Hario Mini Mill Slim Plus: A Budget Hand Grinder Worth Considering
The Hario Mini Mill Slim Plus (also called the Hario MSS-1DTB) is one of the most affordable ceramic burr hand grinders you can buy. At around $30-40, it's often the first grinder people buy when they want to step up from pre-ground coffee. The question most people have is simple: does it actually produce a good enough grind to make a difference? The answer is yes, with some important caveats.
I used a Hario Mini Mill as my daily grinder for about eight months before upgrading. It taught me a lot about what matters in a grinder, and I still keep one as a backup for travel and camping. Here's everything I learned from daily use, including tips that made it work much better than it did out of the box.
Build and Design
The Mini Mill Slim Plus is small and lightweight. It's about 6.5 inches tall, weighs around 250 grams, and fits easily in a backpack or carry-on bag. The body is transparent plastic (the hopper and catch container) with a ceramic burr assembly in the middle.
The "Plus" version is an update over the original Mini Mill. Hario added a silicone grip band around the bottom section, which makes it much easier to hold while grinding. The original was smooth plastic that got slippery, especially with wet hands. This silicone band is a small change that makes a big practical difference.
The Handle and Ergonomics
The folding metal handle is functional but not comfortable for long grinding sessions. If you're grinding 20+ grams for a pour-over, your hand will get tired. The handle is short, which means less mechanical advantage, and you have to grip the body firmly with your other hand to keep it stable.
For a single cup (15-18 grams), it's fine. For grinding larger batches (40+ grams for French press or cold brew), it becomes genuinely tiring. This is a budget grinder limitation that more expensive hand grinders solve with longer handles and better bearings.
Grind Quality: Honest Assessment
The ceramic burrs in the Mini Mill Slim Plus produce a grind that is good enough for most filter brewing methods but far from perfect. Let me be specific about what that means.
Medium to Coarse Grinds (French Press, Cold Brew)
This is where the Mini Mill does its best work. At coarser settings, the particle distribution is reasonably consistent. French press cups are decent, with acceptable body and moderate silt. Cold brew comes out smooth because the long steep time is forgiving of grind inconsistency.
Medium Grinds (Pour-Over, Drip)
For V60 and Chemex, the Mini Mill is adequate but shows its limitations. You'll notice slightly uneven drawdown times because the grind distribution includes more fines and boulders (oversized particles) compared to better grinders. The cup is still much better than pre-ground, but it lacks the clarity and sweetness that a $100+ grinder would produce.
Fine Grinds (AeroPress, Moka Pot)
At finer settings, the Mini Mill struggles more. The ceramic burrs produce a wider spread of particle sizes, and the adjustment mechanism doesn't have the precision to consistently hit the same fine setting. AeroPress is forgiving enough that this works okay, but for Moka pot, the inconsistency can lead to over-extracted, bitter cups.
Cannot Do Espresso
The Mini Mill cannot grind fine enough or consistently enough for espresso. Don't try. You'll get channeling, sour shots, and frustration. If espresso is your goal, you need a different grinder entirely. Our best coffee grinder roundup has options that handle espresso properly.
The Grind Adjustment System
The Mini Mill uses a nut adjustment at the bottom of the burr assembly. You remove the catch container, turn the nut clockwise (finer) or counterclockwise (coarser), and reassemble. There are no click stops or markings, which means you're adjusting by feel and memory.
This is the biggest downside of the Mini Mill. Without click stops, it's hard to return to a precise setting after changing it. I developed a system where I'd count full turns and quarter turns from fully tight, and I'd write down settings for different brew methods. It's clunky but workable.
My Settings Reference
After a lot of experimenting, here are the settings that worked best for me:
- French press: About 7-8 full turns from closed
- Pour-over (V60): About 5-6 full turns from closed
- AeroPress: About 3-4 full turns from closed
- Drip/batch brew: About 6-7 full turns from closed
Your mileage will vary depending on bean density and freshness, but these are reasonable starting points.
Ceramic vs. Steel Burrs
The Mini Mill uses ceramic conical burrs, which is worth understanding. Ceramic burrs are harder than steel and stay sharp longer, but they're also more brittle. If a small rock or piece of debris gets into the grinder, ceramic burrs can chip. Steel burrs in the same situation would just deflect it.
Ceramic burrs also generate less heat during grinding, which some people believe preserves more volatile flavor compounds. In practice, hand grinding is slow enough that heat isn't really a factor regardless of burr material.
The main downside of ceramic burrs in this price range is precision. Manufacturing tolerances for cheap ceramic burrs are wider than for steel, which contributes to the particle inconsistency I mentioned above.
Who Should Buy This Grinder
The Hario Mini Mill Slim Plus is the right grinder for:
- Complete beginners who want to try fresh-ground coffee without a big investment
- Travelers and campers who need something lightweight and compact
- Students on a budget who can't justify spending $100+ on a grinder yet
- Backup grinder owners who want something for emergencies or travel
It's not the right grinder for:
- Anyone who drinks espresso
- People who want precision and repeatable settings
- Daily pour-over brewers who taste the difference that grind consistency makes
- Anyone willing to spend $60-80 (at that budget, a Timemore C2 is a much better buy)
If you have even a slightly bigger budget, stepping up to a $60-100 hand grinder like the Timemore C2 or 1Zpresso Q2 will give you significantly better grind quality and a much nicer adjustment system. Check our top coffee grinder picks for comparisons across price tiers.
Tips for Getting the Most Out of Your Mini Mill
After months of daily use, I found several tricks that improved my experience:
Shake gently while grinding. A slight side-to-side motion while cranking helps beans fall into the burrs more evenly and reduces the effort needed.
Don't overfill the hopper. The hopper holds about 24 grams, but grinding works better if you only load 15-18 grams at a time. Overfilling creates pressure that makes the handle harder to turn.
Grind in one direction only. Resist the temptation to go back and forth. Consistent clockwise rotation gives a more even grind.
Mark your adjustment nut. Use a small dot of nail polish or a Sharpie mark on the adjustment nut so you can visually confirm your setting without counting turns every time.
Clean it weekly. Remove the burrs, brush out retained grounds, and reassemble. Stale grounds left in the burr assembly will taint every cup.
FAQ
How long does it take to grind with the Hario Mini Mill?
For a 15-gram dose at a medium grind, expect about 60-90 seconds of continuous cranking. Finer grinds take longer. It's not fast, and it requires more physical effort than higher-end hand grinders with better bearings.
Are replacement burrs available?
Yes, Hario sells replacement ceramic burr sets for the Mini Mill. They're inexpensive (around $8-12). If your grind quality degrades after a year or two, a new burr set will restore it.
Can I use the Hario Mini Mill for Turkish coffee?
Not reliably. Turkish coffee requires an extremely fine, powder-like grind that the Mini Mill's ceramic burrs and adjustment system can't achieve consistently. You'd need a dedicated Turkish grinder or a high-end hand grinder like the Comandante or Kinu.
Is the Slim Plus better than the original Mini Mill?
Yes. The added silicone grip band, slightly improved burr assembly, and better overall fit and finish make the Slim Plus the clear choice. If you're buying new, get the Plus version.
Final Thoughts
The Hario Mini Mill Slim Plus is a $35 grinder that performs like a $35 grinder. That sounds like a criticism, but it's not. It's the cheapest way to start grinding fresh coffee, and it's good enough to prove to yourself that fresh grinding makes a noticeable difference. Use it until you outgrow it, then upgrade knowing exactly what improvements matter most to you. That's the best $35 you'll spend on your coffee journey.