Saturday, 24 September 2016

One brew day - several sour(ish) beers

Random "helper" captured while preparing the fruit for this beer
This is a big post, providing information on three very different beers, all brewed from a single wort a little over a month ago. This has been (and continues to be) a pretty exciting series of beers - from a single wort I made a dry hopped berliner weiss, an experimental beer with the yeast Lachancea thermotolerans, and a fruited/bretted beer using wild grapes and the flora of those grapes!


At the heart of these three very different beers is an incredibly simple wort - a 44L (11.6 US gallon) batch of a no-boil Beliner Weisse, based loosely on the Milk the Funk Berliner Weisse recipe. Rather than post my recipe, I'd direct you to the previous link. The only modifications I made were in my procedures:

  1. I mashed at 62.8C for 75 minutes, to get a drier final beer than the MTF standard recipe.
  2. The wort was not boiled; instead I heated it to ~90C, and let it sit at this temperature for 10 minutes prior to cooling to 45C for pitching of the Lactobacillus.
  3. No hops were used in the mash or boil.
Once the wort was prepared 4L was pulled off for the experimental Lachancea thermotolerans beer, the remaining 40L kettle-soured with a fantastic wild lactobacillus available only to my home brewing club, and once soured, split into two batches - one dry-hopped upon completion and the other bretted and fruited with wild grapes.

The details of each of these beers, and tasting notes for two of them, can be found below the fold. Its a bit of a read, so you may want to pull yourself a pint before you proceed.

Lachancea thermotolerans

L. thermotolerans beer
This was supposed to be a side-by-side of two different Lachancea species - L. thermotolerans and L. fermentii. Unfortunately, while the "thermotolerans" is reflective of that species better high-temperature survival, it is a relative term, meaning that the L. thermotolerans barely survived the 28C incubator I use to grow my yeast, while the L. fermenti died screeming. So this experiment got paired down to a single species of Lachancea.

My interest in these yeasts is motivated by a fairly unusual characteristic of them - namely, that they produce lactic acid. In theory, these yeasts could be used to prepare a Berliner Weisse or Gose style beer without the use bacteria for souring. This could be a great time-saver, and remove the concerns raised when introducing souring organisms into a brewery.

The 4L of wort used for this beer was transferred into a 4L glass fermenter and a small (250 ml) starter of L. thermotolerans pitched. Within a few days fermentation was complete, but I let it sit an additional 2 weeks to give the yeast a chance to clean up any off-flavours. The beer was then transferred to 500 mL plastic bottles and force-carbonated with a carb-cap.

Sadly, this yeast did not make a nice beer. The beer itself looks nice, much clearer than expected given the wheat content of the beer and lack of hot-break. But as pretty as it is, the flavour simply does not work. This yeast has a very strong ester character, similar to apple cider (not the green-apple taste of acetaldehyde, but rather the taste of unfermented apple cider). This is "complemented" by a sweetness (from the esters I assume, given the FG was 1.002) along with a bit of an "unclean" flavour that is hard to describe. The level of acidity is very modest - a mild "tang" along with a bit of a lactic taste. In my opinion the lactic character clashes poorly with the apple character...my wife, who hates beer, disagrees and actually likes this beer quite a bit. I'm aging some of this beer for an additional few months to see if it improves; I'll post on this sometime in October.

Dry-Hopped Berliner Weisse

After pasturization and pulling the 4L of wort for the Lachancea thermotolerans beer, I cooled the remaining 40L of wort to 45C, at which point I pitched an ~1L starter of my brewing guilds custom lacto strain, named "Lacto godzillicus" after its ability to sour almost anything at almost any temperature. I insulated my kettle with a bit of water-heater insulation (see my old post for how I set this up) and let the temperature free-fall to ambient (about 25C in my garage) over a period of 2 days. At this point the wort was fully soured, and I transferred it, unpasturized and without additional boiling, into two 23L carboys.
40L of soured wort, 12 hours after pitching yeast
Each carboy was pitched with 1 packet of rehydrated US-05, which as it turns out, was a poor choice of yeast (unlike my preferred Wyeast 1007, US-05 is quite slow in soured wort and took 2 weeks to ferment to completion). Rather than affixing a blow-off tube, I simply put a foil cap on top of each carboy, which was replaced after the main fermentation completed (~6 days) with airlocks. 14 days after pitching the yeast I dry-hopped one of the carboys with 60g (~2.4oz) of Galaxy and 30g (~1.2oz) of Citra. Three days later I transfered the beer to a carboy and force-carbonated to 2.4 volumes.

