I've had a number of queries about how I go about brewing beer. I've always held off
describing things, since I know that my methods are seriously sub-optimal. Still, maybe
that's a reason: almost every brewer ends up with tradeoffs, and maybe somebody reading this
page can give me some ideas on how to improve things.
The photos here show the progress of Brew 88
and Brew 89, which I started on 24 September 2006, though the
preparations started earlier.
The photos here are relatively small to improve download time. If you click on any, you'll be
taken to the correct place on a page with all the photos for the day, including many more of
the brewing process that are not included here. If you click on any of those, you'll get a
full 6 megapixel photo.
The yeast
A few days before the brew, I need to make a decision about what yeast I'll be using. In many
cases, I'll use the yeast from the secondary fermentation of the previous brew. That's what I
did with Brew 88, which uses the yeast
from Brew 86. For Brew 89 I dug out an
old yeast starter from the fridge. It had been there since 9 February 2005, over 18 months,
and it took a few days to get the starter working. Unfortunately I didn't think the take
photos of this, so I'll add them later. The process is:
Take about 150 g of BiLo “Lager” homwbrew lager kit and boil it in a litre of
water.
Let it cool down, shake vigorously, and add the yeast. Some people add yeast nutrient at
this point, but I think there's probably enough in the concentrate.
Wait until fermentation starts. Some people use a bottle with an airlock, but I put my
starters in a sealable 1.5 litre juice bottle:
That way I have much better control over the state of fermentation. When opening the
bottle, the gas escapes, and you can detect that even if there's very little. I haven't
had problems with the bottles exploding, though potentially that's a danger.
The extra water
One problem I have is that my vessels aren't large enough. When I started brewing, I aimed
for 25 litre brews, but full mash brewing is a lot of work, and 25 litres don't last very
long. So I cheated and gradually increased the volumes until I got to the current situation,
where I brew about 50 litres at a time. I'm aiming for 54 litres, which is enough for 3 Corny
kegs.
The trouble is, my boiling pot is “40 litres”, measured at the outside. It's
almost impossible to boil more than 35 litres in it. So I boil another 20 litres (to sterlize
it) a couple of days before and put it in a fermenter to keep it clean. Note that it takes
about 24 hours for this much water to cool down to room temperature.
The grain
I do all-grain brews, usually (as today) 90% pale ale malt (base malt) and 10% caramel malt to
give a bit more flavour (in this case, Joe White Maltings Caramalt, 50 EBC). I crush it
myself with a modified Italian grain crusher, driven via a shaft from battery powered electric
drills. You can get these for as little as $10 when they're on special offer, which makes
them much cheaper than the mill. The average battery lasts for 2 to 3 kg, so for the 9 I'm
aiming for I need a number, or alternatively to recharge them before continuing:
I weigh the malt into plastic containers and then crush into the provided far-too-small
container, emptying it frequently into another plastic container:
As a result, I had the rest of the grain crushed
at Grumpy's. The results are pretty much
indistinguishable. The first photo is from my mill, the second from Grumpy's:
For this brew, I tried a slight modification of techniques described in Hubert Hanghofer's
book “Bier brauen nach eigenem Geschmack”. This is a German-style multi-step
infusion mash:
10 minutes at 57°.
45 minutes at 63°
45 minutes at 72°
Clearly temperature measurement is important. I use a thermocouple-style digital thermometer
which is accurate to about 1°. This is more than enough, since it's almost impossible to get
the temperature of the mash consistent to less than 2° or 3°. The thermocouple reacts in a
second or two, so it's also useful when stirring to identify how even the temperature is.
This temperature difference is needed to make up for the cold malt, something that is more
difficult to calculate than you might think: none of the commercially available brewing
programs that I know properly take into account the thermal mass of the vessel, which in this
case is as much as of the water.
There's always a problem with mashing for light-coloured beers: the mash pH tends to be too
high, especially in towns with hard water. This is why Dublin beers are so dark (the dark
malts tend to be more acid), and why until about 100 years ago Munich beers were dark. It
wasn't until 1842, when the Bavarians started brewing
in Plzen in Bohemia (which has very soft
water), that they were able to brew really light beers.
I brew with rain water, which has an order of magnitude less minerals even than Plzen, but
past experience has shown that the pH has still been too high, so I add 2 grams of citric acid
to the water to get the optimum pH for mashing.
The complete photos show how easy it is to get different temperature readings depending on
where the probe is.
In this photo, apart from the fact that there's more liquid, it also looks different: it's
milkier, showing that gelatinization has occurred. In this step, 45 minutes long, the
β-amylase breaks down the straight chains of the starch into maltose and other products.
