Melbourne is currently experiencing its hottest run of weather for 100 years or so. For most of this week the temperatures have been peaking between 43 and 45 degrees C (>110 F).

The ice bank I recently bought to use for cooling in the home brewery is essentially a very small refrigerator (20 litres of water/ice mix) with a thermostat that can be set between 0 and 6 degrees C. Being small it is efficient, but it also means that its cooling capacity is less than a domestic refrigerator.

A few weeks ago I found out that the ice bank was able to maintain a cellar temperature of 11 C unless the temperature in the garage got quite warm. I don't remember exactly where the capacity ran out, but I think it was around 30C.

Since then I have been running the cellar at 16C. I'm not trying to make lagers this time of year, and 16 was a nice cool environment to ferment out our recent hefeweizen. This worked very well. Not only is the flavour note on the hefe as good as we have ever made, the ice bank showed no signs of stress maintaining that temperature, and the font flooding pump ran continuously during that time as well.

With the extreme heat this week I've been keeping a close eye on things. We had close on 36 degrees on Tuesday and everything worked well. With the 43 on Wednesday, all was good until late evening. By this time the garage was sitting at an ambient 35 C, with the outside temperature not dropping much all night. At this stage all the ice was melted and the cellar was at 18C and slowly warming. I turned off the font pump and kept the cellar control running overnight. By morning there was still no ice, but the cellar was at 16C, with the garage temperature at 30C.

Thursday the temperature hit 45C outside and 40C inside the garage. During the day the cellar was maintaining 18C - but this was the absolute limit of the ice bank. Friday morning the garage was 30C and with another 43C day it will be a further test of limits. I've adjusted the cellar set point up to 18C to give the ice bank a chance to recover, as there was still no ice this morning. I chose 16C as the lower end for fermenting with Wyeast 1056, and it is good up to 22C. We are now 4 days into ferment so the yeast profile ought be pretty much what we were targeting by now.

Back to the ice bank and its capacity - it looks as though a rough rule of thumb is that it can maintain the cellar at 20 degrees C (around 40F) below ambient. Thankfully our weather in Melbourne is mostly reasonable, so ale temps in the summer and lager temps in the winter will be the norm.

We made Jess' party beer on Monday and pretty much everything went to plan. Our dough-in temps are now regularly spot-on which is really pleasing. The image to the left shows the mash liquor at strike, dough-in, and then 60 minutes at saccarification temps. The small blip on the right of the graph is the circulation of colder liquor - liquor that has been at rest in the external plumbing for 60 minutes. The step to the right is to mash out temperature.

Our main interest was in the wort from kettle to fermenter. We have had two problems - spoilage bacteria lurking in old lines and an inability to chill down to pitching temperatures.

The wort stability test has proven the first problem is solved - as long as we stay vigilant that is. After three days of excessive heat, it is not showing any signs of spoilage. The complete re-work of plumbing and clean processes are no doubt working.

The second one is not so straight-forward. We did a two-step chill of wort before it hit the fermenter. Both steps were done with the plate chiller, the first pass through via tap water for chilling, the second pass through via chilling water pumped from the ice bath.

It did not work as well as hoped. The flow rate from the ice bath was nowhere near enough to provide effective chilling. The wort could only be trickled at the slowest rate to attain our pitching temperature. As a result, only 8 litres of slowly collected fermentable was done this way for the sake of our starter step. The remainder was collected about 5 degrees C high and slowly chilled overnight in the cellar.

I've been thinking about possible solutions. The batch before this we added ice to the hot liquor tun and patched the heat exchange coil into the chilling water path to 'pre-cool' the tap water. This actually worked a whole lot better than the pump solution. I think we might need to re-plumb the system to make this step easy, as all this re-jigging of plumbing during a brew session is getting tiresome. The last session was 7.5 hours long for a standard batch and I was pretty tired by the end of it.

Anyway, the cellar is doing its magic and our blonde ale is promising the goods. We think Jess will be pleased.

