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.

Friday, 16 September 2016

It's Back

A few of my past exchanges.
As many of my long-term readership knows I used to offer access to my extensive yeast bank on an exchange basis. Due to a mix of personal and professional reasons I lacked the time over the past year to engage in yeast exchanges, and took the bank off of the interwebs.

The drought is over.

Both my commercial and wild banks are back open for exchange (with some exceptions, where I've promised to not exchange certain yeasts). As in the past, all exchanges are trades - you give me something new and I'll send several your way.

The link to the exchange can be found at the top of the page, or by clicking here.

I use a system of mailers which makes exchanges cheap and easy. Details can be found on the exchange page, or at this link.


Tuesday, 30 August 2016

A Great Review on Sour Beer Bugs

Mat "Dr. Lambic" Miller, author of the Sour Beer Blog, just posted one of the best and most comprehensive reviews of brewing organisms used in sour beer production, as well as the myriad of ways that they can be applied to the production of sour &/or funky beers.

Whether new to the sour scene, or an old hand, its a post worth reading.

Thursday, 25 August 2016

Imperial Pale Lager...with Frozen Yeast

A few weeks ago I posted a video about freezing yeast. While many people were quite excited about that video, I did have a few doubters. Well, I'm going to let you into a little secret - I shot that video back in March (yes, that is how slow I am at editing videos), the yeast I froze down in the video was a product of February's "Uncle Mikes Pilsner". One jar of yeast saved from that batch was re-pitched (without a starter) to make Aprils Vienna lager, another jar (this time with a starter) made the Helles and Raddler brewed in May. And at the end of July I thawed one of the frozen tubes of 34-70, ran it through a starter, and made an IPL...and it is f~#&ing delicious!

The recipe is below the fold, but lets start with the tasting notes.

Appearance: The picture to the right says it all - dark copper in colour, crystal clear, and pours with a creamy white head that leave Belgium lace down the sides of the glass.

Aroma: Citrus, citrus and citrus. Not a surprise given the recipe (again, below the fold), but regardless, the aroma is fantastic. The mild lager character of the yeast really lets the hop character shine through.

Flavour: I like my IPA's/IPL's on the bitter side, and this recipe doesn't disappoint. The beer has an upfront bitterness, clean but lingering. Behind it is a nice maltiness; pilsner-malt graininess with a bit more oopmh provided by Munich malt. Beside it there is a strong hop flavour - citrus, some resin, bit of tropical fruit. After the sip is complete all of that fades quickly to a resinous hop bitterness with a touch of sweetness to balance it out.

Mouthfeel: Dry, effervescent, but still somewhat whetting. The wetness fades to a dry hop bitterness as the mouthfeel fades.

Overall: A very enjoyable beer. I would up the whirlpool by another 30g (1 oz) or so to bring a little more hop character to the forefront. Other than that, I wouldn't change a thing. As with many IPA's/IPL's, the hop character fades quickly with time, so rapid consumption is a must.

Thursday, 11 August 2016

Fact or Fiction? Can Pathogens Survive in Beer - Mould Edition.

The topic of pathogens in beer is a persistent one; two years ago I wrote an extensive post on the topic (the answer is, yes, pathogens can survive in beer, but is a thankfully rare issue). More recently a similar theme consistently comes up in the various brewing forums I participate in. The new theme regards moulds (molds, for my US readers). There is no question that mould can grow on beer - indeed, most of us have seen them at one time or another. Rather, the question is if they are dangerous and whether they can be prevented.


What Exactly Is Mould?

Contrary to what many people believe, moulds are not bacteria - evolutionary speaking they are far closer to us than to bacteria. Rather, moulds are the close cousins of yeast, both of which are fungi. Yeast and moulds are very similar in their genetics, cell structure, and even some aspects of their lifestyles. There are two major features which separate yeast from moulds. The first is that moulds are almost exclusively obligate aerobes - meaning they only grow in the presence of oxygen. Some yeast are also obligate aerobes, but the yeast we use in brewing are capable of some degree of anaerobic metabolism - AKA fermentation - and thankfully so, or there'd be no alcohol in our beer. 

The second difference is how mould versus yeast cells assemble. Yeast cells are individually living cells, meaning that each cell is its own fortress and takes care of itself and no one else. Even when yeast form into filaments, they are merely "glued" together. Moulds are the opposite - moulds always form filaments, with each cell in the filament connected to its neighbouring cells such that they can share nutrients, energy, and waste.


Are Moulds Dangerous?

