Traveling through mainland Europe on a British passport leads you to several predictable conversations. There’s Marmite of course, then all the fun of the Brexit fair, and finally on a more serious note, beer. You see, I didn’t know this, but after decades of quaffing fine ales, I’m told we do it wrong because we drink our beer warm. “Warm?”, I say, thinking of a cooling glass of my local Old Hooky which is anything but warm when served in an Oxfordshire village pub, to receive the reply that they drink their beers cold. A bit of international deciphering later it emerges that “warm” is what I’d refer to as “cold”, or in fact “room temperature”, while “cold” in their parlance means “refrigerated”, or as I’d say it: “Too cold to taste anything”. Mild humour aside there’s clearly something afoot, so it’s time to get to the bottom of all this. Continue reading “Why Do Brits Drink Warm Beer?”
This particular story on researchers successfully making yeast-free pizza dough has been making the rounds. As usual with stories written from a scientific angle, it’s worth digging into the details for some interesting bits. We took a look at the actual research paper and there are a few curious details worth sharing. Turns out that this isn’t the first method for yeast-free baking that has been developed, but it is the first method to combine leavening and baking together for a result on par with traditional bread-making processes.
Basically, a dough consisting of water, flour, and salt go into a hot autoclave (the header image shows a piece of dough as seen through the viewing window.) The autoclave pressurizes, forcing gasses into the dough in a process similar to carbonating beverages. Pressure is then released in a controlled fashion while the dough bakes and solidifies, and careful tuning of this process is what controls how the bread turns out.
With the right heat and pressure curve, researchers created a pizza whose crust was not only pleasing and tasty, but with a quality comparable to traditional methods.
How this idea came about is interesting in itself. One of the researchers developed a new method for thermosetting polyurethane, and realized that bread and polyurethane have something in common: they both require a foaming (proofing in the case of bread) and curing (baking in the case of bread) process. Performing the two processes concurrently with the correct balance yields the best product: optimized thermal insulation in the case of polyurethane, and a tasty and texturally-pleasing result in the case of pizza dough. After that, it was just a matter of experimentation to find the right balance.
When you’ve got a diabetic in your life, there are few moments in any day that are free from thoughts about insulin. Insulin is literally the first coherent thought I have every morning, when I check my daughter’s blood glucose level while she’s still asleep, and the last thought as I turn out the lights, making sure she has enough in her insulin pump to get through the night. And in between, with the constant need to calculate dosing, adjust levels, add corrections for an unexpected snack, or just looking in the fridge and counting up the number of backup vials we have on hand, insulin is a frequent if often unwanted intruder on my thoughts.
And now, as my daughter gets older and seeks like any teenager to become more independent, new thoughts about insulin have started to crop up. Insulin is expensive, and while we have excellent insurance, that can always change in a heartbeat. But even if it does, the insulin must flow — she has no choice in the matter. And so I thought it would be instructional to take a look at how insulin is made on a commercial scale, in the context of a growing movement of biohackers who are looking to build a more distributed system of insulin production. Their goal is to make insulin affordable, and with a vested interest, I want to know if they’ve got any chance of making that goal a reality.
Companies spend thousands developing a project for the market, hoping their investment will return big. Investing like this happens every day and won’t shock anyone. What may surprise you is someone who spends more than a decade and thousands of their own dollars to make an open-source version of a highly-marketable product. In this case, we’re talking about genetically modified yeast that produces spider silk. If that sounds like a lead-in to some Spiderman jokes and sci-fi references, you are correct on both accounts. [Justin Atkin] had some geneticist work under his belt when he started, so he planned to follow familiar procedures like extracting black widow DNA, isolating and copying the silk genes, and pasting them into a yeast strain. Easy peasy, right? Naturally, good science doesn’t happen overnight.
There are a few contenders for the strongest spider silk among which the golden silk orb-weaver gets the most attention, but the black widow’s webbing is nearly as strong, and [Justin] is happy to wear black widow inspired bling, whereas the golden orb-weaver looks like it crawled out of Starship Troopers. His first attempt to extract DNA starts with a vial of preserved
nightmare fuel spider specimens because that is a thing you can just go online and buy. Sadly, they were candied in alcohol, and that obliterates DNA, so he moved to dried specimens from breeders, which also failed to produce results, and those were just the landmark hangups.
