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Protein and Clarity: An Entirely Opinionated Digression
by Jeff Irvine
The subject of protein and its influence on the brewing process has been
covered in most home brewing guides. I am prompted, however, to thrash this
subject once again as I feel that worries about clarity often push home brewers
unnecessarily in the direction of 'thin ' beers.
First the theory. If you belong to those that are repulsed by any mention of
a Latin sounding word, insert two fingers in your throat and return at the next
paragraph. I'll keep it short. Promise. Proteins are built up of amino acids.
They are of different shapes and grouped accordingly. What they do have in
common is their ends. They have like a 'plus and minus' side that can always
link up with another one. As they get slapped together, they build longer and
longer chains. The chains twist like a slinky and all of a sudden 'bingo', they
figure out a way to connect other than the regular plus-minus way and you've got
...a tangled slinky! A particular childhood intelligence test that I never
managed to solve. If the slinky gets long enough and tangled enough they
approach the form of a ball and are called 'globulins'. This is easy to remember
because it sounds like 'hob-goblins', and you want them in your beer as little
as you want them hiding in your bedroom closet at night. If they are shorter and
less tangled they are referred to as 'albumins', which is a pleasant enough
sounding word and could well be the name of a former first-baseman for the Mets.
This degree of getting tangled up is referred to several ways in the literature.
'Stereoscopy 'is one. 'Dimensions ' or 'Structure' is another (primary,
secondary, etc., and in this world there are four dimensions-heavy). 'Alpha' and
'Beta', and 'Helices' are a third. But don't let that confuse you. They are
really only talking about how tangled their slinkies are.
How Do We Control Proteins?
Starting in chronological brewing order: 1) The 'premash'. This is the
proteolytic stage (ah! I can see you sneaking out of the room again. 'Lytic'
just means 'breaking- stuff-up'. Whenever you see it on the end of a word it
means breaking up the stuff in front of it, as in...'My three year old son is 'toylytic').
2) The 'hot break'. The proteins denaturing (gettin' unnatural) and falling out
of solution. 3) The 'cold break'-ditto. 4) Fining agents.
The proteolytic stage occurs at lower temperatures, and the enzymes
performing it should denature at higher temperatures. Miller in his fine and
extensive book, is the first author writing for home brewers, that has addressed
the fact that proteolytic enzymes have temperature specific maximums. This means
simply that at different temperatures you will break down different sizes of
twisted slinkies. The Hob- Goblins at higher temperatures, and Al Bumin at
lower. I've never rigorously tested whether or not there is a practical
difference within the home brew set up, but it is an interesting thought. I
think in general most advice that adds worries and complicates the brewing
process, is well worth testing within the confines of your own set up, because
some of it is derived from a brewing industry that has entirely different aims
than the home brewer.
The hot break comes from the combination of the 'tannins' in your hops with
protein. When asked how long one should boil, I generally reply ' Until the hot
break'. If that takes three hours, let it. Dilute your wort later instead. What
you should see are distinct little clumps in an otherwise clear liquid A
transparent cup, or white background (as enamel) serves just fine. Scoop some
out and train (and trust) your eyes.
As I understand it, the first 35°C (about 60°F) are the critical part of
the cold break. In old breweries, you can find rooms where the floor (and about
a foot up the wall), are covered in copper. The boiling wort was simply dumped
on the floor, and then left to cool. They stripped those first degrees and then
there was no worry about the rest.
Finings (Isinglassirishmossdiatamaciousearthpolyclearbentonitehazelwhathaveyou),
I will leave to someone else to discuss. Leave it to say that they all cause the
removal of proteins.
Why the Worry About Proteins?
On the downside, proteins in excess are meant to be responsible for a
characteristic bitter taste and cloudy beer. This problem has been accentuated
this century with the advent of artificial fertilisers, and higher protein
yields in grain. Result: happy bakers and unhappy brewers. Hopefully, increased
consumer awareness, and the current rising trend of interest in sustainable
agriculture will lead to greater availability of brewing friendly grains (brew
beer! It's good for the environment!).
Now about what proteins are good for. They are responsible for the lovely
creamy head, which is a joy in itself, but more importantly, they give the BODY
of the beer. That taste that curls all the way round your tongue, gently
marrying the other flavours into a beautiful symphony. Or to carry the musical
analogy further, if the sweetness and the bitterness are the booming bass tones,
and the aromatics of the hops are tootleing flutes on top, so are the proteins
the long strokes of the cello that tie it all together and fill the empty spaces
between. Without them, the beer is thin, and the other tastes 'elbow' against
each other.
So What's the Point?
If you ask a brew master where his best beer is, he will (if he's honest)
immediately point to his lagering cellar, before entering the filter and the
pasteuriser. I never cease to be amazed at how good this unperverted product is
before becoming something quite mediocre on the shelf. If you drink directly
from the lagering tank of any professional brewery, it is not 'star bright'. It
is not clear. It is just delicious. It turns out that these guys know what
they're doing, it is just that they are required to make something that you can
transport, and store under (for beer) horrifying conditions for long periods of
time, and always taste the same. In order to do that, all manner of unstable
things must be removed, and one of those that follows along is proteins. As a
home brewer, you don't have these constraints, and can allow your beer to attain
all the full flavour that has given this fresh product the well earned nickname
of 'liquid bread' in so many cultures.