The answer here is "often, but not always". Moulds were (and in undeveloped areas of the world, remain) a serious issue in food safety. Even in the brewing world, moulds were an issue upto the 1930's, and its only because of our food safety measures that they've remained a historical issue. Historically, the primary fungal issue brewers faced was ergot, a fungal infection of barley (and other cereal grains) which can cause an oft-fatal disease called ergotism. This toxicity is caused by the production of an LSD-like molecule by the fungus, which when ingested could cause issues ranging from mild digestive discomfort, through to convulsions, gangrene, and far too often, death. Today this is largely a non-issue as improved grain production and harvest methods have eliminated ergot from the food chain, outside of a few small scale producers and the developing world. Ergotism was a frequent complaint (and/or preferred feature) of many beers in early European history. It was a common problem in the Anglo-Saxon era, and may even have been a "feature" of shamanic beers produced by the vikings.

Another serious historical issue, although it was not appreciated at the time, was other, more insidious mould infections. Many moulds (as well as some yeasts) produce toxins - biological products with poisonous effects. Mould-derived toxins (mycotoxins) are very different from those made by bacteria; most bacterial toxins are proteins and are readily destroyed by factors such  as the boiling, acidity and alcohol present in beer production. Mycotoxins are very different - most are small stable organic chemicals which are impervious to conditions encountered in beer production. Some of these toxins even have cumulative effects, meaning that multiple exposures to levels with no immediate toxic effects could ultimately be deadly. This often manifested itself as cancer - indeed, until the widespread use of refrigeration, stomach cancer was the most common cancer in the western world - a cancer caused almost solely by fungal toxins in improperly stored foods. A combination of refrigeration and antifungal pesticides has purged this scourge from our food supply, albeit, not soon enough to save my grandfather who fought (and ultimately lost) a 15-year battle with stomach cancer that was almost certainty caused by fungal toxins.

In terms of the toxins themselves, how long they take to form and how toxic they are is extremely variable. Gliotoxin, produced by Aspergillis (as well as other fungi and even some yeast) is produced almost immediately upon initiation of cell division. Other toxins may even be present in the spores, while yet others won't be produced until significant amounts of fungi are present. Aflatoxins,one of the most common types of fungal toxins, and commonplace in many grain (and home) loving fungi, is the predominant toxin responsible for stomach cancer. Other long-term effects of mycotoxin exposure can include immunosuppression, liver and kidney damage and reproductive issues.

So fungal toxins are dangerous - but how common are they? The answer there is complex; of all fungi, those which produce mycotoxins that harm humans are relatively rare. However, the toxins are common in the fungi which tend to thrive in our foods and in our homes. If you see a mould in your home, chances are better than 50-50 that it makes a toxin which can harm you. As a general "rule", pigmented fungi are more likely to produce toxins than are unpigmented (white) fungi, but that is not a universal rule. Indeed, the mould used to make blue cheese is intensely pigmented and yet is harmless to us (unless you are allergic to penicillin), whereas nonpigmented fungi are responsible for 2/3rds of fungal eye infections.


I Have Mould In My Beer - What Should I Do?

What should be done if there is mould on your beer is not an easy question to answer. Mould is not uncommon when brewing fruit beers; fruits often carry mould spores, and since fruit tends to float, it carries to mould to the top of the beer where it is exposed to oxygen and can grow. A small amount of growth under this situation is probably harmless, and can be easily managed (see section below). Mould on a non-fruit beer is more problematic, as it indicates that the beer was contaminated at some point after brew-day, and that the beer has been exposed to significant levels of oxygen. Some mould growth is not uncommon in the first few weeks of a wild ferment; mould lasting past that point, or appearing a any time point in a conventionally brewed beer, is something I personally would consider to be a sign that the beer should be dumped.

Preventing And Managing Mould

Preventing mould in conventional brewing is easy - normal brewing practices should kill any spores present in the grain or hops, and limiting oxygen exposure once primary fermentation is complete will prevent the germination and growth of any spores which enter the beer after brew-day.

If adding fruit, "punching down" any floating fruit (keeping the fruit below the level of the liquid), only adding fruit to secondary in an oxygen-impermeable fermenter (e.g. a carboy with an airlock ), and purging the airspace with CO2, will prevent mould from growing. As an added precaution, fruit can be washed in a mixture of water and hydrogen peroxide prior to adding to beer. To do this, add ~1/4 cup of 3% peroxide (from your local pharmacy) to a sink full of cold water. Soak intact fruit for ~5 minutes, then rinse, freeze/puree (or whatever you do prior to adding fruit to your beer), and add to the beer as normal.

For wild ferments (coolship ales, etc), preventing mould is equally simple. Ferment in a carboy or other oxygen impermeable container, using an airlock once primary fermentation is complete to exclude oxygen. Purging the headspace with CO2 after any transfers or sampling will further limit any mould growth, and has the added advantage of preventing acetic acid formation. In simple terms, if you can prevent Acetobacter from turning your beer into vinegar, and Brettanomyces from turning your beer into nail polish remover, than you can keep mould from growing.