Sometimes I need to laugh at myself. I am big on ideas and small on action - too fertile an imagination with poor follow-through. Anyway, in a practical sense it means I'm reluctant to mark and drill a hole in a pristine piece of equipment - in case I change my mind.

I was reminded of this when I began to look closely at kettle modifications (to fix our spoilage bacteria problem). The old kettle outlet had been blocked up in an amateurish way, but the thing that made me smile was how I'd left the old heating element in the urn because I couldn't bear to remove it, just in case ... So it meant the kettle had two heating elements but only one in use, and two outlets but only one in use!

OK, so a few deep breaths, a socket set, and presto - one heater missing and two extra holes in the bottom of the kettle ... And then a few minutes with an angle grinder and the old drain point had been removed.

I had originally intended to use the central port for wort to fermenter. I tried to scrub up the fitting but it didn't look like it was ever going to be hygienic. I thought I might simply block up the old outlet properly by soldering in a plug. But it still seemed a patch on something that wasn't quite right. Ultimately the decision to cut it out was worth it.

The old heating element was mounted in two places in the base of the urn - so removing it left two new ports. I now had to figure out how to deal with three new holes in my aging kettle.

In the meantime, pulling apart bits on the kettle revealed a musty smelling barb fitting on the inner side of the polysulfone bulkhead. Have I mentioned I hate those things? Anyway it is now a primary suspect for our spoilage problems. A critical eye at this point is a good tool. No barbs, no small restrictive openings, and nothing that cannot be part of the clean in place loop. This means that a bulkhead fitting through to a three piece ball valve will all be smooth and capable of flushing with hot PBW. It also means that polysulfone disconnects will make way for camlock fittings. I wish I'd known where to find these things earlier. They are stainless, less restrictive, and cheaper to boot.

After some thinking, I figured the heating element holes could be used as a thermowell (temperature probe) and level sensor respectively. I already had bits  for the thermowell, and for the level sensor I put some fine stainless mesh on the up-side of the fitting with the idea that the sensor will plug the kettle from underneath. Because this is not yet installed, a simple copper plug was screwed into the port. The photo at above right shows the thermowell but also the kettle bottom after a clean in place. The PBW worked wonders on built-up scum. I will have to do a full-kettle clean, it is so effective.

The central drain port was fitted with a bulkhead fitting and plumbed into a three-piece ball valve that is screwed to the side wall of the kettle. With a camlock fitting on the other side, it has the feel of a professional piece of kit.

The clean in place process works well. It looks a little messy with all those hoses - but patching is quite simple. The old machine was much neater but less hygenic. I think I prefer this messy version. Now ... to make some more beer for Jess' birthday.

It has been a long time since I've done a wort stability test. One of my aims this year is to make better beer, and I've had some trouble with spoilage bacteria lately that has seemed to get worse over time. We opened a 6 month old bottle of Dortmunder the other night, and while it was drinkable, it showed symptoms of the problem even then. I wish now I'd been more attentive.

I realised when setting up the brewing rig last Saturday that the $@^@&@ polysulfone quick disconnect bulkhead fitting on the kettle outlet was quite dirty. I gave it as good a clean as I could, and did a solid clean in place with PBW at 70 deg C.

At 2 days into the wort stability test, there was the slightest bit of froth on the top of the wort and it didn't smell as fresh as when we collected it. Three days in confirmed the signature spoilage we've been experiencing. Time to improve our methods ...

The good news is the fermenting beer seems good. It has a little more to ferment out, but the flavour profile is the classic clove hefewiessen which we love. It has been fermented at a steady 17C in the cellar which has been pleasing considering the outside heat. We made sure the starter was healthy, although I'm still not happy with the speed of reaching pitching temperatures.

I had a critical look at the components between the kettle out line through to the fermenter. There are a few things that I'm concerned about. Firstly, the polysulfone bulkhead connector on the kettle is out of the clean in place loop. While the sanitising solution is dropped through it into the fermenters, the lack of cleaning process is an issue. Other things to be concerned about are that there are some taps that remain in place during the last phase that could be eliminated. They are there for convenience, but convenience is no good if they harbour spoilage bacteria.

