Thursday, 30 June 2011

Accidental Efficency Jump

Over the last few Brew Day's the brew house efficiency has been a bit lower than I'd have liked, with numbers coming in around 70% or even a little less.  How the grain is crushed is probably the most important part of achieving decent efficiency.  In the past the procedure I had been using involved conditioning the malt (adding a small amount of water and mixing it well, just before milling) with the theory that this should result in less damaged husks but still produce a fine crush.  The crush has always looked good and I've never had a problem with sparging:
When crushing grain for the Vienna yesterday, I managed to bump the mill, knock the hopper over and spill about half the grain over the ground.  By weighing what had already been crushed I was able to compensate for the lost graind and measured out and crushed some more.  However the new grain was not conditioned with water first, but at the end of the Brew Day the numbers told me that I was looking at an increase in efficiency of a bit more than 5%.

It would appear that the combination of the mill roller gap setting and conditioning the malt before crushing it was decreasing and not increasing the extract efficiency.  Next Brew Day I'll run the grain through the mill without conditioning it first and hopefully  notice a similar efficiency increase.

Wednesday, 29 June 2011

Brew Day: Vienna Lager

Second Brew Day in as many days, it's cold outside and the fermenting fridge is turned down to lager temps, so making the most of it to brew a few lager beers.
Estimated OG: 1.054 SG  Estimated Color: 10.3 SRM  Estimated IBU: 29.1 IBU
Boil Time: 90 Minutes

45.5%    Vienna Malt (Weyermann) (3.0 SRM)
27%    Pilsner (Weyermann) (1.7 SRM)
24%    Munich I (Weyermann) (7.1 SRM)
3.5%    Caraaroma (130.0 SRM)
1.13g/L    Hallertau Aroma 09 [8.10%]  (60 min)    27.4 IBU
0.65g/L    Mt. Hood '10 (HomeGrown) [5.00%]    1.8 IBU      
0.043g/L    Calcium Carbonate
0.087g/L    Calcium Sulfate
0.26g/L    Calcium Chloride
17.4 billion cells/L  (Starter)  German Bock Lager  (WLP833)

Single infusion mash @ 67C.
 Other than knocking over the mill-hopper while crushing the grain and spilling half of it onto the ground, it was a mostly un-eventful Brew Day.  It was interesting to note that there was a 5% efficiency increase, most likely related to the replaced malt not being conditioned before crushing.

Tuesday, 28 June 2011

Brew Day: Munich Helles

Now that winter is here, and it's time to brew a few lagers.  Today's Munich Helles is the first of 4 that are planned this winter, one of the reason for brewing the Munich Helles first is so that I can grow enough yeast to pitch into the BoPills in a few weeks time.

Munich Helles
Estimated OG: 1.050 SG, Estimated Color: 3.7 SRM, Estimated IBU: 21.0 IBU
Boil Time: 90 Minutes

90.6%    Pilsner (Joe White) (1.6 SRM)
5.7%    Munich I (Weyermann) (7.1 SRM)
3.8%    Carapils (Weyermann) (2.0 SRM)
1.43g/L    Hallertau 08 [4.90%]  (60 min)    21.0 IBU     

0.217g/L    Calcium Sulfate
0.26g/L    Calcium Chloride
17.4 billion cells/L  (Starter)  PC European Lager ( #Wy2247)
Mash schedule was adapted from the  Hochkurz Double Decoction on Braukaiser.  Two infusions for rests at 55.5C and 62C and two decoctions for rests at 71C and 76C.  Wort was chilled to 16C out of the CFC and then to 8C in the fridge overnight before it was racked off the trub and break material before the yeast was pitched.

