What Size Roaster Do I Need?

Finding a roaster with the appropriate capacity for your needs is really complex and fraught with pitfalls. What if you buy too small a roaster? You'll have to go spend more time and money on the buying process again, and you'll be roasting around the clock. Buy too big a roaster and it will sit idle, possibly limit the diversity of your coffee offerings, and put a financial strain on your business.

This article hopes to help you make the optimal, most efficient roaster purchase decision for your business. We'll discuss the various criteria for consideration (your business type; the hours you can devote to roasting; current and projected roasted needs; approach, output and efficiency), categories of roaster, and projected output (taking into consideration approach) for each roaster we offer. If you'd like to go over your specific situation with us, reach out!

I. You

There are many unique types of people and businesses that roast coffee; however, most purchasers of coffee roasting equipment fall into one of the following categories:

- Enthusiast/part-time. You roast coffee for fun, perhaps at home, or perhaps as a small-scale ancillary business function (i.e. a brewery roasting their own coffee for use in coffee beers). Strict business needs don't necessarily have to dictate your roaster purchase. Consider getting a Proaster CR-01 and SR-002.

- Wholesale roastery. This has three subcategories:

1. Solo operator. If this is you, you likely only have half your time available to devote to roasting. The rest of the time is spent ordering, cleaning, maintaining social media, packaging, delivering, and doing all other business functions. This is one of the few scenarios in which you might purchase a roaster and be limited in your roasting hours due to other business activities.

2. Partnership. If this is you, you might have one partner handle all roasting duties and the other handle everything else. Different partnership structures divvy responsibilities differently of course, but the significant differentiating factor in light of our topic is that you have the ability to devote a person to full-time roasting - that allows you to maximize the value of your roaster. 

3. Scaled-up wholesale roastery. If this is you, you have an employee or team devoted to every business function. You might have a full-time roaster or roasting team allowing you to maximize the time your roaster is in operation. 

- Cafe/roastery. You have a cafe and a roaster. Your main (or only) customer for roasted coffee is your cafe (and your cafe's customers). Wholesaling is not a significant business function. As an aside, you may exclusively serve your own roasted coffee in your cafe, or offer other roaster's coffee as well (either in a 'guest roaster' scenario, as part of a multi-roaster model, or en tandem with a local roaster who may provide you with cafe equipment and/or service). There remain two subcategories of cafe/roastery:

1. Single location. Aside from having to roast and handle roasting business functions, you also have to run a cafe or hire someone to do so (and likely work cafe shifts too). That means you could have to split your time in thirds and/or hire someone. You can likely still handle everything yourself if you have the right roaster and aren't trying to wholesale your coffee.

2. Multiple locations. Your focus will fragment further at scale. It's likely time to get a cafe manager or a dedicated roaster/roasting team.

- Cafe/roastery + wholesale. Without question, you're now running two businesses. You'll essentially need a 'front of house' team devoted to the cafe side, and a 'back of house' team devoted to the roasting business. 

Understanding the category your business falls into is the crucial first step to finding the right roaster. 

II. Available hours to roast

We have customers who run our roasters 80 hours/week for years. A well-built, well-maintained, well-cleaned roaster will be able to withstand heavy usage and last forever with standard wear-and-tear replacement parts. That said, planning on 80-hour production weeks isn't necessarily the best way to go. What if you land a massive new account? Are you going to roast 120 hours? Conversely, getting a roaster that's too big for your business needs isn't ideal. With the exceptions of a solo operator/wholesale roastery and/or a single location cafe/roastery without a wholesale program, I would encourage customers to select a roaster they can use 40 hours/week. If you use it less you're not maximizing the value - in other words, you might've purchased too much roaster. If your business grows to where you have to roast more than 40 hours/week, you'll be able to double the production and afford a bigger roaster. 

Solo operators and cafe/roasteries without wholesale programs might be better served planning on 20 weekly roasting hours. 

Don't forget to consider cleaning time - likely intermittent for sample and profiling roasters, a few hours per week for small and standard production roasters, and maybe a full day each week for industrial roasters. Don't forget to leave time to sample roast, profile roast and cup either.  

III. Current and projected roasted coffee needs

If you're an enthusiast, this is less relevant. 