I could have heated the pot instead of adding hot water, but it would have taken 10 minutes,
the same time as the 57° rest.
72° rest
After 45 minutes, the temperature has dropped to 62°. I heat over a 5 kW gas flame for 12
minutes, after which time the temperature has reached 72°:
I leave the mash at this temperature for another 45 minutes for the α-amylase to break
down the branches in the starch.
78° rest
Many German mashes then suggest a “mash-out” at 78°, about the hottest the grain
should be allowed to get. I've never seen enough reason for this, so today I omitted it.
Sparging
At the end of the mash, most of the starch will have been converted into maltose (about 7 kg)
and other breakdown products like maltotriose and maltodextrin. The former can be broken down
by some yeasts, and leaves a vague sweetness in the beer when fermented with other yeasts; the
latter gives “body”. The next step is to separate the wort from the grain. This
is called “sparging” in English and “läutern”
(“purification”) in German; many English-speaking brewers misspell this as
“lautern” or “to lauter”. That's incorrect: a is not a valid
substitute for the letter ä. if you can't write ä, write ae instead
(i.e. laeutern). The word is pronounced almost exactly like the English
word loiter. But why use a German word when there's a perfectly simple English word?
The Americans make a useful distinction between lauter and sparge: the former
is used to mean any way of separating the wort from the grain; the latter is used to mean the
rinsing of the grain to perform this function. To the best of my knowledge, the British
brewing tradition does not use the word lauter: it doesn't figure in the Oxford
English Dictionary, which has just about every obscure word known in English, so I suspect
this is indicative of the German influence in US brewing.
Of the 25 litres of water that I put into the mash, I'll get about 18 out again; to make up to
the boil volume of 35 litres, I thus need another 17 litres. They need to be at 78° (the
magic “maximum” temperature beyond which your wort turns into tar, or at least
gets bitter from tannins extracted from the husks). The correct way to do this would
obviously be to have a tank of water (so-called Hot liquor tank or HLT) to
deliver the sparge water. But I don't have one, so I boil water in saucepans and then cool it
down to 78° with tap water:
The problem with this is that it's not in the mash vessel. This is one of the biggest
limitations of the fact that I started with 25 litre brews: the mash tun holds only about 15
litres, much less than I've been mashing. So I need to transfer the mash to the
“filter” tun, not at all optimal, since the wort can oxidize at this temperature.
But that's what I currently do, trying to avoid too much splashing:
I then drain the wort into two saucepans, which I fill alternately. The initial runnings
contain rests of grain and are quite cloudy; I pour them back into the sparge tun until they
become clearer:
At the same time, I take a sample for measurements.
My method has a further problem: I boil the wort in the same pot in which I have mashed, so I
need to pour the rest of the mash into other pots until I can sparge it, and then clean the
pot before boiling.
First wort hopping
Traditional brewing techniques bring the wort to the boil and then add bittering hops
and boil for an hour or so, adding aroma hops (frequently a different kind of hop)
shortly before the end of the boil. The names are indicative of the purpose of these hops.
Recently I've been trying a technique called First Wort Hopping, where some hops are
put into the wort before the boil. This appears to have originated in Germany, where it's
called Verderwürzehopfung (which is not a direct translation: “Verderwürze”
means “Front wort”, not “First wort”). In this case, I used 40 g of
Australian Tettnang plug (3.9% alpha acid) for the first wort. While sparging, I put the hops
into a blender with some of the wort and reduced:
After sparging about 10 litres total, I started heating the pot. The temperature rises only
slowly, partially because of the additions of additional freshly sparged wort, and partially
simply because it's a lot of liquid.
Sparge, continued
The sparge takes a long time, in this case 40 minutes. After all the initial wort has been
drained, I perform the real sparging:
The initial pH of 5.5 is slightly higher than I'd like (5.4 would be better, so I'll add a
little more acid next time), but 5.8 is fine for the final runnings, which were a little
stronger in sugar (3.5° Plato) than I would have liked (I'd aim for about 2.0°). That's
almost certainly because, due to the size of the pot, I couldn't sparge as much as I would
like.
The boil
Some time later, the wort comes to the boil. Initially there's a lot of scum (“hot
break”, which the Americans also call by the German name “Trub” (correctly,
“Heißtrub”, related to the German word “trüb” meaning cloudy)).