Monday, 27 June 2011

Lager Starters

With a bit of patience and lots of trial-and-error, the new Stir Plates manage to work with the decidedly-not-flat-bottomed 5L glass demi-johns I have.  Luckily I don't need to make such large starters that often, since it was a bit tedious getting it balanced and working and it's not something that I have the patience to do every day.  Here is a 4L German Bock Lager yeast (WLP833) starter that for the Vienna Lager that will be brewed in a few days:

Wednesday, 22 June 2011

DIY Stir Plate Build

Posted this DIY Computer-fan Stir-plate build on both the AHB and JBK forums.  The first stir-plate I built this way has been in use for the last 2 years, and is still going fine, but another one (or two) will be helpful to build large lager starters.
There are many variants and online guides including this epic 6-year-old thread on the AHB forums.

120mm speed-controlled Computer fan, I have used a "Scythe 120mm Blue LED with VR Fan (SY1225SL12VBL)".
12V DC power adapter, (cheap) from Ebay.
8x 8mmx1mm rare-earth magnets, same as the cheapest ones on Ebay when searching for 'rare earth magnets'.
A standard (cylindrical) teflon-coated stir-bar (from lab-supply shop), I find that 20mm and 26mm long ones work well for starters from 50ml to 5L.
An enclosure, screws etc to mount the fan/stir-plate.
Superglue to stick the magnets to the fan-hub.
On/off switch.
Solder, a few bits of wire, gaffer-tape, electrical tape, heat-shrink-stuff.

The good thing about the 'speed controlled' Computer fan is that it comes with its own adjustable speed-control knob, so you don't have to worry about adding that yourself:

The tricky part seems to be getting the magnets positioned correctly.  I use 8 of the 8mm x 1mm round rare-earth magnets, with 2 stacks of 2 on each side of the fan-hub, as you see below.  This size and arrangement seems to work well with the fan, and works with all flat-bottomed stir-containers that I have tried.

Attach the magnets with super-glue, but some care and attention is needed, since they will 'interact' with the copper coils inside the fan and once you have placed one, all the others want to try to stick onto them.  Draw a line across the middle of the fan-hub and then arrange the magnets along that line.  Try to space them evenly since that will help keep the fan balanced (try to do a better job than I did here, also try not to stick your fingers together or to the magnets or fan with the superglue).
The ends of the stir-bar will have opposite magnetic polarity, so each set of 4 magnets (on opposite sides of the fan-hub) must be arranged so that their magnetic polarity is the opposite to the ones on the other side.  Essentially one set of magnets 'push up' and on the other side of the fan-hub the magnets 'pull down', this way the corresponding 'opposite' magnetic attraction from the ends of the stir-bar will 'lock on' to the magnets as the fan spins (even at 1600RPM the stir-bar shown in the picture below will stay firmly attached to the magnets).
(If you placed all the magnets the same way up, one side would repel rather than attract one end of the stir-bar.)

If you buy your stir-bar before you place the magnets, I have found that the best spacing for the magnets is to have them as wide apart as the stir-bar is long (as per the picture below), closer or further apart does not work as well, but the distance is dependent on the length of your stir-bar.
By using 2 sets of magnets, both a smaller and larger stir-bar can be used.

To assemble the stir-plate, cut the plugs from the power-adapter and the fan, and then strip the wires.
Connect the appropriate wires (positive/negative, usually red/black) from the power supply to the fan (red and black wires, the yellow wire is not used, so simply cut it off and ignore it).
The connection will be 12V and only work one way, so you can easily join the wires together to ensure that it works before you attach them permanently.
Solder and shrink wrap are the best way to go, but the wires can simply be wound together by hand and then wrapped with electrical tape.

An on/off switch allows the stir-plate to be controlled without having to pull the plug from the wall, simply wire the power-supply wire(s) to one of the switch's terminal(s), and the fan-wire(s) to the other.
There are many variations of equipment that all work much the same way, you might already have most of the items, and so any additional costs will be minimal.  Any size computer-fan will work, however I find the 120mm fans are easy to work with and the fan-hub is a good size for the size stir-bars that I use.  Most any old computer, or computer power supply will have a fan you can use, simply remove it, strip the wires and use it as outlined above.

(Old) Computer disk-drives have strong magnets inside them that can be removed and glued to the fan-hub, this works fine, but is more effort and since the magnets are a U-type shape with both poles on the same magnet, they are harder to adjust and tend to be a little more uneven.  The rare earth magnets are very cheap on Ebay, so I find them a much better solution.