If you're a wholesale roastery, take stock of your current accounts. This article isn't meant to be a be-all end-all for how to project roasting volume, but consider customer types (keeping in mind that the numbers below could vary wildly):

1. Cafe (coffee-forward) - could be 25lbs/week if slow, maybe somewhere around 75lbs/week is typical, and a slammed cafe probably does 200lbs/week

2. Farmer's market - similar numbers to cafe.

3. Grocery - lots of volume here. If we're talking about a local/regional/national chain, this could be thousands of pounds each week. 

4. Office - small, typically, but can very - five lbs/week, but can scale up to massive.

5. Hospital - like an office. 

6. Brewery - can vary wildly. Often seasonal.

7. Restaurant - often really small (five lbs/week) but if they have brunch and/or a coffee focus it could be like a coffee-forward cafe.

8. Churches, temples and other religious organizations - like a restaurant.

There are of course other customer segments, but these should at least cover the basics and give you a map for figuring out your own process. Now, survey you market: how many competitors are trying to serve the same market? How many potential customers of each type are in your market? What percentage of the existing market can you convert? Can you add new entrants to the market? Can your market transcend your local area? Can you do direct-to-consumer online sales?

If you're a cafe/roastery not exclusively serving your own coffee you could start really small (i.e. CR-01). Or, you may be starting around 200 lbs/week and need a bigger machine. 

If you're a multi-location cafe/roastery, this is easy - just count your volume.

If you're a cafe/roastery + wholesaler, see above regarding wholesale. 

Be smart here, methodical, and realistic. Know that a sample and/or profiling roaster is going to be a solid long-term investment, as you'll always need them; a small production roaster is the most common category that gets used, then sold when more capacity is needed; a standard production roaster is a terminal-level roaster size-wise for most coffee businesses; and an industrial-sized roaster absolutely is. For purchases in the last two categories, plan on the equipment sticking around for a decade or more. 

IV. Approach, output and efficiency

1.Approach. Do you roast light, dark, medium, or all of the above ("full-spectrum")? This is important to our discussion primarily because it will inform the typical shrinkage you might expect during roasting (green coffee loses weight as you roast it). The ICO uses a figure of 16% when calculating shrinkage; the SCA recently came out with a chart that uses 18%; in my experience, 16% is accurate-to-high for a third wave roastery that does light roasts; however, if you're doing dark roasts you could expect a number north of 20%.

The secondary reason consideration of approach is important is because if you're doing dark roasts and/or commodity coffee - profiles and coffees where the roast is more forgiving - you might prioritize efficiency over cup quality and thus be able to do 80% capacity batches or even 100% capacity batches. On industrial-sized roasters, this is the norm. For specialty roasters, it's not uncommon for batch sizes to be smaller (40% to 75%, or perhaps even lower). This has a practical basis (i.e. a small batch size to accommodate a small order) and a cup quality basis as well (manipulating heat transfer). 

2. Output. Vis-à-vis batch size and weight loss, this is a facet of approach. If you're prioritizing cup quality, your typical batch size will likely be lower (perhaps 60%, to provide a single controversial but useful number) than if you're prioritizing efficiency above all else. Your shrinkage will likely be a percentage in the mid-to-low teens. If you're prioritizing efficiency, you're likely doing 80%+ capacity batches, and your percent shrinkage could range from the mid-teens into the low twenties.

3. Efficiency. This is primarily about the number of roasts you accomplish per hour. This is profile-dependent, machine-dependent, as well as operator-dependent. 

If you're roasting light, you may have profiles as fast as 9:30 (or less); conversely, some long, dark profiles can take up to 20 minutes. 

Most small machines have a single blower, preventing the operator from roasting and cooling simultaneously (without rigging up an ancillary cooling system) - such machines require sequential time to roast the coffee, time cool the coffee, then time to get the machine back to its charge settings. That will limit all but the most skilled operators doing light roasts to three roasts per hour. On standard-sized machines with two blowers, four roasts per hour should be the norm except in instances where the profile is extremely long (15+ minutes). Industrial-sized roasters generally output three roasts per hour, as the large bean mass causes roast profiles to stretch in length. There are exceptions to each of these rules, of course.

A skilled operator should be able to achieve maximum efficiency on any roaster with even a modicum of roasting experience, familiarity with the roaster, roasting environment, and coffees. Everyone makes mistakes and ruins the occasional batch, but efficient roasting is easy. First Crack teaches a course specifically on the topic - reach out if you're interested!

