Second Sourdough

Same formula as last time, except with 70g rye flour substituted for 70g plain flour, and 1 1/2 tsp caraway seeds added.  Instead of splitting in two, cooked as one larger loaf.second-sourdough

The size is better for this pot. The final rise before baking went more sideways than I wanted, and trying to control that with tea towel wasn’t a great idea.

Anyway, the important thing is that it’s super yummy.

Unlike my infrequent homebrewing, I don’t expect I’ll blog every bread I bake.  Unless I learn something that’s good to remember.

First Sourdough

(They say “Beer is liquid bread”, so I’ve put this bread-making post in my “Homebrew” category.)first-sourdough

Dad had been making bread in Queensland when we visited over the holidays, and I thought I would have a go in my final week of holidays back in Sydney.  Basically a sourdough, but with yeast added too, to moderate the sourness.

First, I made a sourdough starter, over 3 days:

  1. 100g rye flour + 100g homebrand plain flour (10.9% protein) + tablespoon honey + 200mL water
  2. Half of Day 1 + 100g plain flour + 100 mL water
  3. Half of Day 1 + 100g plain flour + 100 mL water

Then, a sourdough recipe adapted from “The Bread Baker’s Apprentice“, over two days:

  1. Half of the starter above (the other half goes to the fridge for future use) + 100g flour + under 1/4 cup water – combine and rise for 4 hours, then into fridge overnight
  2. Remove from fridge cut into 10 pieces, leave in oiled bowl, covered by cling-film
  3. Combine with 570g flour + 1 cup water + 1 1/2 tsp. dried yeast (revived in 1/2 cup water + tsp sugar) + 2 tsp salt
  4. Knead for 15 minutes on flour dusted surface.  Got window-pane
  5. Shape to ball, leave to rise for 90 min in oiled bowl covered by cling-film
  6. Split into two (one portion into the freezer for a later date), shape into batard for an oval Le Creuset pot
  7. Leave rise for 60 min
  8. Preheat oven to 270C, with empty Le Creuset pot and empty baking dish
  9. Put scored batard into pot into oven, add boiling water to baking dish for steam
  10. Spray oven walls with water every 30s a few times
  11. Reduce heat to 250C, for 30 minutes

Evaluation: Not browned properly – I baked longer than I probably should have (recipe said 20-30 min), waiting for the loaf to brown, which didn’t happen.  Not really high-risen, but that might be because of how I shaped it.  Crumb is OK, but less character than I might have hoped for.  Nice enough flavour – not too sour, though not hugely complex, either.

Trouble-shooting: I removed the baking dish/water tray only after 20 mins baking – maybe it should have come out earlier? I’ll try that next time.  My flour is general purpose, not baker’s flour, but I’m going to see how far I can go before changing that.  The yeast was old (2 years past expiry date, and kept in the cupboard not the fridge!), and initially slow to activate in the water + sugar, but looked fine when it got going after 10 minutes or so.

(Or, maybe try the French Oven Bread recipe?  Or the Pain à L’Ancienne recipe?  So many options, so little time…)

Coopers IPA

First homebrew for two years.  Coopers IPA + “Country Brewer Ultrabew” (500g Light Malt, 250g Dextrose, 250g Maltodextrin) + 12g Citra finishing hops.  Still just brewing from a kit, but it’s the first time I’ve added hops.

Back at NICTA, and a few Reflections on Medical Device Engineering

In February I moved back to NICTA after what proved to be an interesting sabbatical year working at Saluda Medical.  Saluda is going strong – they have great technology, and very recently closed a $10Mill VC round which will lead towards major clinical trials of their implanted spinal cord stimulator in the US.

I learned a lot working at Saluda, which is always fun – I hadn’t previously worked alongside mechanical engineers on product design, nor alongside electrical engineers doing signal processing, nor thought much about manufacturing process and product validation for manufactured devices. My role included work defining user requirements, system specifications, system architecture, system validation, and system verification. But perhaps the most interesting thing was risk management, which is central to systems engineering and is highly interdisciplinary. The system I was involved with is now undergoing clinical trial in the US. I also contributed to my first (very cool) patent application, and helped co-author a (conference) publication on placement of paddle leads for spinal cord stimulation. There is perhaps another (journal) publication in the works on adverse events for spinal cord stimulation. And I had the opportunity to learn Python, which was fun, and to learn more about Microsoft Word Interop scripting than I ever wanted to know.

