HERMAN

I've had mixed results recently working on HERMAN. Last week I began the process of re-plumbing the solenoid valves to tweak machine performance. This included having two water in valves (one dedicated to the mash tun and one dedicated to the HLT) after I found that reverse pressure would open them. The other change was brought about by installing the immersion chiller with agitator in the kettle. This meant I no longer needed to circulate kettle wort through a chiller until it reached pitching temperature. A side effect of this was that there was only one wort path out of the kettle (into the fermenter) compared to two previously.

I had to pull apart the valve that was part of the old kettle wort chilling loop and discovered a good deal of hop debris in it. I think it was a good move to eliminate this path. Now the chilled and settled kettle wort simply gets dropped via gravity into a fermenter. The valve and fermenter fill path will be sanitised at the start of brewing with Starsan or equivalent.

Through various plumbing changes I had a significant amount of trapped liquor. Revising the solenoid arrangement gave me the opportunity to add a low point valve (manually operated ball valve) for drainage. The changes also meant that the solenoids needed re-wiring.

All that seemed to progress quite well until it was time to connect everything up and test. The manual switches did not engage the relays and after about 15 seconds puzzling I noticed that a ribbon cable connecting the BrewTroller controls to the relay card was melting! I have no idea yet what was happening but this is one of the drawbacks of creating a complex vero-strip interface. I noticed one cable was not plugged in, but not sure why that would make a difference. At least the BrewTroller seems to be fully functional so that is a blessing. I'm eager to get a version 3 board with 16 outputs (assuming that will be the final arrangement) so that I can settle on some final interface designs and etch decent relay boards.

So at the moment I have a pretty looking set of solenoids that are not working.

Beyond that there were numerous small tweaks. This included improved plumbing between solenoids and tuns and changing the depth of the kettle temperature probe so that it is higher in the tun than the heating element. The idea is that when hot wort from the mash hits the probe, the BrewTroller can automatically apply kettle heating because the element will be covered. The BrewTroller control box was finally mounted properly with suitable placement of cables and space for the laptop to sit if so desired. I think pretty much every time I brew I will have the laptop running with BTremote just for the convenience of it.

I've managed to stockpile enough beer to last me through a longer phase of BT improvements so I'm in no hurry but rather wanting to apply good solutions rather than temporary ones. Assuming the relay interface board is actually ok, I think I will brew in two or three weeks. I'm aiming for a nice tasty American Pale Ale.

Beyond physical construction work, work has continued on the BTremote program. There have been a lot of tweaks communicating between BT and the PC and I'm nearly ready to release an update where recipes can be done reliably on the PC and downloaded to the BT. This means no more painful tweaking of the rotary encoder to add recipe names and set parameters. It is a great input option for a stand-alone device, but so much easier if you don't need to use the encoder for detailed input like setting up a recipe. My APA recipe was uploaded from the PC to the BrewTroller without even a tweak of the encoder, so a big step forward there.

It always seems like there are way too many projects to work on in the home brewery.

I'd love to have built that counter-pressure bottle filler and I have the parts to do it but ...

And I still haven't finished my LPG tank conversion into a stainless fermenter, nor have I sorted out the conical shell I have for another fermenter...

And I've now done enough on the bar to allow myself to be distracted by other things ...

There are many loose ends on the BrewTroller sculpture that need sorting out. The solenoid valves need a bit of work so that I can effectively fill both mash tun and hot liquor tun and also provide a system drain point for storage, so liquor does not stay in pipes and stale.

I continue to have problems with the BrewTroller dropping out with back emf spikes from the solenoid switching. I'd really like to sort this out so that I can concentrate on brewing rather than getting back to a restore point on the BT. There are at least two things to do here - put some filter capacitors on the rotary encoder switch, and put in some filtering on the one-wire bus.

Then the pressure sensors need some attention. I suspect I am getting some pressure leaking but I also need to add some filter capacitors to the sensor. I'd then like to do some solid testing of temperatures and levels so that we can improve the level readings for the BT community.

But right now I'm not even doing work on the sculpture but rather I'm engrossed in coding for BTremote. Now that the program can load data from a ProMash file, it is close to getting recipe data uploaded to the BT without the need to use the rotary encoder for data entry. Being able to do this will be satisfying personally but will also probably please a lot of other BT users. And then after that it will be adding support for BeerSmith, and then enabling more robust control of the BT via BTremote and eventually the web.

The source code and latest build versions of BTremote are available at Google code and the wiki and forum at brewtroller.com are also a great source of information.

So many things and so little time ...

I've not had much time of late to work on brewing things but the last week I've begun to develop phase II of the bar and cellar.

Phase I was an insulated box with my three tap flooded font mounted on it. It was primarily a fermenting chamber although during the summer it was needed to house the serving kegs. The cooling unit was external as was the gas bottle. The gas manifold for serving kegs was mounted inside the chamber which was less than ideal. Also the condensation from the flooded font meant the inside was always quite damp.

The fermenting chamber maintains temperatures well. In effect it is a fancy 'son of fermentation' chiller. There is no need to change out ice bottles as the cooling comes from the ice bank. I pump ice water through a PC cooling radiator which then blows cold air into the chamber.

I've been wanting to have two parts to this arrangement for a while. The opportunity to make a bar and have the existing chamber solely for fermenting and conditioning came when Leah's brew sculpture was given back to me. A while ago she decided she couldn't brew on her own, so after some negotiating I ended up with a solid base for a new bar.