The final thing that might be an issue - although I'm not sure - is that I have no way of fully drying the chiller and plumbing from kettle to fermenter at the end of the day. I have used a hand pump to pump air through the system, but maybe it needs something a little more. It is hard to tell because I can't see inside all these bits.

Anyway I've devised a simpler flow path from kettle to fermenter and a way of involving all parts in the clean, flush, sanitise, chill, clean, flush, dry process. It does mean that some manual patching is necessary, and I'll need to buy some better fittings. In particular doing away with the polysulfone fitting will be satisfying. I've had nothing but trouble with them even though they seemed like a good idea.

The kettle (an old 50 litre stainless steel urn) had an outlet in the middle bottom that I blocked up a long time ago. The current outlet is in the wall of the urn via a polysulfone bulkhead with stopper. With some re-plumbing, the original drain point can be used again. This means the polysulfone connector can then be used as an overflow for cleaning.

To clean these parts in place, I intend to put a PBW solution in the hot liquor tun. This then gets pumped via a camlock disconnect (yet to be installed) into the fermenter line which is patched in for the cleaning cycle. Hot PBW gets pumped up through both chillers and a three-piece ball valve into the bottom kettle outlet. When the kettle reaches a sufficient level, a line from the existing polysulfone connector will drain excess cleaning solution back into the hot liquor tun. This way the cleaner can cycle in a closed loop.

The same process can be used to circulate flushing water or sanitising solution. This way it involves all critical post-boil parts in the cleaning and sanitising process, hopefully realising the aim to make better beer this year.

The summer has arrived late this year, but we've been having a run of hot days of 100 or more degrees F. When I was a kid at school we still use Farenheit in Australia, and 100 was the mark when we could go home from school.

Anyway, with the heat comes all sorts of challenges in a home brewery, and one of them is getting wort from boiling down to pitchable yeast temperatures. The brewing rig before our current one had a large copper counter-flow chiller. This worked well but took up a lot of space. It was capable of getting wort down to within 1-2 degrees of the cooling water. For the sake of a compact design, we bought a plate chiller to use in the current brew rig. I miss the old unit though, because it was so much more effective. The plate chiller does ok for its size, but it is only capable of getting wort down to within about 10 degrees of the cooling water. At this time of year that makes a significant difference.

Because we like making lagers, it is still an issue for us, even in the depths of winter. A chat with the brewer in a local brewpub revealed an interesting idea that I'm inclined to implement in the home brewery, now that the ice bank is up and running.

What they do at Two Brothers is a two-stage cool of the wort. They have two plate chillers, the first one is run from the domestic water supply, the second from their glycol plant. I did some guestimates today and it makes sense. If the tap water is 20C, the best you can hope for with an efficient cooler is wort that exceeds most ale pitching temps. They make lagers as well, so a second run through with glycol will probably give them any temperature they desire from 0 degrees upwards. Even the coldest of lager pitches is only likely to be about 8 degrees C.

When I bought my ice bank, there were some specs that suggested how much cooling capacity was available before all the ice had melted. They are designed to be a peak demand unit, and can supply 66 litres of cooling for beer stored at 16C; 40 litres of cooling for beer stored at 24C; 29 litres of cooling for beer stored at 32C.

By these figures, I worked out that if I can do a cooling stage from the domestic water stage that will drop wort to 28C (which is feasible even at this time of year), then I can flash chill in stage two using the cooling water from the ice bank, and end up with 42 litres of wort at 10 C, ideal for lager pitching. As I don't intend to make lagers during the peak of summer, there should be more leeway than this.

So I had a look at the old counter-flow chiller. Apart from it being a ridiculously expensive lump of copper, it seemed a shame to see it lying about in the parts bin. On the new rig, space is not the issue it once was, so I figure that this will be ideal for stage one cooling, with the existing plate chiller for stage two.

I now have a bit of work ahead of me to sort this all out, but is seems like a good solution to something that has nagged me for a long time.