That's mainly protein material which will later precipitate out. In the second photo, taken
11 minutes later, most of it has disappeared:
Now's the time for the bittering hops. On this occasion I used 35 g of Australian
“Pride Plus” with a whopping 13.0% alpha acid, again chopped in the blender.
After boiling for about 40 minutes, I add the wort cooler, a coil of copper pipe through which
I circulate cold water:
Copper can react electrolytically with the aluminium of the pot, so I don't put it in at the
beginning. On the other hand, the most critical time from the point of view of sanitation is
from the end of the boil until fermentation is nearly over, so I want to ensure that it's
sterile. So I boil it in the wort towards the end.
Water is in short supply in South Australia (“the driest state in the driest
continent”), particularly this year. Normally I connect a hose back out to the water
tank outside, so that we don't waste any water (see my domestic
water supply page), but at this time of the year we collect more water from the roof than
will fit into the tank, so the question would just be whether the water overflows the tank or
goes straight down the drain. I take the easy way out and put it straight down the drain.
Ten minutes before the end of the boil, I add the aroma hops, in this case another 50 g of the
same Tettnang that I used for the first wort hopping.
Aeration
At the beginning of the fermentation, yeast needs oxygen to be able to grow. Normally this is
done by aerating the wort. In my case, though, since I'm adding about one-third of water, so
I aerate that instead:
After 20 minutes, the wort is at room temperature. By comparison, without the cooler it would
take about 24 hours, during which the wort would suffer in quality. Further material
(“cold break” or “Kältetrub”) has separated from the wort:
I rack most of the wort into two fermenters (14 litres each), leaving behind the dregs. For
Brew 88, I use the old fermenter from the secondary fermentation of
Brew 86, which has enough yeast to start the fermentation.
With a hydrometer, I measure the strength of the wort: 17.1° Plato, rather less than I was
hoping for. I dilute it with 10 litres of aerated water; with the remaining wort to be added
tomorrow, this should give a total wort strength of 10.6° Plato, rather weaker than the 12.0°
I've done in the past. The background for this is that I've been drinking more beer lately
since installing a keg, so this compensates. I'll find out later whether it tastes
“weak” or not.
The dregs
There are still about 4 litres of wort left behind with a significant quantity of break
material and hops. That represents about 6 litres of beer, clearly too much just to throw
out. On the other hand, from a point of sanitation this is about the most critical part of
the whole brewing process. I can't just put it through a sieve and add it to the fermenter.
Instead, I put it into another pot and bring it to the boil, then leave it to cool before
adding it to the fermenters:
Finally, I put the fermenters in the fridge and attach the temperature sensors for
my fermentation temperature control system. Then, and
only then, I put the water in the fermentation airlocks:
The second photo shows that fermentation is well under way. The brown blotches are the yeast,
which is mainly top-fermenting, though not as strongly as German ale yeasts are. I don't know
any special name for the foam in English; in German it's called Kräusen, pronounced
roughly Kroysen (and not “Krausen”; again, if you don't have an ä, it's
spelt Kraeusen).
Racking
These brews were fermented at 18°, two degrees lower than normal, and the difference made
itself felt. Normally I rack the beer to a secondary fermentation after a week, but this
time I waited 9 days:
I used to use this for pitching new brews, but nowadays I use the much cleaner sediment from
the secondary fermentation instead. That has the danger, of course, that I'll get
progressively less flocculent populations.
At this point I also take a sample of the beer, that now tastes recognizably like beer. I
measure the refractive index and pH:
In this case, brew 88 (left) was “normal” (5.6° Plato,
pH 4.4), but brew 8 was higher than eexpected (7.5° Plato, pH 4.6).
Maybe the pitching rate wasn't high enough. I expect things to settle in the secondary
fermentation.
What's wrong with this picture?
As I said at the beginning, this setup is not ideal. Here's a summary of what I think needs
to be improved:
Vessels need to be larger: I need a boil kettle that will take at least 70 litres, and
the current boil kettle needs to become the mash tun (in other words, it needs to be fitted
with a manifold, so that I can sparge directly).
I need a hot liquor tank for the sparge water.
I need a better way of separating the wort from the dregs.
Why haven't I done this yet? I'm still thinking about automated mash systems, and what I
decide there will determine what kind of equipment I use. In particular, maintaining accurate
and uniform mash temperatures is a problem, and I'm not sure that the RIMS
(Recirculating Infusion Mash System) and HERMS (Heat Exchanged Recirculating
Mash System) systems that I have seen will solve this
problem. Some articles agree
with me. Until I can get my head round the issue, which will probably require more
experimentation that I would like, I'll continue with the current imperfect system.
