Brewing Science: Gelatin & Clearing Beer

I was bottling my Merlins Mild this Friday, and while preping my gelatin, I realized it has been a while since I did an article on brewing science.  The two thoughts merged, leading to this article on how gelatin helps clear beer.

Firstly, a brief outline of how I use gelatin for fining my beer.  There are a lot of other methods out there, but this is what I have found works for me.

1. Cool the beer as cold as you can (crash cooling), you can do this in a fermenter or keg.  The colder it is, the clearer the final beer will be.  I've had good results at 18-20C, but for crystal-clear beer you need to be at 5C or cooler.  Don't freeze it...
2. In a lidded pot, add 1 packet (1 tablespoon) unflavoured gelatin to 250-350 ml (1 to 1.5 cup) boiled and cooled water (20C/room temp or colder).  Let sit 20 minutes to 'bloom'.  You'll notice that the gelatin will swell, from small prills to balls 0.5-1 mm in diameter.
3. Heat gently, in a pot covered with a lid, to 77C (170F).  Remove from heat, keeping covered, and let cool to room temperature.
4. Add to top of cold beer.
5. In 2-3 days, beer should be super-clear.  You can bottle at this point.  If in a keg, you can begin carbing as soon as the gelatin is added.

Note that pre-boiling the water is optional, but this does sanitize the water.  It is important to add the gelatin to room temp or colder water for blooming - warmer than that will lead to clumping and incomplete blooming.  It is absolutely essential to heat to 77C; a little cooler and the gelatin will not solubilize, a little warmer and it will gel in your beer.

The science behind how this works can be found below the fold...

A brewers life, animated

I'm sure all you homebrewers out there can relate to this.  Depending on your boss, this video may or maynot be work-safe.  It is not SWMBO-safe.

 

Merlins Mild - First Brew of 2013

Garage Brewing in January.
Merlin may be mild; the weather isn't!

You'd think by now I know better - 17 years of homebrewing and I still don't brew an extra batch near Christmas.  Once again, friends and holidays have left me with nothing but a few pints of Bad Santa in a keg, and two bottles of beer I didn't mail out as Christmas gifts.

So once again I find myself short on beer and in need of an emergency brew session. This weeks beer is a rapidly fermenting (and thus, quickly on-tap) style of beer called a mild. Rare in North America, this beer is a lower-alcohol brew that features a lot of grain and hop flavours, but with a level of hoppiness below what is typical of most English ales.

This mild is darker than most - the brewshop didn't have crystal 60, so I replaced it with an equal amount of crystal 80. The alpha acids of the hops were also higher than expected, so I adjusted the recipe to hit 20IBUs and threw the leftovers in at flameout to add some aroma. This is also my second time using yeast from the guild yeast bank that I manage. So the colour's a bit darker, the flavour a little more towards caramel than sweet, but it should still be a fine brew.

This batch is named "Merlins Mild"; not because of any historical link to the era in which Merlin supposedly lived (although, many beers from that time may have had some similarities). Instead, I was watching Star Gate while putting together the recipe and nerded out over the name...

Recipe below the fold...

Brewing Lagers without Lagering

This video, from Brewing TV, covers a topic of interest to many brewers - how to get a clean, crisp lager beer without the need for lagering equipment (i.e. dedicated fridge + temperature controller).  This video covers three methods on how to do this.

 

Methods & results are summarized below the fold...

Book Review: Designing Great Beers: The Ultimate Guide To Brewing Classic Beer Styles

Tomorrow I go back to work, so I need to finish my review series.  I saved the best for last.

Designing Great Beers. Information on Malts: 5/5 Information on Wort Biochemistry: 5/5 Information on tops: 5/5 Information on Yeast: 2/5 Information on Style History: 5/5 Information on Style Characteristics: 5/5 Information on Style Composition: 4/5 Overall: 4.42/5

Designing Great Beers: The Ultimate Guide To Brewing Classic Beer Styles^link by Ray Daniels is, hands-down the best advanced brewing book I have ever read. While not a good book for beginners, this book is a must-read for any brewer interested in designing or optimizing recipes, what goes on in the brew pot, hops characteristics & chemistry, the history of various styles, and what goes into award-winning brews.

More Below the Fold

Book Review: Yeast: The Practical Guide to Beer Fermentation

First, let me wish you a happy new year. Hope 2013 is a blast!

The next book in my book review series is Yeast: The Practical Guide to Beer Fermentation^link, by  Jamil Zainasheff & Chris White of White Labs fame. This is not your typical homebrewing book; indeed, it is an almost-textbook about choosing, using, managing and culturing yeast.

Yeast: The Practical Guide to Beer Fermentation Fermentation Information: 5/5 Basic Yeast Handling: 3/5 Advanced Yeast Handling: 4/5 Relevence to Home Brewers: 3/5 Overall: 3.75/5

The beginning part of this book is a must read for all brewers. It covers the basics of yeast biochemistry, the chemistry and conditions that lead to various flavour and off-flavour compounds, how to manage yeast in a fermentation to produce the desired flavour profile, and how to get the most out of your yeast.

This section alone is reason enough to buy this book.

Unfortunately, after a strong start this book weakens.  Much of this is due to to attempt by the authors to cover both homebrewing and commercial beer production. This has detrimental effects - for example, in the section on stepping up yeast to pitchble amounts specific guidelines are not provided and instead we are given some general rules plus some equations to work things out for your own brewery - a situation fine for commercial operations with a yeast-lab, but out-of-reach for most homebrewers.

This situation persists for much of the remainder of the book - commercial and homebrewing advice & methods mixed together in a way which is difficult to understand & use in the context of homebrewing.  The book finishes off with a series of lab-based protocols for analyzing yeast for contaminants & yeast characteristics.  While interesting, these too are  methods beyond the capabilities of most homebrewers.

Despite those flaws, in my opinion this is a book that belongs on the shelves of all serious homebrewers.