When the HERMAN project was first conceived nearly a decade ago, the main idea was to create a machine that would free up time so that I could keep brewing all-grain beers despite the time pressures of my work.

As the machine became reality, it was a delight to have mash temperatures and steps automated, and even have hops drop into the brew kettle on cue without human intervention. As we have gotten use to this technology, we have used some of the in-between bits of time to do things like catch up on housework, take the dogs out to the local sports ground, and take a lunch break at our favourite local creek.

I've long dreamed of being able to check in on HERMAN via mobile phone or an internet connection. We are now getting closer to fulfilling that dream.

A few months ago I upgraded my PDA because the old one was no longer working. I use it mainly as a portable diary that syncs with my office computer. While looking around at the various models, I decided one that had inbuilt wireless would be useful for connecting into the home wireless network. These PDAs are powerful computers in their own right, and so I did a little playing around in December with Visual Studio 2005 coding simple programs and interfaces on the PDA. With a colour 320x240 pixel screen, touch sensitive control of the screen and wireless, it seems there is a lot of potential to press the device into the service of making beer.

I'm just dreaming now, but I can envisage a control panel on the PDA that has a wireless connection (locally and via internet) to the machine. It is a project that is for doing just because I can, and so really has no pressing timelines.

It was this dreaming that prompted me to give the arduino a go. I've had my eye on the 'Making things talk' book for some time now, and the online preview suggested it was the exact missing link that would help me patch all these bits together and brew via remote control.

I can just imagine it now ... HERMAN V 2011 informing me that the boil addition has just happened successfully while I am down the street at a local cafe sipping a flat white.

I'm not really one for New Year's resolutions, but an overview of directions for the coming year seems in order.

• make better beer

I am guilty of not giving enough attention to detail at times and when making beer this can become a problem. Occasionally it has been something relatively minor like not paying attention to water chemistry. In this regard probably the biggest disappointment was the Dortmunder export lager that was simply too sweet because we had not adjusted the water.

The area that has hit us worst though is sanitation. Our plastic fermenters are getting old and it seems they are harbouring more bacteria than they once did. A change recently to a better sanitiser has made a difference, but I've never really liked using plastic. In the big picture of the brewery, it is a weak link. We have recently bought up a couple of stainless steel LPG tanks. Surprisingly they are cheaper than new plastic containers and ought to do the job well. Our first project plan for the year is to cut the top off one and fit it out for a fermenter. Being all stainless it ought to clean up and be a reliable food grade container.

The final part of this picture is improved temperature regulation. The old fridges that we recently walked out the door were great bug factories - and my cleaning practices were not the best (attention to detail again). We are now able to ferment in the cellar box (effectively a larger automated 'son of fermentation chiller'). We also plan to install a cooling coil inside our new stainless fermenters to regulate temperatures without putting the tank inside the cellar.

• make brewing easier

This one is of particular importance to Leah who is unable to lift and clean many brewery items. We need to work smarter, not harder so that she can still brew. The current HERMAN machine brews 40-42 litre batches. The vessels are lightweight stainless steel urns coupled with an igloo insulated drinks container (38 litres). Even though these are all much lighter than the usual kegs, they remain too heavy for Leah. I also have an interest in minimising lifting and awkward cleaning jobs because of an ongoing back complaint.

The plans are well under way for a 'clean in place machine' based on converted LPG tanks. We intend to have tippable vessels which can be sprayed and wiped in place. Lines and taps will be cleaned chemically, again 'in place'. Brewing has already moved from the laundry down into the garage because there is more space there and it is a better 'wet' area.

I have a terrible tendency to make things too complex, so I'm excited about a number of design features that will simplify the new machine. More on that later ...

• be open to new things rather than comfortable with 'I've always done it this way'

I realised recently that I've tried to push the limits of picaxe processors. That is not a bad thing in itself, but when it comes to creating a moderately complex machine (like HERMAN) that demands a level of automation and a decent user interface, it is not always good to be blinkered. I've just ordered an arduino duemilanove with an ethernet shield, plus the 'Making things talk' book. The arduino promises to do many things better than a picaxe - menu systems, floating point maths, PID, keeping track of time, no issues with serial comms hanging etc.