If mould begins to form your options are more limited Fruit beers with mild contamination can be punched down and the headspace purged; if the mould doesn't return you should be OK. For other beers any mould growth should be considered a serious problem - simply removing "floaties" will not help as a small mould island will be connected to an extensive network of near-invisible fibrils which will remain behind and continue to grow. Personally, I would dump any conventionally brewed beer with mould on the surface (after confirming it is mould and not yeast or trub islands). Again, prevention through limiting oxygen ingress is a better choice than trying to remove it later.

Barrels can be particularly hard to deal with, as their higher oxygen permeability aids in mould growth. Suflating empty barrels, keeping them properly filled, and using either a tightly fitting bung or quality airlock, will prevent mould growth in most cases. Commercial brewers and vinters will usually toss barrels that develop mould; a practice we homebrewers should emulate.

In Conclusion

Long story made short, you cannot tell whether a mould is toxic or not, short of subjecting it to laboratory identification. Given that mycotoxins can have cumulative effects, the ease of preventing mould growth, and the relatively low costs of homebrew-sized batches of beer, best practices are simply to dump any mouldy beers...with the possible exception of fruit and wild beers, as discussed above (and even then, an ounce of prevention is worth a pound of cure).

Wednesday, 3 August 2016

New Video - Freezing Yeast

After 8 long months I have finally completed the next video in my "Your Home Yeast Lab Made Easy" series - this one on using refrigeration and freezing for storing yeast. Both methods use materials readily available around your home.

There is not much to add in this post to complement the video. If you have any questions or comments, post them here or on the video.



My YouTube Channel
Your Home Yeast Lab Made Easy Series

Saturday, 2 July 2016

Helles a good radler

My wife is not a beer fan. This is both a blessing and a curse. A blessing as my beer lasts longer, but a curse as I cannot share the fruits of my hobby with her (although she does love the fruits of my cider and wine making).

But my wife (and I) does enjoy a radler. For those who haven't encountered these, they are a common beverage in Germany and Austria, usually served in cafes catering to cyclists, and are made of a 50:50 mix of a light beer (often a helles, although some are made with wheat beers or pilsner) and a ctirus soda (like 7-up, only a stronger citrus character).

While refreshing, radlers have two major issues (from my point of view): 1) Mixing the beer with the soda decreases the alcohol content too much, and 2) the balance is too sweet for my tastes.

So I tried to make a radler that my wife would like, but which would also fit my tastes better...I achieved the later, but the former goal was not quite achieved.

"Recipe"

Recipe in quotes as this barely counts as a recipe:
  • ~17L of a light lager (I used the Helles blogged about in my previous post, but any light lager would work)
  • 1/4 tsp of potassium metabisulfite
  • 10 g of potassium sorbate
  • 4 cans of frozen juice concentrate (enough to make up ~10L of juice; I used pink lemonade)
Transfer the beer into a carboy and mix in the metabisulfite/sorbate - this will stabilize the beer and prevent any residual yeast from consuming the sugar in the juice concentrate. Then add the concentrate, mix and carbonate. That's it!

Tasting Notes:

Appearance: Slightly darker, but much hazier than the Helles this beer was made from. Head retention is poor - likely due to fruit oils in the frozen juice concentrate.

Aroma: Pink lemon-aid, citrusy and fresh. The underlying malt-note is present, but plays second fiddle to the citrus.

Flavour: Here is where I succeeded...and failed. The citrus note is strong and upfront - as with most raddlers it is the focus of the beer. Beneath that is (as you would expect) the sweetness imparted from the juice. But where this recipe deviates from the normal raddler is that there is a strong beer note, including a detectable hop bitterness. To my palate this greatly improves this beer, making it more balanced and with less apparent sweetness than is normal. Likewise, the maltiness of the helles comes through, adding a nice counter-point to the citrus character of the lemonade. To my wife's palate, this is where I went wrong - its too "beery", which means that there is too much hop bittnerness. Aftertaste is a lingering sweetness/citrus, with a hint of hop bitterness.

Mouthfeel: Not as light bodied or dry as the helles base, and far heavier than a conventional raddler, but still light enough and fresh enough to be refreshing. You can tell this was made from juice instead of soda, as the beer's body has some of the "thickness" of juice, rather than the clean/crisp body of soda (if soda can be said to have body).

Overall: For my preferences, this is far better than any commercial raddler I've had. The balance provided by the higher hop bitterness is more pleasing to my palate, while the beer retains a refreshing character. To my wife's palate I've not been as successful as hoped - that bitterness I perceive as adding balance is, to her, a strong and unpleasant note.

Next Time: Given this was supposed to be a treat for my wife I'm going to have to rebrew it more to her taste. I haven't finalized my plans yet, but next time I think I'm going to use a wheat beer for the beer base and use soda "reinforced" with frozen juice concentrate (to better mimic the soda normally used) in place of the pure juice concentrate I used in this recipe. And most importantly, I'm going to stick to the 50:50 soda/beer ratio that is normally used for raddlers - apparently that ratio wasn't decided on arbitrarily, and instead represents a good balance.