V. Categories of roaster

1. Sample (50g-250g batch). Sample roasters are exclusively for sample roasting. Some manufacturers claim otherwise, but sample roasters truly are limited to the exclusive task of sample roasting because the bean mass is too small for profiles to transfer up to profiling or production machines, in a way not dissimilar to the aforementioned lengthened roast times on industrial roasters. That said, every business, regardless of size, needs one of these. We sell Proaster's SR-002. The SR-002 is a simple, straightforward, traditional sample roaster. 

2. Profiling (a.k.a. small production - 200g to 1.5kg batch). Roasters that fall into this category are the CR-01 (Proaster used to make a 500g roaster too, but it’s special order only now and you have to order 10 of them). These roasters are absolutely able to handle production roasts and often are used for competition coffees. They're just as capable of handling quality roasts as larger roasters; their capacity is simply very small. Having a roaster this size is very useful though, even if you're a large operation. While having a profiling roaster isn't necessary, it allows you to profile for larger roasters without blowing through tons and tons of green coffee. First Crack offers a course on how to transfer profiles from profiling roasters to larger roasters (as well as from brand to brand) - reach out if you're interested! The only downside to a profiling roaster is simply that it lacks the capacity to carry the load for anything beyond an enthusiast, or a single-location cafe/roastery with no wholesale program. As always, there are exceptions - we've had customers run a multi-location cafe/roastery with a wholesale program solely using a CR-01 (80+ hour roasting weeks), and while the equipment is up to the task, there are better roaster fits for such a workload. Again, these make an excellent investment for any roastery simply due to the money saved in green coffee expended profiling.

3. Small production (5kg). This is where you begin to see features shared with larger roasters - powerful burners, a larger footprint, etc. These roasters are big enough to be a primary production roaster for a small roastery. They're powerful enough to hit four roasts per hour if you're a skilled operator and have profiles that allow for it. As with any smaller roaster, these can be used to profile for larger roasters, but they aren't as efficient in a green coffee conservation sense as the profiling category of roasters. These roasters have a lower price point than larger roasters but often don't offer the value (capacity for your money) that larger roasters do. They are also the fastest category of roaster to be outgrown. While people starting on a profiling roaster tend to keep them and add a larger production roaster, owners of small production roasters often sell them when needing more capacity. 

4. Standard production roaster (10kg-30kg.). Green importers look at roasteries who purchase 2,000 60kg bags as being a significant benchmark. That roughly translates to 20,000 roasted pounds each month. A roastery that size is in the top 20% of roasteries by output. As such, a standard production roaster is viewed by many as a terminal-level investment. Even the smallest roaster in this category - the 10kg - can handle such volume, albeit at an 80+ hour roasting week. Roasters in this category tend to be some of the most efficient roasters in terms of output - common roast profiles are short enough to accommodate four roasts per hour, and the machines in this category all have two blowers allowing for simultaneous roasting and cooling. To oversimplify, roasters in this category should be able to output just under 1,000 lbs/mo. per kilo of capacity, at 40-ish roasting hours/week. Lastly, businesses that outgrow a standard production roaster often keep them for their high-end coffees, micro lots, auction and competition coffees. 

5. Industrial drum (60kg-240kg). This category represents the largest drum roasters available. These roasters offer the most efficient throughput of any drum roaster. Full plant integration comes into play heavily. Automation is standard. Ancillary equipment - not just loaders, destoners, and afterburners, but silos, green and roasted conveyors, color sorters, grinders and more come into play. Purchasers of industrial drum roasters do themselves a great service by looking at full plant design when investing in a roaster. The roasters can produce coffees of outstanding quality, but it is exceedingly rare for businesses needing equipment this size to prioritize cup quality over efficiency on these machines. There absolutely are exceptions, but physics come into play - this is the top end of drum roasting capacity. Even if you scale up drum construction, airflow, paddle geometry, drum speed, etc., it simply becomes a challenge to replicate profiles time-wise due to the bean mass, and it becomes exceedingly hard to have even bean mixing as related to airflow. This is not a brand-specific notion, but rather one tied to bean mass. Specifically, getting consistent airflow from the back of the drum to the front is an engineering feat. That is not to say it can't be done (the brands represented in our offerings absolutely do the best job of this), nor is it to say everyone roasting on roasters this size makes inferior-quality coffee, but roasters this size usually end up being used with a focus on throughput. Another consideration is green - if you have a 60kg bag that costs $1,000 and four 60kg bags of another coffee that each cost $250, you'll likely move the first coffee at the same pace as the second coffee. In that case, even though you could throw the 60kg bag into the full-bagger machine, you'd likely be better-served by roasting it on a smaller roaster that would allow you to pace your roasting better. Roasters this size also tend to require longer profiles, so three hourly roasts is a more realistic projection than four. 

