Why does it seem that pro-roasts last longer than home?

[LeoZ]

ever notice that?
buy preroasted beans, and they seem to have a good lifecycle.

home roasted, on the other hand, a couple of weeks, max.

do pro-roasters extend the roasts which could help lengthen lifespan?

another far stretch, buy lavazza. ok, not ideal, but still a great tasting bean, and not anywhere as flat as a homeroasted bean would taste, especially after 2-3 months!

[oofnik]

Yeah, I noticed that too. I can't figure it out...

[coffee_monkey]

Based on my experience and what I've read, it had to do with the type of roaster (and the heat source it uses) and the roast profile, which results in different heat transfer rate/efficiency than most home roasters.

[LeoZ]

Based on my experience and what I've read, it had to do with the type of roaster (and the heat source it uses) and the roast profile, which results in different heat transfer rate/efficiency than most home roasters.

So DRUM > AIR?

[coffee_monkey]

So DRUM > AIR?

direct flame drum > semi hot air drum > air

Roast profile also have a great affect on it... largely due to what you've done to the bean cell structure in your roasts. In a overly simplified explanation, faster roasts tend to shred up the cell walls whereas a slower/longer roast preserves the cell structure.

[LeoZ]

direct flame drum > semi hot air drum > air

Roast profile also have a great affect on it... largely due to what you've done to the bean cell structure in your roasts. In a overly simplified explanation, faster roasts tend to shred up the cell walls whereas a slower/longer roast preserves the cell structure.

unless we roast a la the ethiopians over a flame, or spend $$$$ for direct flame roasters, we are stuck with our various home setups.

expanding on my original question, how much can one extend their home roasting profile to mimic bean lifespan of these setups, without sacrificing flavor?

ive profiled up to 18mins. doesnt seem to help lengthen storage times all that much.

[coffee_monkey]

You can't ask the roaster to what it is not. That is simple physics. You can attempt to duplicate the roast profile but heat transfer method is still different. It is what it is.

Just roast less and more often.

[LeoZ]

You can't ask the roaster to what it is not. That is simple physics. You can attempt to duplicate the roast profile but heat transfer method is still different. It is what it is.

Just roast less and more often.

expanding on my original question, how much can one extend their home roasting profile to mimic bean lifespan of these setups, without sacrificing flavor?

its a hypothetical question to understand the theory, not a matter of laziness in roasting..

[coffee_monkey]

My comment was not meant to be a put-down. I own the same roasting rig you have as well as a small direct flame drum roaster. The two roasters are just... different. You can optimize your profile on each and both can produce good roasts, but the roasts will never behave the same. I am not sure if it is possible to make one emulate the other... at least I have not discovered how to yet =)

[LeoZ]

no offense taken.. i guess we need a user level rating rather than having to explain what knowledge we all have with each post..
im familiar with how sc/to roasting works, but dont understand why drum roasting creates this longer lifespan. in baking, convection is ideal, as moving air helps evenly cook the food. direct heat with grilling seals in flavors, sauteing is quick and dirty.

i guess roasting sort of meets all these categories. maybe hunched over an open flame with a shaking drum is still the ideal method. lol

[coffee_monkey]

To be honest, I have not quite figure out why a direct flame roasts will last longer than semi-hot air ones.

I do know that, the airflow is different in a perforated drum (direct flame) than a solid drum (semi-hot air). That will have an affect on the heat transfer efficiency. The drum material type, heat source (electric, infrared heater, gas, and charcoal) will also play a role. Maybe that is somewhat like the "pizza oven effect"? Baked goods made in a convection oven, no matter how good it is, will never approach a traditional brick oven.

This presentation by Arno Schwenk has a lot of good information. It's worth sitting thru:
[gvideo]http://video.google.com/videoplay?docid=-4311641929084560675[/gvideo]

As for what caused the bean to last longer... I have some theories but they are kind of shaky

[another_jim]

I don't think it's true if the airroast is done right; that is, the bean is properly dried, and not overdried, before it hits 300.

Among specialty coffee people; I am in a very small minority on this: my take is that both drum and air roasters are outdated technologies. The big industrial roasters, who need to turn sows ears into purses, have been going through a lot of technologies in the last 40 years, and have settled on convection roasters with mechanical agitation (the closest home set up is an SC/TO, provided the air temp is properly controlled -- i.e. PIDed). This allows both the bean temperature and the oven temperature to be separately profiled. There is simply no reason to believe that drum roasts are better -- those with unlimited budgets wouldn't dream of using one.

One factor is that pro roasts come in valve bags, while home roasts are mostly stored in mason jars. This, along with less than perfect profiling will make the difference.

The simple fact is that roasting is exactly like espresso, the problem is almost always the person, not the machine.

[hbuchtel]

another far stretch, buy lavazza. ok, not ideal, but still a great tasting bean, and not anywhere as flat as a homeroasted bean would taste, especially after 2-3 months!

I had the same experience when I switched from pre-ground "major roasting company" beans to home-roasted (brewed with a moka pot).

My hypothesis at the time was that some companies blend with the expectation that the coffee will be stale when brewed.

From the other posts here it seems the roasting also plays a large part...

Henry

[Branden]

One factor is that pro roasts come in valve bags, while home roasts are mostly stored in mason jars. This, along with less than perfect profiling will make the difference.

I have often wondered what the effects of a sealed mason jar are and how this changes the way a bean stales. When I open a mason jar, for the first few days the smell is rather flat while in comparison when I store my homeroasted beans in valve bags the aroma appears to develop to a much fuller extent.

What are the effects of CO2 that is trapped within a mason jar until opened?

Branden

[Kaffee Bitte]

I have often wondered what the effects of a sealed mason jar are and how this changes the way a bean stales. When I open a mason jar, for the first few days the smell is rather flat while in comparison when I store my homeroasted beans in valve bags the aroma appears to develop to a much fuller extent.

What are the effects of CO2 that is trapped within a mason jar until opened?

Branden

And on similar lines. Are jars with one way valves a good way to go?

[DaveC]

And on similar lines. Are jars with one way valves a good way to go?

I've always thought so, and you can make reusable ones.

http://coffeetime.wikidot.com/one...lve-jars-home-made

[Kaffee Bitte]

I've always thought so, and you can make reusable ones.

Are the one way valve jars that are sold by, say Bodum or other companies also good?

[DaveC]

Are the one way valve jars that are sold by, say Bodum or other companies also good?

I don't know, have not seen or used them. Do you have a web URL?

[luca]

This might well merit a separate topic, but one thing that I have mentioned before as intriguing me is that commercial drum roasters invariable start with a much higher drop temperature than most home roasters. Could that have something to do with it?

[LeoZ]

This might well merit a separate topic, but one thing that I have mentioned before as intriguing me is that commercial drum roasters invariable start with a much higher drop temperature than most home roasters. Could that have something to do with it?

i still dont understand the benefit of a start temp and calculating the drop temp. so it goes from 200 to 150, then ramps up? is this really doing much besides taking a minute off the total roast time?