One of the main condensation problems with the old arrangement came from the flooded font. With the new bar the font is directly above the ice bank which means the condensation ends back into the ice water reservoir. I've now got this part on the bar running well. The next issue I needed to resolve was getting the cellar temperature right for serving English Ales through my beer engine. I didn't want to use the fermentation chamber for this because I would again have issues about gas lines and manifold access. Additionally, last summer I needed to keep the kegs in a temperature controlled environment when the summer was at its hottest. The mercury hit 48C here in January! The new bar allows enough room for serving kegs and gas bottle and creating a mini cool room around the kegs. This means I can run it like an English pub cellar and also keep the beer engine cool at the same time.

The beer engine is designed to sit on the serving side of a bar and so it needed a bit of dressing up to look nice. It took a bit of cutting and adjusting but I now have the engine mounted in a box like structure that I'm happy with. A lift up flap on the bar top gives access to the gas manifold, keg tops and gas bottle. Front doors will allow access to the ice bank on one side and kegs and gas bottle on the other.

Beyond that I will have some shelving to hold beer glasses and trophies. The glass storage might have to stay on the fermentation chamber.

It has been a nice break from building the BrewTroller machine but soon I will get back into that project. It will be nice to test the bar and fermenation chamber during the coming summer. It is already warming up here in Melbourne so lager season is nearly over.

I brewed a lager today that is a cross between a Helles and a Czech pils. It's a recipe that was inspired a long time ago by a lunar eclipse so I've given it the name Eclipse. The recipe tweak this time around is to use Summer Saaz hops which are a new breed coming out of my home state of Tasmania. They don't have the spiciness of Saaz and have a touch of the grapefruit flavours, but other than that they are similar to Saaz according to the description.

I haven't had any time to do improvements on the machine except that I'm running build #263 on the BrewTroller and Matt has coded in some of my asked for features. This time around the HLT temp is based on the Mash target plus a differential. Also the kettle power can be controlled on the fly now to get that perfect rolling boil.

Probably the most significant thing is that I had a moment of insight while looking at a graph of my last brewday. I've had troubles with mash temperatures oscillating nearly a full degree C. I've not been happy with that and the average temperature has been nearly half a degree low. While it is not devastating to brewing, it had puzzled me.

What I realised is that my dough-in mixer wets the grain well but it leaves hotter liquor at the top of the tun compared to lower down where the bulk of the grain is. With HERMAN 6, if I hit target the pump would simply turn off and it meant that this layering of temperatures stayed that way without me realising it. Now that HERMAN 7 has a heat bypass switch I have been recirculating for the entire mash and wondering why I was missing my target by a couple of degrees on the low side.

It also explains why I've needed to 'fudge' my strike liquor calculations. I've aimed a couple of degrees lower than the ProMash calculator for years, and to do that with the BrewTroller I've used a ridiculously high grain temperature.

So it turns out that my temperature probe sits at a high point in terms of mash liquor temperature. It also explains why my beers have tended to be on the dry side (which hasn't been an issue because that's my personal preference).

So with this as a theory, I've trusted the calculators today and what do you know ... the mash settled spot on the target of 66 degrees C. Getting this bit right and having the HLT track the mash target has meant that I've not only hit target, but the mash has stayed on target for the whole hour. I don't think it has ever been as finely tuned as today where my variation around target was +- 0.1 degree C. (Ignore the dodgy time scale - I've got some recoding to do there).

The wort chilling seemed to take a long time but it was okay because I'm not in a hurry while making beer. I chilled the kettle wort to 20C with ground water and then dropped to 8C via the ice bank water and pump. That all worked okay.

There are still lots of rough edges that need attention, but this was a very successful brew day. I've now got plenty of beer in the cellar which means that in the near future I can make those improvements I've been dreaming of.

I've been listening to Brew Strong lately and again Jamil and friends have helped improve my brewing. In particular I listened to their yeast starter program and have just pitched the healthiest yeast starter for a lager ever.

The starter was for a Dortmunder lager which was batch #3 on the new HERMAN 7 powered by BrewTroller.

I've blogged about a number of things on the BT site about this brew, but some observations for my own reference:

• To chill to lager pitching temps, I need to use ground water initially and then do the last stage (maybe below 30C) with ice water.
• What I actually did to chill was use the plate chiller with ground water and pumping ice water through it to pre-chill the ground water. It chilled everything a lot quicker than normal, but most of my ice water was depleted too soon. I had to wait a while for the ice bank to restore to get to lager temps and had to pump ice water directly through the immersion chiller to do it.
• Use a hop sack in the boil kettle to minimise hop debris and therefore trub dumping into the fermenters.
• Improve the filter at the kettle pickup to fermenter.
• Wire in the fermenter fill solenoid and remove the kettle pickup solenoid.
• Put a meter on the mash level sensor to figure out what is going on between mash fill and mash empty and record notes.
• Get some air bleed valves so that the March pump primes reliably.
• add a low point drain on the system so it will clear all trapped water.
• Use the retrieved solenoid from kettle pickup to be the mash liquor in solenoid.

All up I was happy with how the brew day went. There is still a lot of debugging to do on the BrewTroller and hardware but it is a joy to use HERMAN 7 and is by far the best HERMAN yet.