Thursday, February 21, 2013

Beer Clarity and Bitter Tasting

In the world of brewing English style bitters, how your beer looks in a pint glass is often as important as the ingredients and process used to make it. For unlike many styles where yeast haze or cloudiness won't greatly affect the flavor of the beer, in bitters in particular, suspended yeast particles can easily muddle the overall character of the beer. Unsurprisingly, removing suspended yeast via finings and/or through a cold treatment typically has a positive impact on the final product, letting the individual flavors shine. As the topic of beer clarity doesn't come up very often, I thought I would say a few words about beer finings, how I use them, and why a clear beer is a usually a better beer.

As with most things in brewing, beer starts and ends with yeast choice. While many British yeasts are known to be highly flocculative and produce very clear beer without any treatment, there are an equal number of yeasts that benefit from some type of finings. In particular, beers brewed with yeasts that have medium-to-low flocculation (or are powdery) and those that produce lots of mineral and bready flavors usually will see a sizable improvement in flavor after treatment with finings or a cold treatment. Some commonly used yeasts that fall into this category include: Wyeast 1028, 1275, 1318, 1882, and WhiteLabs 006, 022, among others. For the sake of simplicity, lets take a look and one of these yeasts and discuss some of the practical and beneficial aspects of using finings and/or a cold treatment.

If you've not heard me rambling on about the virtues of the Bedford Bitter yeast, I love the stuff. It produces wonderfully balanced, complex beer with a good mix of fruity esters and clean malt/hops. However, while this yeast is quite flocculative, it is also quite powdery. Unlike yeasts that flocculate hard and form a dense yeast cake - such as wy1968 and 1098 - powdery yeasts often retain a fine dusting of yeast particles in solution and those particles can easily be agitated back into suspension. These yeasts take longer to clarify by themselves and often impart a yeasty or muddled character to the beer if left untreated.

To get around this problem, there are a few things we can do. With the Bedford yeast, the first thing I like to do is to cold crash the beer. Essentially, this is as simple as waiting until the bulk of fermentation is complete and a thorough diacetyl rest has been completed - say, by day 10 or 12 - and then quickly bringing the temperature of the beer down to near freezing for a few days. This serves to drop the remaining yeast, proteins, and hop material out of solution and help solidify the yeast cake. After the cold crash, I'll rack the beer into a C02 primed keg and let the beer condition at room temp until the keg is ready to go on tap. Weeks later, by the time the keg is thoroughly chilled and ready to drink, the beer is usually beautifully clear. However, if there is still yeast left in suspension, I'll add finings.

Of all the finings available, I prefer to use isinglass. While it is harder to find than something like gelatin, I have found that isinglass (sold in powdered flakes) clears as fast as the other finings and has less of an impact on the final flavor of the beer. To use isinglass, I gently rehydrate about 3-4 grams of the powder in 300ml of sterile water or beer (beer has a lower pH) and wait until it is completely dissolved before adding it to the chilled beer. A gentle shake helps mix everything together and the beer is left to clear for a week+ time. In my years of using isinglass, I have never encountered any issues with off flavors and the resulting beer is exceptionally clear. Moreover, gelatin is another effective fining agent and is simple to use too. In short, heat a small amount (350+ml) of sterile water on a stove to around 170-180F and add in around a half packet of gelatin (around 4 grams per 5 gallons) and let dissolve. Do not boil. After letting the liquid cool, add it into your chilled beer and give it a week or two's time to fully clear.

While gelatin works very well, I have noticed that using too much of the stuff can impact the flavor of the beer, bitters in particular. Not only does it strip away some of the hop character (best to use it before dry hopping), but too much gelatin can also alter the malt profile by increasing the perception of specialty malt/caramel flavor. Moreover, as is the case when using any fining agents, using too much gelatin can strip the beer of proteins, leaving it thin tasting and with poor foam stability. Although, I'd say it is better to have a clear beer with some character missing than to drink one that is muddled and yeasty. Aside, some of the other finings that I've tried and are commercially available include, Polyclar, Bentonite, and Sparkolloid. The first two are effective at removing chill haze and some phenolic off flavors, while Sparkolloid is particularly suitable for removing stubborn yeast. These can all be added to the secondary or keg, however, they are really best reserved for wine making.

Lastly, it should be mentioned that fining use can largely be unnecessary with good brewing and fermenting processes. A proper mash pH and a healthy ferementation goes a long way to help ensure you end up with a clear beer, as does achieving good hot and cold breaks. Cooling your wort very slowly can impact beer clarity for the worse, as does having too much break material in your fermenter. As for kettle finings, I like to use Whirlfloc in my kettle - half a tablet at 15 min from flameout - and Irish moss is equally as effective.
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No finings needed here
Golden Bitter : Special Bitter 

Appearance - Pours a (nearly) brilliantly clear, golden-amber color with a bubbly, two finger white head with good retention and lacing.  

