Latest / Internet of Things with Fexingo: Connected Devices, Sensors, and Industrial IoT / How IoT Sensors Are Tracking Beer Fermentation in Microbreweries
Transcript
- Lucas: So you walk into a craft brewery taproom, order a hazy IPA, and it tastes exactly the same as the last batch you had three months ago. Most drinkers take that consistency for granted. But the people running those breweries will tell you it is brutally hard to pull off. Luna: Because fermentation is still partly a dark art. Temperature swings, yeast health, even the barometric pressure on a given day can throw a batch off. Lucas: Exactly. And traditionally, the brewer's main tool is a clipboard and a thermometer — checking the tank manually every few hours, writing down numbers, adjusting valves by hand. It works, but it leaves gaps. Especially overnight. And in a small operation, that brewer is also handling ordering, cleaning, and taproom staffing. Luna: So IoT sensors step in to fill those gaps. That's what we're looking at today — how wireless sensors are turning beer fermentation from an art into a data-driven process. Lucas: Right. And I want to anchor this in a specific place: Barrel Theory Beer Company in Saint Paul, Minnesota. It's a well-regarded microbrewery that opened in 2018, does about 2,000 barrels a year. Not huge. They started experimenting with IoT fermentation monitoring about a year ago. Luna: What sensors are they using? I picture something that goes right into the tank. Lucas: Two main things. One is a wireless temperature probe that sits in a thermowell inside the fermenter and transmits data every five minutes to a cloud dashboard. The other is a specific gravity sensor — that's the one that gets interesting. Specific gravity tells you how much sugar is left in the beer, which directly tracks fermentation progress. Luna: And the traditional way to measure specific gravity is to pull a sample from the tank, put it in a hydrometer, read it, write it down, then dump the sample. It's manual, it's messy, and you're only getting a snapshot. Lucas: Right. The IoT version uses a floating device that sits on the surface of the beer inside the tank and transmits gravity readings continuously. No sampling, no waste, no forgetting to check at 2 AM. Barrel Theory installed these on three of their twelve fermenters as a pilot. Luna: And what did they learn? Lucas: They found that their fermentation curves were a lot more variable than they thought. Especially during Minnesota's winter months, when the brewery's heating system cycles on and off at night. Temperature swings of three to four degrees Fahrenheit were causing some batches to finish faster and others to stall out. Luna: A stalled fermentation is a huge problem for a small brewery. If the yeast stops working before all the sugar converts, you either dump the batch or serve a beer with off flavors. Lucas: Before the sensors, they were catching stalls maybe half the time during overnight hours. Now, the system sends an alert to the brewer's phone if the specific gravity hasn't moved for twelve hours. They caught three stalls in the first six months that would have turned into lost batches. Luna: Three batches saved. At maybe 200 gallons each, that's a lot of beer that would have been poured down the drain. What's the dollar figure? Lucas: Rough estimate from the head brewer: each batch costs about $1,200 in ingredients, labor, and overhead. So saving three batches is $3,600 — which more than covers the sensor kit cost. The whole setup for three fermenters ran about $1,200 for the hardware, plus a $50 monthly subscription for the cloud platform. Luna: So payback in under a year, even on a pilot. That's compelling. Lucas: And that's just the direct savings. The bigger win is consistency. Barrel Theory's head brewer told me that before the sensors, their year-over-year batch variation on a flagship IPA was about seven percent in final gravity. After six months with sensors, that dropped to under three percent. Luna: Which means customers get the same beer every time. And for a small brewery, brand loyalty is everything. You can't afford a bad batch that makes people think your IPA went downhill. Lucas: Exactly. And this isn't just a craft beer story. The same sensor technology is being deployed in wineries, kombucha producers, even industrial ethanol plants. But the economics are especially favorable for small producers because they don't have the staff to do round the clock manual monitoring. Luna: So what's the catch? Why isn't every brewery doing this? Lucas: Two barriers. One is technical: the specific gravity sensor has to be sanitized properly before each use, and if the brewery's cleaning protocol isn't perfect, the sensor can get coated with hop residue or yeast, which throws off the readings. Barrel Theory had to adjust their cleaning cycle a couple times. Luna: So it's not entirely set-and-forget. The brewer still has to maintain the sensor. Lucas: Right. And the second barrier is cultural. Some brewers are proud of their hands-on process. They feel like letting a computer tell them when fermentation is done takes the craft out of craft beer. But the younger brewers coming up — they grew up with data. They see the sensors as a tool, not a replacement. Luna: I think that's going to be the key. The breweries that adopt this early build a consistency advantage. And in a market that's getting more crowded — there are over 9,000 breweries in the US now — consistency is a competitive edge. Lucas: Absolutely. Barrel Theory is now planning to equip all twelve of their fermenters. They're also testing a dissolved oxygen sensor that could help them reduce oxidation in hoppy beers. That's one of the hardest problems in brewing — keeping oxygen out after fermentation. Luna: The trend we're seeing is clear — IoT is moving into every corner of food and beverage production. It's not just about cutting costs; it's about making a better, more repeatable product. Lucas: And speaking of what keeps this kind of reporting possible — we should mention something quickly. This show is completely ad-free, and it stays that way because a small group of listeners chips in monthly through buy me a coffee dot com slash fexingo. Luna: Yeah, it's a tiny thing, but it genuinely covers the hosting costs and the time we put into research. If you've gotten something useful out of an episode like today's, that's the way to keep it going. Lucas: No pressure at all. Just wanted to pull back the curtain. So back to the beer — the dissolved oxygen sensor Barrel Theory is testing costs about $400 per tank. If it cuts oxidation losses by even one batch per year, it pays for itself immediately. Luna: And if they roll that out across all twelve tanks, that's a potential $4,800 annual saving from one sensor type. Plus the consistency improvement. Lucas: Exactly. This is a textbook case of industrial IoT at a small scale — where the investment is modest, the data is actionable, and the ROI is clear. The sensor companies are starting to notice. There are now at least four startups specifically targeting craft beverage fermentation monitoring. Luna: Are any of them public? Or is this still venture-backed territory? Lucas: Mostly venture-backed. One company called BrewSensor — not public yet — raised a seed round last year. Another, FermentIQ, is bootstrapped and profitable. But the big industrial sensor players like Emerson and Endress+Hauser are starting to offer scaled-down versions of their fermentation monitoring kits for small breweries. Luna: That's a sign the market is maturing. If the big guys are coming downmarket, there's real demand. Lucas: Yeah. And I think we'll see more of this — not just in beer, but in cheese, yogurt, even bread. Any fermentation process where temperature and time matter, IoT sensors can add consistency. The question is whether the producers see the value. Luna: Barrel Theory's answer is clearly yes. And they're proof that you don't need a huge operation to benefit. Lucas: Right. So if you're a homebrewer listening, or even just someone who appreciates a consistent IPA, know that IoT sensors are quietly making that possible. And that's a good thing — especially on a hot summer day. Luna: I'll drink to that.