Unlike the first beer created from this wort, this one did not disappoint. In fact, it may be one of the best beers of 2016! Here's the breakdown:

Appearance: Pours straw-yellow, with a faint wheat haze. The head on the beer is thick and pillowy. Sour beers often have a reputation for poor head retention - I don't know if its because of the no-boil approach, or the particular lactobacillus used - but the head on this beer lasts and lasts and lasts, leaving Belgian lace on the glass right to the last sip.

Aroma: A refreshing papaya and citrus note dominates the aroma of the beer. A subtle lactic character is also present in the background.

Flavour: WOW. Up front is the acidity provided by the lactobacillus - its not an intense, enamel-stripping acidity, but rather is a more modest acidity. This sourness perfectly balances the tropical fruit flavours provided by the hops, which provide not only a fruit flavour, but also a subtle sweetness. The combination of the two provides a character almost that of fruit juice - though-be-it, a quite acidic fruit juice. The malt provides a soft bready character to the beer - but while present, this character is subtle and comes out more in the aftertaste than in the sip of beer itself. The aftertaste is a mix of fruit-sweetness and bready maltiness, which fades into a nice fruit note.

Mouthfeel: The beer is dry and provides an acidic tingle on the tongue. Very, very refreshing.

Overall: Hot damn, this is a good beer. Well balanced, refreshing, easily drinkable and yet also a beer which you can slowly savour. A great beer to enjoy in the dog days of summer. One of the better beers of this year, and quite possibly the best Berliner I've brewed to date.


Fruited Berliner

This final beer originated as more an accident than anything else. The second carboy of Berliner I described above was transferred to a secondary carboy the same day I kegged the hopped Berliner Weisse, and had been sitting in my basement, giving off a distinct desultory vibe, ever since. I knew I wanted to add some Brettanomyces character to it, and I knew I wanted to add fruit, but couldn't think of a combination that excited me. I had an epiphany on my cycling ride home from work one day - along my route is a rail right-of-way, and all along it wild grapes grow throughout the trees which are fruit-laden in late August and early September. Usually these things are an irritation - the grape vines have a tendency to snag unwary riders, and the birds turn the pathway into a purple-shit coated slipway. But the stars aligned, the muses sang (or some such thing happened), and I realized they may be a perfect (and free) addition to my beer. That night SWIMBO, the offspring and I headed out to the pathway, buckets in hand, and picked over 8kg (~18lbs) of grapes. The next day we destemmed the grapes, washed them in cold water, spread them out on cookie sheets and froze them in the deep-freeze.
Left: ~10 minutes after adding grapes, right: 3 weeks after adding grapes

Once frozen I measured out 2.5kg (5.5lbs) of the grapes and dumped them into the carboy, along with a 300 ml starter of Brettanomyces clausenii. I chose this strain of brett as I expect the grapes to have a strong tannic character, and thus wanted a fruit-forward strain, rather then phenol-forward strain, to better complement the tannins of the grapes. Almost immediately after adding the grapes the beer turned a dark blue colour, which over the next few weeks deepened to a dark purple. This beer continues to ferment and age, with a planned kegging date of mid-November. So for now I can leave you with only a picture of the beer, and a promise to blog about it further once it is done.

3 comments:

  1. Hi, great article, I was just wondering why did you decided not to boil wort? Is there an advantage?

    Thanks
    Enda

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    Replies
    1. Normally I boil my belriners twice - after the mash, and after souring. I avoided both boils this time for differing reasons. Avoiding boils (in general), for Berliners, has a reputation for better preserving the malt character, giving a 'breadier' finish. I had not done a no-boil previously, so I wanted to see whether I could pick that up in my berliners. I'm not sure I sense much of a difference, but I'm also not comparing side-by-side.

      I didn't pasteuriser/boil after souring as I wanted the lacto to carry over into the fermenter.

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  2. Great Bryan thanks for getting back to me. It would be interesting to do a side by side to see if there is any difference, especially on the perceived malt character. In darker beers with more specialty malt it might be even more apparent.

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