and also to provide semi-pure cultures of Saccharomyces and Brettanomyces. But as far as that method goes, it doesn't ensure complete depletion of the contaminants, nor pure cultures of Sacc or Brett.

So how do we get a totally pure culture? The answer...streak plating, followed by a quick screen to ensure purity.

Details below the fold.

Purifying Yeast from Infected Cultures - Part 1

Mixed Saccharomyces (large ovoid cells) and Brettanomyces
(elongated cells) yeast culture contaminated with cocci
(top-centre "string") and rod-shaped bacteria

One of the most requested topics I receive is how to clean up an infected yeast sample. I've alluded to the use of streak plates, and basic identification of organisms, etc, for cleaning up yeast previously, but despite that I've yet to give a detailed example of how I go about cleaning up a contaminated yeast sample.

Provenance has smiled down on me, in the form of an infected attempted bottle culture of a mixed sacch and brett fermented saison from The Bruery, provided to me by a local home brewer. The contamination was not a "good" one - i.e. not a lactic acid bacteria contamination - but rather one that produced a rather putrid sulphur/brimstone aroma.

So how do we fix that...and how can we easily get pure strains of the brett and sacc strains used in the beer?

In this, the first part of a 2-part post (part 2 can be found here), I will go through a basic procedure to enrich the Saccharomyces and Brettanomyces from the infected culture using a selective/differential media and culture conditions to enable the growth of the desired yeast species while inhibiting the growth of the undesired bacteria and yeast. In part 2, hopefully posted later this week, I'll go through a final clean-up procedure to ensure the resulting cultures are, in fact, clean of the contaminating yeast and bacteria.

As always, details are below the fold...

May the Fourth Be With You

Image From Shirtigo, no affiliation

Return of the Black Mamba

The hops for this beer.

I was digging through the deep-freeze a few weeks ago and came across the tightly vacuum wrapped remains of 2014's hop harvest - 270 g (~9.5 oz) of Cascade hops. Not to sure what to with my unexpected bounty, I looked back to see what I did with the home-grown Cascades last year. Turns out last years beer was an Black Imperial Rye IPA - The Black Mamba IPA. Tasting notes (and memory) revealed that this was one of last years better beer, so I thought "what the hell, lets do it again".

Last years beer ended up being under-gravity (more a BRIPA than a BIRIPA) as I  had begun experimenting with wet milling my grain and had over-whetted the grain. I've now optimized this method, so I hope to hit the desired gravity (1.071) instead of missing it like I did last year (1.059).

But what to do with all those hops? The answer - add them all to one beer! For accuracy, the 75 minute bittering addition will be 34 IBU's of Northern Brewer, but everything else is the home-grown cascade.

My (hopefully temporary) $10
3-tier mash system

How do you work in 270 g (over a half-pound) of home-grown hops? The answer is lots of additions - 57 g (~2 oz) at 20, 12 and 5 minutes, plus another 57 g in a 15 minute hop stand (half added at flame-out; half added 7.5 minutes after flame-out). But that leaves 34 g (~1.5 oz) unaccounted for - that would be the prime hops; the ones I put aside into their own little pack as they had the most resin and aroma of the harvest. Those are being held back for a 3-day dry-hop after primary fermentation is complete. Estimated IBU's are 67; maybe lower or higher depending on just how bitter the home-grown hops are.

Grain bill is pretty much unchanged from last year - good quality Canadian pale malt as a base malt, 25% rye for that refreshing rye crispness, some carafa special II & victory malt to round things out. Again, I am trying Conan, but will coax more ester flavour out of it by under-pitching (50% the recommended rate) and minimally oxygenating the wort. Fermentation will begin at 18 C (65 F, AKA my basements temperature) and ramp up to 22C (72 F) to finish. I'm going all-out, and even altering the water to up the sulphate and magnesium to make the hops pop.

Full Recipe & Brewday Notes Below The Fold

100,000 Views!

When I started this blog a few years ago I didn't expect it to amount to much - this was intended as more of an unlosable brew-log (which it has failed as; I'm horrible at recording my brewdays here), but has morphed into something completely different. As of right now I'm a few hits away from 100,000 views (not counting my own), and will probably cross that mark by the time I hit the "Publish" button.

I'd like to thank all my readers for your interest in what I've been writing here - the ongoing hits, comments emails - and more recently youtube views - are what motivate me to add new material.

So to all my readers/viewers, thank you. I'd also like to thank my major traffic sources (check them out - they're all great):

• Canadian Homebrewers
• Homebrew Talk
• Bootleg Biology Blog
• Milk the Funk Facebook Group (private group)
• Jeffrey Crane's Blog

BREAKING NEWS - White Labs Official Statement on Brett trois.

As the followers of my blog are likely aware, there has been a growing body of evidence that WLP644 (Brettanomyces trois) is, in all likelihood, a Saccharomyces (conventional brewing) species. I, and other bloggers did a series of genetic tests that pretty firmly nailed down the genus  of WLP644 as Saccharomyces (although the exact species remains somewhat nebulous).

Many brewers have been directing questions at White Labs about this, and their reply to-date has been rather guarded. Today, they broke their silence (PDF), and confirmed that trois is, indeed, a Saccharomyces. Ironically, they've based this on a far less robust measure than the data myself and others have generated - they determined the genus simply by looking at the size of one of the regions myself, and others, sequenced to ID this yeast.

White Labs has an extensive sequencing project on-going which I expect will reveal to us some exciting (and perhaps upsetting) data on the yeast strains we know and love. While WLP644 is clearly a Saccharomyces, the exact species remains unclear - indeed, one of the sequences we have floating around suggests it may be something all together new. Indeed, white labs is rather guarded in their conclusions (they call WLP644 a "brux-like Trois"), which makes me suspect they too didn't get a clean species ID on the yeast.

More updates to come as more information becomes available.

Previous Posts:

• Brett Trois - A riddle, wrapped in a mystery, inside an enigma
• A (sort-of) update on Brett trois