Any 12V DC power supply should work fine, if you have an old (unused) one from a mobile phone, cordless drill or other electrical device, there would not be any need to buy a new one.  Computer fans also function from about 5V up to about 15V, so in theory any DC adapter in that range will work, however it will change the speed the fan works at, and may make it too fast or too slow.  Old computer power-supplies can also be used, however they tend to be large and cumbersome, but if you have one it is possible to short the on/off leads and use the 12V supply from that to power the stir-plate.  It is also possible to use power-adapters used for external computer-hard drives or the like, since they will usually supply 12V, it is just a matter of identifying which wires are which.

If you do not have a 'speed controlled' fan, you can adjust the speed of the fan by altering the voltage, this can be done with a variable power supply or by changing power supply, however I have found that the continuous-dial-type-speed adjustment works much better than the 'steps' that variable power-supplys offer, and that it is much easier to get the stir-plate working correctly if you can fine-tune the fan-speed.  A potentiometer is also a good way to control the fan-speed, it just requires a little bit of extra electronics.
A search on Ebay for "LED Dimmer" should result in a number of (different types) of LED Dimmers, used for LED lights, these would also make a very good pre-made speed controller for a DIY stir-plate.  Simply wire them in between the power supply and the fan, and they would provide continuous speed-adjustment.

While the teflon stir-bar will not be cheap (for something so small) they are designed for the job and work very well, some people have used various magnetic or metalic items, but especially if you have lab-glassware the additional expense of a real stir-bar is well worth it.  They can also be boiled/sterilized when you make your starters simply by dropping them into the starter-flask while it is on the stove.  The standard cylinder type stir bars work best and are much more quiet than the strange shaped ones or ones with a pivot in the middle, and if you are going to use the stir-plate in your house, keeping it quiet is good. :)

Saturday, 11 June 2011

Brew Day: 10min IPA

This 10 Min IPA will be for the case-swap that is in a few weeks, using this amount of hops is not something I usually do so hopefully it will be an interesting brew.  There have been some comments on the UK JBK forums that suggested I like to use too much brewery-bling (mostly because I've got temp controlled fermentation fridges) so there are lots of pictures today.
10 Min Chinook Greenbelt IPA
Estimated OG: 1.060 SG, Estimated Color: 9.5 SRM, Estimated IBU: 62 IBU
Boil Time: 60 Minutes

Pale Malt (Joe White)    95%
Crystal (Joe White)    5%
0.17g/L    Calcium Chloride
0.43g/L    Calcium Sulphate
10g/L    Chinook '10 (HomeGrown) (10mins)
10.9 billion cells/L  (Repitch)  Wyeast Greenbelt

Single infusion mash @66C.
Brewery at rest

Pre-brew day water filter
(no Chloramines here and Melbourne tap-water is close enough to RO water not to think too hard when creating water-profiles)

95% ale malt, 5% crystal

Malt conditioning (1-2% water, mixed well and left to sit for 15 mins before crushing)

The joy of crushing 6kg malt by hand

The crush

Grain temp & salt additions (Gypsum & dash of calcium chloride)

'Disassembled' mash manifold

19L strike water/preheating mash tun

Strike temp was as expected (but I have no idea what it is reading in that pic)

Not so high tech thermal insulation

Fly sparge/sparge arm

Draining the mash tun

Seems to be no channeling, so in theory that's a good thing

Still waiting for fittings for the 'solar pump' so a bit of lifting required to fill kettle

Hot break removal system

Single hop addition, 230g hops (both packs) @ 10 mins

Hops trying to climb out of the boiler


Pitching temp right out of the CFC

Rinsed yeast, shake jar for 20mins to aerate well

Shake well for a few mins every-now-and-then for an hour-or-so

Cling wrap 'lid' add temp probe and into temp controlled fridge

About 36h later, fridge smells nicely of hops and yeast seems to be happy doing its thing

Recipe adapted from here.
... with more details here.