What to call first crack
Topic: What to call first crack (10 msgs / 303 lines)
First an introduction: my name is Kevin and I am in
the business planning stages of opening my own coffee
house with a goal toward roasting on-site in the 4th
Recently I purchased a Fresh Roast in a package with 6
half pounds of different varietals. I've roasted about
18 batches so far some utilized in a custom blend.
Part of my goal in home roasting is that I am
obsessive about coffee. The other part is to learn
about this aspect of coffee so that I know something
when we take roasting operations in-house. I therefore
keep a log and monitor 1st crack time and temp, 2nd
crack time and temp, how long between 2nd crack and
cooldown and some other information on a PalmOS based
log I developed.
My question is this:  I notice that at first crack
only one or two beans pop and betwen that point and
sometime later a few more join in and then a bunch
before things quiet down again waiting for second
crack.  When do I call 1st crack 1st crack? Is it when
the first bean pops or when the majority of them are
Welcome, Kevin, I hope you will tell us more about your coffee house as it develops. What kind of place do you envision, etc.
I don't think there is an accepted standard way of timing first crack, second crack, etc. Are you using the data for comparison? If so, the important thing is to be consistent, to measure it the same way each time. That said, it is not that easy to do because different varieties behave differently. Some will have loud distinct cracks and some will be less noisy. Some coffees begin cracking abruptly and other begin gradually.
Of course, the more constants you have (ambient temperature, amount of green coffee per roast, etc.), the better your data will be. Others on this list will have more (and perhaps conflicting :-) ) suggestions, I'm Sure.
Kevin---I hope all goes well in your new
endeavor.  Someone on the list (was it Rick? Or
Angelo?) noted a couple of weeks ago that one
standard is to listen for cracks which come
within ten seconds of each other...when that
happens, you can say that the crack has begun. 
But the early ones?  Call 'em hypersensitive...or
early birds...or sprinters...or whatever you
It seems you're gathering this info for your purposes only and not to match
up with others. In that case, I think consistency is the key. Call the first
crack by your convenience (and I do mean 'convenience' because you're going
to be filling in those little worksheets a lot) but most of all do it the
same for every batch. Then it's always apples to apples.
Learn to distinguish first and second cracks by their sound. It comes easy
with experience. Some beans will have a first that is spread out in time
with many outliers. Others will be more compressed, just picture a bell
curve. Some beans depending on roast profile will make scattered pops or
snaps all through what is supposed to be a quiet period between first and
second. Some of these snaps sound like second crack, but occur long before
they are supposed to. In my experience, second tends to begin more abruptly
than first, with few outliers beyond 10 seconds even in a slow roast.
I record the first crack as beginning with the first outlier unless there is
some oddball that sounds off more than 30 seconds before it is supposed to.
Some beans will make only 3 to 5 pops through the entire first crack which
may take 1.5 to 2 minutes to complete. This of course depends on profile.
Fast roasts tend to make many pops in a short period and more total pops
than a slow roast. The end of first is a key event for me, since I begin
timing here for lighter roasts. I use the 10 second rule here, but for slow
roasts, maybe 20 to 30 seconds is appropriate.
I tend to ignore temperature, it is subject to too many errors.
hi kevin and welcome - i won't sound in on what to call the beginning of 
first crack but simply share my recent experience switching from the hwp to 
the alp.  i have been amazed at how much easier it is with the alp to 
discern 2d crack in particular but also first crack and to gauge the shifts 
in the bean.  if you are thinking about roasting with a drum roaster 
ultimately you might want to consider investing in the alp (or the hottop 
when it comes out).  good luck and do keep us posted on the coffee shop 
developments.  where will you be located?
loving my new alp in columbus
That question is kinda like asking "When is water hot?".
I bet everyone on this list uses a slightly different criteria for making
that determination.  I first use smell.  About 30 seconds before the first
bean pops, there is an intoxicating smell.  I breathe it in deeply and savor
it's aroma.  Sure enough, a renegade bean pops and then sometimes another...I
wait...then a couple more...when several start popping, I consider it first
crack.  The end of first crack poses the same type of dilemma, when is the
last of the first crack (so I can gauge the time between first and second).
I find myself saying..."OK, that was the end.  No, there's a few more.  OK,
that's it.  No, this is the end.  I usually just 'call it' and stick with it,
then start timing it until beginning of the second crack.
As long as you are consistent with your method, it really doesn't matter.
Each varietal has different crack characteristics and it even varies from
batch to batch.  Log it the same way every time and use a system that helps
you, and you'll be OK.  It won't compare with everyone else, but don't even
I agree with EdNeedham.  Considering the variety of beans and the different 
process/brand of machines used to roast individual consistentency is the 
important element in determining what your definition of 1st crack is.
To add some more confusion, I noticed this weekend that the cracking can
depend on the batch size.  I'm using a popcorn popper, and I had the two
realizations/discoveries this weekend:
-- More beans (1/2 vs 1/3 cup) reduces the air flow and raises the air temp.
Still plenty of agitation, but the roast developed faster, and I got a more
vigorous "crack" than some of my other roasts.
-- More beans = more cracks: there's just more of them to make noises.
There is no question that batch size is a variable which affect the dynamics
of the cracks. If one were to do a batch that is so big the beans have
trouble turning over, the ones on the bottom will heat up very quickly, and
will crack much sooner than other beans in the same batch.  In that case,
the first crack is very prolonged, with many outliers at the beginning and
Conversely, a small batch will turn over very quickly, and will allow the
air to escape out the top more readily and more quickly.  The larger volume
of air cools down the coils, delaying the first crack, and heating all the
beans more evenly.  If the batch is large enough to slow the air
sufficiently, the batch will get hot enough to crack.  The crack will last,
theoretically, a much shorter time, as the beans are much more consistent in
I have a speed control on my fan, and an on/off switch on my heating coils,
so I can use almost any batch size (within limits) and still get consistent
roasts, and can delay or accelerate the cracks depending on what profile I
am developing.  The degree of control can be very fine, unless the roaster
is overloaded.  Often I go slow up to about 350 degrees or so, to allow all
the beans to get a consistent color.  Then I slow down the fan to quickly
achieve first crack.  I can keep the temp and turnover rate right on the
edge of first crack, to prolong it, or I can accelerate directly into first
crack very quickly.