On the positive side, it's insanely easy to brew with it. Measure your ingredients, load them into the system, load the recipe, hit a button, and wait. It's mostly a hands-off process from there. When it's finished (and because I don't want to ferment in the corny keg), I transfer the beer to a kettle, chill it, then transfer to a fermenter. This process takes about 20-30 minutes. Cleanup is easier than with my previous system, and parts of that are automated as well. The Zymatic gives off a "brewery" aroma if you're within about 10-20 feet of it, but is undetectable outside that range (at least to me). The beer coming out of the Zymatic is as good as any I've made elsewhere.
On the negative side, the machine has its limits. Compared with other brewing systems, it's not as efficient. Depending on the recipe, grain crush, and mash profile used, I've seen brew house efficiencies as low as 55.3% and as high as 76.4%. With The Grainfather, I don't recall ever seeing an efficiency below 70%. So you need more grain to hit a gravity target with the Zymatic than with The Grainfather. That combines with the fact that the Zymatic has a 9-pound grain limit (versus The Grainfather's 20 pound limit). This means the bigger, higher-gravity beers aren't as easy to brew with the Zymatic. They're possible, but you're going to be resorting to things like adding malt extract, doing reiterated mashes, or boiling down the wort to increase the gravity.
The Zymatic is also unpredictable in its finished volume amounts. Despite specifying a 2.5 gallon volume in the recipe crafting tool, I frequently end up with 2.1 to 2.2 gallons of wort. This isn't a big deal, but if you were planning on that extra (approximately) half gallon for some reason, you'll be frustrated.
Gravity is also somewhat unpredictable, but if you crush the grain yourself (in the 0.045 range) and measure the water carefully, you'll come out pretty close. For my last few batches, I've seen:
- Belgian Single: Estimated gravity 1.047 SG, actual 1.050 SG
- Belgian Dubbel: Estimated gravity 1.075 SG, actual 1.067 SG
- Saison: Estimated gravity 1.055 SG, actual 1.058 SG
- Tripel: Estimated gravity 1.085 SG, actual 1.086 SG
- Saison 2: Estimated gravity 1.068 SG, actual 1.065 SG
With the exception of the Dubbel, those all came within 3 points of the estimated gravity. I'm not sure why the Dubbel came out so low. Maybe I didn't measure the water as carefully.
Probably the worst thing about the Zymatic is that it can overflow its grain tray during the mash if you are not staying on top of it. A mash that brushes up against the 9 pound limit, or one that includes a significant amount of wheat or oats, or just giving it a bit too much water, can result in a real mess. The very first batch I made, their Pico Pale Ale kit, foamed excessively out of the grain tray, overflowed the drip tray, and made a huge mess on the floor that took a while to mop up. I had only left the machine alone about 10-20 minutes. Two other batches of the 12 I've made have had foaming or overflow problems as well. One of those was relatively minor and resulted in a tiny puddle on the table. The other was huge. It covered most of the table top, almost the entire shelf underneath the table top, and a path across the basement floor to the drain, where it puddled up a fair amount. That took a while to clean up. I've made it a habit to check on the machine about every 10 minutes during the first 30-40 minutes of mashing, just to watch for potential foaming or overflow issues. Making sure the machine is level, that you're measuring water carefully and not getting too close to the grain limit will help.
The other frustrating thing about using the Zymatic is the recipe editor. You have two mash profiles by default - a normal single infusion mash and a high efficiency mash. The normal infusion mash is incredibly inefficient. That's the batch I had 55% efficiency on. The high-efficiency profile delivers on its promise but can only be edited in their "advanced" mash profile editor. That editor is easy enough to work with, but there's a catch. If you change the profile and save it, then go back to change an ingredient (e.g., to correct the alpha value of the hops), the changes in the advanced editor are discarded. If you're not aware of this quirk, you'll find that the mash doesn't behave as you intended (it goes back to the default). This is a huge bug that I'd think PicoBrew would fix, but they don't.
Still, I give the device credit. It's allowed me to focus on recipe development, to brew on days when I couldn't afford the time to stand over a mash and kettle, and to easily make smaller batches (and thus avoid accumulating too much homebrew). Despite its frustrations, I am overall happy with it.