The medical device industry has an interesting regulatory environment.  Of course it’s very conscious about risks and ethics. However, there is a surprising amount of flexibility about how companies can choose to engineer medical devices. Nonetheless, when a company has said how they’ll demonstrate safety and/or effectiveness (and having had that plan approved), regulatory monitoring and review is a powerful way of making sure that happens. That’s especially pointed when companies are selling medical devices (which Saluda hasn’t yet started to do).

More Philosophy of Engineering

In January, the the journal Synthese accepted and published the first of two papers of mine on the philosophy of engineering.  The second installment is now also accepted and published: “Critical rationalism and engineering: methodology” (author’s preprint here). Woot!  In the new paper I use the three worlds schema from the first paper to look at possible sources and responses to falsification of engineering theories.  I also discuss the growth of knowledge in engineering.  Finally, I talk about assurance in engineering.  There are perhaps more open questions than answers, but the questions are important and interesting.

Assurance is key for engineering.  Engineers design and create artefacts that other people use.  But engineers don’t just throw artefacts “over the wall” (or into the market) – they also warrant that those artefacts can be used to meet people’s needs. Those assurances don’t just get made up.  They are backed by explicit justifications – arguments using empirically-validated engineering theories.  For safety-critical systems, if those arguments are invalid or those theories are false, people will die or get hurt.  That’s why it’s worth understanding engineering epistemology.


Moving to Saluda Medical

Today I’m starting in a new role as Systems Engineering team lead at Saluda Medical – a medical device startup company. We’re working on a new technology for closed loop control for spinal cord stimulation that will target the treatment of Chronic Neuropathic Pain.  This is a great group of people and a technology with huge potential.  Saluda Medical is a spin-out from NICTA, where I’ve been working for the past ten years.  I wasn’t part of the Implant Systems team before they spun out, but I was cheering loudly from the side-lines, so I’m very excited to be part of the team now.

NICTA’s been a fantastic place to do world-leading research, and to think about how that can lead to international impact and ultimately benefit Australia.  I’m happy I’ll still retain an association with NICTA – mostly to help close out some PhD student supervision but also to finish off a few pieces of research collaboration.

It’s sort of ironic that the very week my first philosophy of engineering paper was published was the same week I started the move back to industry!  But it’s all about engineering.

Philosophy of Engineering

What is engineering? Sometimes people think engineering is just the same as science, but in a new paper on the philosophy of engineering (preprint here), I argue why that’s not the case. Engineering is similar, but different to Science, and its epistemological issues are also similar but different.

I got into this question because of problems in assurance for software engineering and formal methods that are essentially philosophical problems. But having work available on the philosophy of engineering available should also help with perennial questions like “Is Software Engineering a field of engineering?” and “Is Computer Science a science?”.

Heritage Lager Again

Wow – more than a year between homebrews, again. I’ve almost depleted my stores, which gives you some idea of how much I’ve been drinking and socialising over the past couple of years (not much of either). I find old homebrew basically gets better with age, but maybe I’m pushing it with some of the 2 year-old beer. Anyway, again (but not by design) I’m doing a Cooper’s Heritage Lager, but this time with a Cooper’s Light Malt tin as the adjunct. O.G. is around 1.042.

Heritage Lager

Almost a whole year since my last brew (which has worked out great, BTW).  Inspired by a colleague’s homebrew at Friday afternoon drinks, I’ve dragged a kit off the shelf to start another brew.  This time it’s a Cooper’s Heritage Lager, with 600g Dextrose and 400g Maltodextrin.  Nothing fancy.  O.G. is somewhere around 1.042 to 1.044.

What Software Engineers Should Know

Software Engineering would be a more mature discipline if we had spent more time reading What Engineers Know and How They Know It: Analytical Studies from Aeronautical History rather than A Pattern Language: Towns, Buildings, Construction.