The most amazing bottled beers I've ever tasted were the beers of
Czechoslovakia before the fall of the Berlin Wall. These beers were date stamped
at filling and had a SHELF LIFE OF TEN DAYS. Not that they turned into rot after
that, but the protein content was so near the saturation point, that after a
couple of weeks, great strings of proteinaceous material began to precipitate
out in the bottle. It still tasted fine, but nobody wants to drink a glass full
of maggots. As one tipped out a portion from the bottle, and righted it again,
bubbles would climb up into the neck of the bottle in different geometric
shapes, and STAY THERE. There was that much protein. For a simple fellow such as
myself, this can provide HOURS of fascinating entertainment (Hey, look. They
haven't broken up YET!').
The reason I am going on and on about this is that I find too many home
brewers (spurred by competitions where clarity is an important criteria of
judgment) may err in the direction of thin brew. There is a good reason why in
many traditional brewing areas, the favoured drinking receptacle is the stone
ware 'stein' (which means 'stone'), and where glass 'steins' are used, they are
often fluted or embossed on the surface to cast the light in all manner of
directions- The best beers simply might not be clear.
I would invite each of you to perform the following experiment. Take a beer
in it's natural state, and clear it three different ways (finings introduced in
the boil will require multiple boilings, but hey! what a homebrewer won't do!).
I find that four different beers is plenty for a comparative tasting ( Five
stretches just beyond my taste memory, and I have to keep going back and forth
until I'm sloshed). Now mark up some opaque receptacles with numbers (small
plastic mugs will do just fine). Mark up some protocols on paper and then call
up some of your friends for a tasting. Now quickly BOLT THE FRONT DOOR, AND GO
HIDE UNDER THE DINING ROOM TABLE!! You see, this is a task that is not
particularly difficult to recruit volunteers for. The number of UNinvited guests
may number anywhere from one, to most of the local township. Now, when the
guests arrive, mark up a bunch more mugs and try and get rid of as many extra
people as possible ('Uh, Dave? Your wife called. You left the bath running.').
Now what I want you to do is at least a 'single blind study' in which none of
the people tasting know which beer is which. Hopefully you can do a 'double
blind study' where the person serving and tallying the protocols doesn't know
which is which either- The theory being that the person knowing, can
subconsciously influence the subjective tasting of the others. My experience has
been that when it comes to the pride invoked in home brewing, that influence is
about as subconscious as the Desert Storm Operation ('Heey, THAT one's not bad,
eh? Yes sir a little patience and good ingredients go a long way, huh? By the
way, I think THAT one was lagered TWELVE WEEKS.'). Another interpretation might
be, a 'single blind study' is when you accidentally poke yourself in the eye
with the neck of a bottle, and if you are having a 'double blind study', you're
swilling, not tasting. Now it would be very good if you could be a part of the
tasting, and someone else the 'blind' server and vote tallier ('O.K. Dave, you
can stay. But let me show you something I want you to do. It's REAL
important.').
If you do this simple experiment, and particularly pay attention to trying
not too look at the quality of the head at the first taste- just use your mouth
and nose ( though I must admit, when only one of them gives you a Chris Cringle
moustache you might get a clue what's going on), You may find as I have ( and
included filtration-Nuclepore 0.4 micron cartridge), that the batch that you've
done nothing with at all, unanimously wins. Again, and again.
Now, What Have We Learned Here?
Outside of the fact that Dave doesn't know where he lives, probably nothing.
I've tried to point out that proteins come in all shapes and sizes. The bigger
ones (Hob Goblins), are probably a good thing to remove, while the smaller ones
are beneficial to taste, head retention, and yeast nutrition. My ideal beer is
just on the point of saturation of proteins. I try and cram as many as possible
into solution, and if I err a bit, I prefer it to be a slightly hazy well
tasting beer, than a thin tasting clear one. To this end; 1) If you are doing a
proteolytic rest ( And with most grains it's probably not a bad idea), you
should pick your temperature and time (not too long and not too low), and then
fire that baby up and get out of there. Next time try something else if not
satisfied, but don't spend 'hours' at these low temperatures. 2) Get a good hot
break! 3)Try and make your cooling effective over the first 50° or so. If
you're using a counter flow cooler outside the kettle and it goes a bit slow,
you might want to make sure the stuff in the boiler stays hot and doesn't slowly
cool down by itself 4) Unless you are faced with the same problems as commercial
breweries (long transport, variable temperatures, and long storage times), I
can't see why one should ever have to use fining agents.
If you have a cousin's, husband's, workmate's, sister or anyone else who can
get you into the lagering cellar of a brewery to taste the 'natural stuff', DO
IT.
If your friends are not yet educated in the finer points of beer, and will be
horrified looking at a cloudy beer, buy some good stoneware mugs to serve them
in. They are the superior drinking vessel, as they insulate well and allow you
to maintain your lagering temperature through the whole glass, and even cool the
vapours, so you can stuff your nose into a real 'lagering cellar' smell. You'll
find the edge is ergonomically designed for your lips, and good ones even have a
little 'ski jump' at the end to splash that swallow evenly over your tongue. If
you are really an admirer of good beer colour, you might try pasting a picture
of a pretty beer on the side o your mug, at least that way Dave will know it's
yours and won't borrow it and break it...again.
References:
1) 'Off the Top of My Head, and By the Seat of My Pants' by Dr. Pivo.
Please note: The above comments are entirely the author's opinions plus those
of some he knows who brew a 'damn fine drop'. No offense is intended towards
people who enjoy using finings or making attractive looking beer. Neither is any
offense intended towards anyone in the brewing industry, who I have found
infinitely kind and helpful. Lastly no offense is intended toward anyone named
'Dave', and certainly not my neighbour, even though that happens to be his name.
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