6. Bühler InfinityRoast. This line of roasters are in their own category. These are the most exciting roasters on the market today. They are capable of achieving incredible throughput - up to 4000kg per hour on a single machine. These roasters are able to achieve roast profiles one might expect on any other machine. You can even flash-roast coffee in as little as three minutes. The design allows for maximum, even mixing of bean mass, and sufficient airflow in a way not dissimilar to tangential roasters. These are state-of-the-art machines, setting the standard in large-scale production roasting. The InfinityRoast line features in-roast color analysis; incredible efficiency; full-plant design with full operation possible by even one or two operators; and so on. Quite frankly, these are incredible roasters with unparalleled engineering and features. They are truly top-of-the line. The InfinityRoast products can handle all the throughput you'd ever want without compromising cup quality.

At this point you should know the type of business you are; the hours you can devote on a weekly basis to roasting; your current and projected roasted needs; your approach, realistic output, and efficiency; and, what category(/ies) of roaster you need. Consider how you will approach sample roasting, profiling (which can be don on larger machines, just at the cost of green coffee), and production roasting; with that information you should be able to figure out which roaster(s) to purchase based on their capacity. 

VI. Projected output across the product line, based on roast approach

1. Sample.

Proaster's SR-002 is the one dedicated sample roaster in our offering. It does 100g batches. Advantage: you get a true sample roasting experience, with at least two shots to get it right (green samples usually arrive in roughly 250g quantities). You could do smaller batches too and roast a sample in several different ways so as to get a fuller picture of that coffee. Disadvantage: this is a single-purpose roaster. You can't profile on it.

2. Profiling

From this point on I'll provide three output scenarios, meant to approximate three different types of approach:

1) third-wave light roast. 60% batches, 16% loss, 3 roasts per hour (4 roasts per hour on small and standard production roasters)

2) full-spectrum roasters. 75% batches, 19% loss, 3 roasts per hour (4 roasts per hour on small and standard production roasters)

3) dark roast. 80% capacity batches, 22% loss, 3 roasts per hour (4 roasts per hour on small and standard production roasters).

I'll again note that not everyone is going to fall into one of these approaches. You can always tailor the numbers to suit your own projections. 

A few final notes:

- 40-hour roast weeks are presumed in the output projections below. 

- Rounding was used to provide ballpark numbers rather than set-in-stone values.

InfinityRoast

This line can essentially handle any capacity requirements up to and including 4,000 kg/hr. throughput. 

In summary:

If you're roasting for fun, get a CR-01. Consider getting a sample roaster too.

If you're a solo operator/wholesale roastery, figure our your projected monthly roasted needs and pick the roaster that meets them (keep in mind, the numbers above are for 40-hour weeks, so you'll need a roaster twice as big if you're only roasting 20 hours each week). You'll also want to purchase an SR-002 to sample roast with, and possibly a CR-01 for profiling. 

If you're a wholesale roastery in a partnership or scaled up, simply pick the roaster that meets your projected monthly roasted needs. Consider a sample and/or profiling solution too.

If you're a single-location cafe/roastery adding your roasting to your existing roasted offerings, you can likely get by with the CR-01 + SR-002. 

If you're a single-location cafe/roastery exclusively roasting your own, presuming you have 40 hours to roast, you can get by with a CR-01 + SR-002. If you only have 20 hours to roast, you want a CR-03. If you only have 13 1/3 hours to roast (i.e. a third of a 40-hr. workweek), you'll need a CR-03 unless you exclusively roast dark.

If you're a multi-location cafe/roastery, simply calculate your projected monthly needs and pick the roaster that meets them. Same goes as before regarding sample roasting and profiling. 

If you're a cafe/roastery + wholesaler, same thing - figure out your projected monthly needs, pick a roaster that meets them, consider a sampling and profiling solution. 

This article isn't perfect. It doesn't take into account usage. It presumes the operator isn't ruining batches. It doesn't take into account maintenance downtime. It presumes the operator is prepared, running the equipment efficiently, and so on. While not perfect, it at least shows the methodology behind finding the best-sized roasting system to meet your needs. Feel free to reach out to us if you'd like to go over which roaster best suits your specific situation.