In the recent frenzy of stocking up with provisions as the populace prepare for their COVID-19 lockdown, there have been some widely-publicised examples of products that have become scarce commodities. Toilet paper, pasta, rice, tinned vegetables, and long-life milk are the ones that come to mind, but there’s another one that’s a little unexpected.
As everyone dusts off the breadmaker that’s lain unused for years since that time a loaf came out like a housebrick, or contemplates three months without beer and rediscovers their inner home brewer, it seems yeast can’t be had for love nor money. No matter, because the world is full of yeasts and thus social media is full of guides for capturing your own from dried fruit, or from the natural environment. A few days tending a pot of flour and water, taking away bacterial cultures and nurturing the one you want, and you can defy the shortage and have as much yeast as you need.
Trent Fehl is an engineer who has worked for such illustrious outfits as SpaceX and Waymo. When he got into baking, he brought those engineering skills home to solve a classic problem in the kitchen: keeping a sourdough starter within the ideal, somewhat oppressive range of acceptable temperatures needed for successful fermentation.
A sourdough starter is a wad of wild yeasts that you make yourself using flour, water, and patience. It’s good for a lot more than just sourdough bread — you can scoop some out of the jar and use it to make pancakes, waffles, pretzels, and a host of other bread-y delights. A starter is a living thing, a container full of fermentation that eats flour and has specific temperature needs. Opinions differ a bit, but the acceptable temperature range for active growth is about 60 F to 82 F. Too cold, and the starter will go dormant, though it can be revived with a little love. But if the starter gets too hot, all the yeasts and bacteria will die.
While there are of course commercial products out there that attempt to solve this problem of temperature control, most of them seem to be aimed at people who live in some wonderland that never gets warmer than 80F. Most of these devices can’t cool, they only provide heat. But what if you live in a place with seasons where the climate ranges from hot and humid to cold and dry?
The answer lies within Chamber, a temperature-regulated haven Trent created that lets these wild yeasts grow and thrive. It uses a Peltier unit to heat and cool the box as needed to keep the mixture fermenting at 26°C /78.8°F.
Thanks to the Peltier unit, Trent can change the temperature inside the chamber simply by alternating the direction of current flow through the Peltier. He’s doing this with an H-bridge module driven by a Raspberry Pi Zero. When it starts to get too warm in the chamber, the fan on the outside wall vents the heat away. A second fan inside the chamber pulls warm air in when it gets too cold.
Trent says that Chamber performs really well, and he’s recorded temperatures as low as 60F and as high as 82F. He mostly uses it for sourdough, but it could work for other temperature-sensitive food sciences like pickling, growing mushrooms, or making yogurt. We think it could be ideal for fermenting kombucha, too.
Chamber works well enough that Trent has put further development on the back burner while he makes use of it. He does have several ideas for improvements, so if you want to help, check out his website and Github repo.
Join us on Wednesday at noon Pacific time for the open-source biology and biohacking Hack Chat!
Justin Atkin‘s name might not ring a bell, but you’ve probably seen his popular YouTube channel The Thought Emporium, devoted to regular doses of open source science. Justin’s interests span a wide range, literally from the heavens above to the microscopic world.
His current interest is to genetically modify yeast to produce spider silk, and to perhaps even use the yeast for brewing beer. He and the Thought Emporium team have been busy building out a complete DIY biology lab to support the effort, and have been conducting a variety of test experiments along the way.
Please join us for this Hack Chat, in which we’ll cover:
- The how’s and why’s of yeast genetic engineering;
- What it takes to set up an effective biology lab from scratch;
- An update on the current status of the spider-silk yeast project; and
- Where the open-source biology field is, and where it’s going.
You are, of course, encouraged to add your own questions to the discussion. You can do that by leaving a comment on the Open-Source Biology and Biohacking Hack Chat event page and we’ll put that in the queue for the Hack Chat discussion.
Our Hack Chats are live community events on the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, February 13, at noon, Pacific time. If time zones have got you down, we have a handy time zone converter.
Click that speech bubble to the right, and you’ll be taken directly to the Hack Chat group on Hackaday.io. You don’t have to wait until Wednesday; join whenever you want and you can see what the community is talking about.