A mixer’s RPM is useful to know for bread baking. Cuisinart didn’t supply the information and didn’t respond to an email, so I measured it using a laser tachometer that I ordered for this purpose (no expense is too great for science):
Ouch, Gene. This is why peer review is a good thing. However, that is the same question that occurred to me when I sought out the official RPMs for my former KA. Since they didn’t see fit to tell me, I drew the unsubstantiated conclusion it didn’t matter.
I was measuring the planetary. For this tachometer to work, you have to put black tape on the rotating object, then put a piece of reflecting tape on that, so that there’s a good contrast, and then you focus the beam on where the reflective tape will appear as the object rotates. The problem with attempting to measure the spindle speed is that the planetary moves the spindle around in its own orbit so that the reflective tape will appear in difference places; the laser beam will be aimed at the wrong place. Any suggestions?
Anyway, the planetary and the spindle rotate in opposite directions, and it seems that I can visually see the reflective tape twice in one rotation of the planetary; this suggests that the spindle is rotating at the exact same speed as the planetary, just in the opposite direction. This is sort of the opposite case of our Moon, which rotates in the same direction as it orbits the earth at the same rate, so that we always see the same side.
As far as the dough is concerned, I’m not sure which RPM is meaningful to it as far as gluten development is concerned. The important thing, however, is not that measurements are “correct”, but that they’re consistent across all people making them. So when Hammelman talks about RPM, what is he measuring? My results are consistent with his, so maybe all mixers have the same issue.
For machine tools the important measurement is surface speed. Usually expressed as inches per minute and determined by the difference in speed between the cutting tool and the work surface. It seems to me the one reliable measure would be the velocity of the largest diameter of the attachment. So one would have to calculate the radial velocity from the rpm of the spindle then add or subtract the velocity of the planetary motion.
And having just spent several minutes counting rotations on my KA I conclude that it is surprisingly difficult to determine the gear ratio. It must be some irrational fraction so that the paddle doesn’t return to the same spot for a long time. In addition the absolute velocity of the paddle would be some periodic function based on the changing radius due to the planetary motion. Wow much more complex that one would first think.
On my Cuisinart, the spindle returns to the same position when the planetary returns to the same position, which is why I think the RPM is the same on both. I would also think that this would make the gearing simpler, but that’s a guess. The RPM range I have for the Cuisinart is almost exactly the same as my KA.
Is it helpful for adjusting mixing times when moving between mixer brands, or is there more to it than that?
That’s essentially it. More specifically, it’s useful for converting kneading times given for a mixer type to your own mixer. Hammelman stresses that you have to know your RPMs in order to adjust the times he provides for a spiral mixer to your own mixer. To a good approximation, the number of rotations of your mixer determines the level of gluten development. He says something like 900 rotations gives you 80% development, so you need to know in your mixer how long that takes. He gives the times in only two speeds, first speed and second speed, but this assumes a spiral mixer and the times will be much longer in planetary mixers like most of us have.
Cool. And I imagine that there’s an rpm equivalent for hands as well- i.e., each fold and press of hand kneading equals something like two rotations on a mixer.
Cool. And I imagine that there’s an rpm equivalent for hands as well- i.e., each fold and press of hand kneading equals something like two rotations on a mixer.
That’s the theory. But Hammelman does point out that it’s an approximation. I would suspect there is some efficiency factor “k” that would have to be added to the formula to take into account the differences between a dough hook and your hands, or between the various styles of dough hook. When the dough is very wet, I’m very skeptical that the dough hook is having much effect at all when it just tugs at the puddle of dough at the bottom of the mixer.
I think this idea serves as a reality check; I know when constructing formulas and testing results, it’s so easy to start deviating into never-never land as one change leads to another. Often it’s better to regroup by resetting your formula back to something standard before moving forward again. It’s like when you get lost geographically, it’s often better to go back to some known point before attempting once more to seek out your destination.
A mixer’s RPM is useful to know for bread baking. Cuisinart didn’t supply the information and didn’t respond to an email, so I measured it using a laser tachometer that I ordered for this purpose (no expense is too great for science):
Wow, there is a huge difference in machines which brings me to this question: when I follow a recipe calling for ‘high’ speed, should the actual setting and duration of beating be reduced on the 6 quart model since recipes were tested on the 5 quart model?
Wow, there is a huge difference in machines which brings me to this question: when I follow a recipe calling for ‘high’ speed, should the actual setting and duration of beating be reduced on the 6 quart model since recipes were tested on the 5 quart model?
Personally, I would use these figures as more of a diagnostic tool. If a cake came out a bit tough, it might warrant a lower RPM or shorter amount of mixing. That’s why even the most explicit of recipes isn’t a substitute for experience with a piece of equipment and an ability to troubleshoot problems. I just bought a Bosch Universal, and I’m having to reconstruct all the mixing steps for my recipes.
Wow, there is a huge difference in machines which brings me to this question: when I follow a recipe calling for ‘high’ speed, should the actual setting and duration of beating be reduced on the 6 quart model since recipes were tested on the 5 quart model?
Personally, I would use these figures as more of a diagnostic tool. If a cake came out a bit tough, it might warrant a lower RPM or shorter amount of mixing. That’s why even the most explicit of recipes isn’t a substitute for experience with a piece of equipment and an ability to troubleshoot problems. I just bought a Bosch Universal, and I’m having to reconstruct all the mixing steps for my recipes.
Wow! Congratulations! A Bosch Universal is very cool!!
I did think it mandatory to know what you are looking at and at what point you need to use your own judgement.
I feel Rose’s recipes are the only recipes on which I can rely without question.
I have several classic baking books and only use the recipe as a guide because the equipment on which the recipes were developed do not measure-up to the well-equipped kitchen of today.
Thanks for your response Charles and enjoy your new Bosch!
I feel Rose’s recipes are the only recipes on which I can rely without question.
I think her mixing method is very forgiving regarding mixing times. I’ve played around with the times and haven’t seen much of a difference in the product. For bread, I rarely place much faith in mixing or rising times, even Rose’s. Bread dough, unlike cake batter, will let you know when it’s ready. For my version of Rose’s cracked wheat loaf, it requires 14 minutes in the Bosch on setting 3 before I can get a good window pane. And, the Bosch heats up the dough a lot, so I have to chill the soaker and poolish before mixing.
Anyway, to bellyache about the Cuisinart, I really hated this machine. The tilt head just drove me nuts, because it hit the top of the cabinet. My old KA was a lift bowl and didn’t do that. And while the Cuisinart timer was nice, it was also on the side where it was awkward to see and reach unless I turned the machine sideways. The narrow, tall bowl made it tough to reach in and scrape or stir with a spatula, and the dough hook had a hard time incorporating ingredients and grabbing hold of small dough quantities.
I never looked into the Cuisinart. When I thought mixer, KA is the only one which came to mind. The timer on the mixer is a novel idea. I use this one, recommended by CI and I love it. Only $13:
Charles, is the Bosch a good replacement for a KA for someone who is just a beginner? I ask because my son is getting married and he wants a mixer. Neither of them bake. Would it eliminate the need for other appliances?
However, that is the same question that occurred to me when I sought out the official RPMs for my former KA. Since they didn’t see fit to tell me, I drew the unsubstantiated conclusion it didn’t matter.