Aroma - Orange zest, apricot, and floral hoppiness with some sweet malt character. Not much perceptible caramel or yeast character. Rather hoppy for your average bitter. 

Taste - First impression is of dried herbs, apricots, and marmalade-y hops with some honeyed malt and a very light caramel sweetness. The yeast character is clean and mostly neutral, with just a hint of those rich esters I so like. Bitterness is high/firm and the beer finishes crisp and dry.

Mouthfeel - Medium-dry and goes down smooth and easily.

Drinkability & Notes - Can't complain, just a good and hoppy bitter. I wanted something along the line of a golden ale and while I am pleased with what I got, the hopping and bitterness would certainly push this towards an English IPA. This beer shows off the First Gold hops quite well - a great beer for the coming spring - although I did get more apricot and herb character than pure orange in this batch. Only thing I'd change for next time is to drop the bitterness closer to 30 IBU, as the bitterness is a bit firmer than I like in my session-style beers.

 5.0% ABV, 40 IBU, WLP006 Bedford Bitter. Recipe Here

9 comments:

  1. Another great and informative post.

    I've seen a couple of people online suggest that Wyeast 1099 (which has the advantage of being available year round) is essentially equivalent to the Bedford yeast. In your experience, is that accurate?

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  2. Sorry for the back-to-back posts, but I forgot that I had a second question!

    This one is about cold-crashing. If I plan on bottle-conditioning a batch, is there any advantage to cold-crashing it for a few days while it's still in the fermenter, or will putting it in in the fridge after it has had time to condition and carbonate in the bottle produce the same results?

    Thanks again!

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  3. Yes and no. Both the Whibread (1099) and Bedford yeasts have some similarities - clean, lightly fruity, and are good with hops/malt - but the yeast profile you get from is rather different. Whereas the Whitbread has a very dry, clean, almost tangy type of flavor, the Bedford is fruitier and can produce some diacetyl, which in (very) small amounts can give a slight 'rich' quality to a beer.

    Given the difficulty of sourcing the wl006 yeast, 1099 wouldn't be a bad sub, although there are more similar tasting ones out there. British II (1335) is probably the closest I've tried.

    Per the cold crashing, it still is of value for bottling as it helps drop excess yeast... which can be good for bottling so you don't end up with a ton of yeast in the bottle. However, it is not at all necessary. If you got the time and the space, I'd say it is worth doing, but nothing to stress over.

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  4. Thanks for the response! I'll need to give 1335 a try if I can't get my hands on the Bedford.

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  5. I generally use 2tsp gelatin in 200ml water into chilled beer. It's easy and works well, though like you I do worry about stripping hop character. I've only noticed this in one beer so far, a very hoppy American Pale Ale.

    The only yeast I regularly use which I can depend on to completely clear by itself is the Fuller's strain - in fact beer from that strain seems to me to be clearer with no finings than many other strains are with finings.

    Sean

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  6. Great article Will and your comments about precipitate content potentially muddling beer flavor resonate fully with me.

    I have been puzzled by the continuing service of so much cask (real) ale in North America in cloudy form. In England where I first drank cask beer, it was never like that.

    A very light haze doesn't bother me but so often the main taste in these beers seems to be yeast... Sure, one expects that in weisse and weizen styles, but pale ale and IPA (porter too IMO) belong to a different tradition. I am sure you have noticed as well the trend even to serving some chilled and fizzy craft beers in hazy form. I just don't get that, i.e., it is not (IMO) just an aesthetic thing.

    Even when the yeast is well-clarified out of the beer you still taste it but it stays in the background. I don't say every cloudy beer is unpalatable and some end up being acceptable, but a regular practice of requiring the beer to drop beer with the various techniques you described is in my view, not just a boon to quality but is in accordance with English historical beer tradition. Thanks again for this excellent posting.

    Gary

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  7. Hi guys. On the question of fining. I fine my light coloured beers with gelatine at a rate of .08 grams per litre, which is about 1.5 grams for a 5 US gallon batch. The only thing I notice is that the gelatine strips colour even at this low rate
    Cheers -Cliff.

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    1. That is a quite low rate of finings. It is interesting you have noticed a reduction inn color. I can say I've noticed such a change in my beers, although sometimes the finings make the beer seem darker, as the (lighter) yeast haze is removed.



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  8. The colour stripping was more obvious when I was fining darker beers. In the past I have used up to .25 grams of gelatine per litre but the lower rate clears the beer just as well.
    Cliff.

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