I don't plan to supercede picaxes - they are simple to program and cheap to buy. I won't be buying lots of arduinos, but I do have plenty of picaxes in my parts bin. Really it is about using the right tool for the right job - and about getting over my phobia of C type languages.

• this week and next

Of immediate interest to us is kitting out an LPG tank as a fermenter. We will install a cooling coil (from copper pipe) inside so that it can be regulated with cold water from the ice bank. We will get a 3 piece stainless valve for the drain tap, and also install a port on the bottom as a 'pseudo-conical' yeast collection point. This may or may not be effective, but in any case this vessel is to be dual purpose - both Hot Liquor Tun and fermenter. The details of that will follow in another blog entry.

The other thing to do is to plumb in a water line so we can brew in the garage, and wire in a 15A circuit as well. By this time we will be busting to brew some beer because our 50 patrons since New Year's Eve have just about quaffed our entire stock.

I've now had a few weeks to assess the performance of the cellar and bar. The cellar is an insulated box (old freezer) with a PC radiator and fan used to blow cold air into the cavity. A temperature controller switches a pump and fan combination when the cellar warms above the setpoint. The ice water that is pumped through the radiator comes from the ice bank.

The ice bank builds up ice around the edges of its' water container as means of creating an ice bank that can be melted during periods of high demand. I accidentally created a high demand incident over the last few days because I plugged the radiator fan & pump into the wrong controller output. This meant that they ran continually, eventually melting the ice bank completely. I had wondered why the cellar temperature had dropped to 7-8 deg C. The ambient temperature was 25 degrees, so on a really hot day it might max out the ice bank if I'm trying to keep the cellar at a cool 11C.

The photo above shows the cellar is at 13C and the ambient temperature is around 18C (the two controllers at left).

At all other times the ice bank has not shown any signs of melting under load. The font can be flooded with cold water continuously and the cellar radiator can be working and we can pour beer and flash chill from cellar to serving temperature - all without putting too much strain on the system. I'm sure I can add a fermenter cooling coil to that without too many dramas.

There are some improvements to do yet. I need to install lighting inside the cellar so I can inspect kegs and check for condensation. I need to install collectors for condensation. At the moment I suspect there is condensation where the cold air blows into the cavity, and there is significant condensation on hoses to the flooded font connection.

I am pretty certain that this system could also be run with a standard chest freezer providing the cooling plant in place of the ice bank. I had a good freezer for a short time before the ice bank arrived. With it I was able to chill a 12 litre container of glycol to below zero from about 25C in just a couple of hours. The tricky issue would be how to prevent things outside the glycol from freezing as the glycol will most often be warmer than its surrounds. I went with the ice bank to eliminate that engineering challenge.

... and the really satisfying thing was that for both the New Year's Eve party and Leah's party a couple of days later, we had people hang about in the garage around the bar which has never happened before.

December is my busiest month - which has been frustrating because I'd put the pieces together for a working bar for our New Year's Eve party, only to run into problem after problem.

In the last entry I mentioned the ongoing saga of freezers. I finally found a freezer that was good, but just as I'd committed to buy it on ebay I found an ice bank available for what seemed a reasonable price. Thanks to support from Ani, I couldn't help but buy it.

The ice bank arrived a week before Christmas, and it took a while to find the time to connect everything up. When it seemed that all was good, I discovered that one of the beer coils had a leak in it! The supplier was quick to respond, but I then had trouble with the freighting company and the replacement did not arrive until after New Year .

Anyway, the New Year's Eve party was a hit. The bar had beer flowing from one of the three fonts and all the planning and construction was worth it.

The ice bank itself is tiny. It stands about half a metre tall which means it is ideal for sitting under the counter of the next piece I'll be adding to the bar. The three fridges (fermenting - lagering - serving) have now walked out the door, along with all the freezers I've been collecting over the last month. This has helped clean up the garage a lot, which means the bar now has space in the corner.