What are you currently doing (process), and when you say it fails, what does that mean?
In theory, there should be no problem in re-tempering, assuming that you are getting a good temper in the first place.
Thanks for your response.
My problem is that I am following the temper curve on my chocolate packaging as closely as possible [ see here: http://www.cacao-barry.com/cafr/438 ]
On the machine, I'm using a programmed melt point 112.5 F; temper point 85.7 F; and I'm using a 'temper delta' of 4.5 degrees.
I then start with the melt and the machine goes to 112.5. I select temper 2, and the machine eventually goes down to 81.2 degrees (temper point minus delta point) and on the way down asks for seed to be added (at around 90 degrees).
The machine then returns to the temper point (85.7 F) and is displayed as 'in temper'.
However, I keep getting bloom, spotting or streaks when I try this. Also, the chocolate seems to be quite thick for working condition, at least thicker than I'm used to with marble slab tempering.
(please note - this machine does not go below 80F. I discussed this with the technical support at Delta and they said it should not need to go down as far as the packaging suggests (79F). In general, their pre-programmed modes only go 3.7 degrees below temper point.)
Any responses would be greatly appreciated. I'm still getting used to tempering with a machine having done it for a long time with tabling.
Also, I don't seem to have these problems with fresh chocolate, and the pre-programmed modes (using temper cycle 2) seem to work fine on the fresh chocolate.
One thing to keep in mind is that the temper points the manufacturer recommends are designed for different equipment than what you're using - they should be used as reference points, not benchmarks.
One thing that occurs to me is that 112F is too low. 115F at a minimum, and let the chocolate sit there for at least five minutes to ensure that all the crystals are melted out. If you don't then what's left will influence seeding as you cool down.
The same is true when the chocolate reaches temper. The probe is measuring at one particular point. It can take many minutes for the crystals to spread through the chocolate. I always waited at least five minutes after the machine says it's in temper before using the chocolate to ensure more even spread of crystals.
As you empty the working bowl the machine has to work harder to keep temper. At some point, when there's less than 15-20% in the work bowl I often found that the chocolate started to streak (not bloom) because the temperatures were uneven. On a large diameter bowl that's an awful lot of surface area radiating heat into the room (and being influenced by room temperature). The difference between 19 and 22C might not seem all that different - but consistency is. If the room temp changes the temperatures of the chocolate may need to be changed to compensate.
The machines are aids - they are not panaceas. You still do need to know what properly tempered chocolate looks like.
I re-temper chocolate in my Delta on a regular basis. Beginning with the end of the previous tempering/working batch, I always spread my left over chocolate on a 1/2 sheet pan and pop it in my cooling cabiinet (re-purposed TRUE beverage cooler with a new thermostat set to 55F) for about 20 min so that my left overs have a good temper. When it comes time to re-use. I melt the chocolate out to a pretty high temp (116-118F for 72% choc) to be sure to melt ou the crystals completely. Then I always use fresh chocolate for the seed. I general;ly use the "extended temper" setting because I'm working with the batch long enough that it will over-crystalize and thicken if I try to just keep going at 88.5 F or so. I also raise the heat a bit as I go when the chocolate starts to thicken - up to as high as 90F. Keep in mind that environmental factors such as humidity and room temp can have a big effect on the chocolate.
Hope this helps,
Thank you Steve for the response and detailed reply!
I also spread my chocolate on a sheet pan and let it set but without cooler and yes, always fresh chocolate for seeding. I'm starting to think (based on feed backs) that the problem most probably might be in the inconsistent room temperature, I plan to try it again and make sure the room temperature is not higher that 21 degrees.
Thank you and I will post here once I achieve something... or not!
Have a great week-end!
first of all thank you very much for the support and detailed recommendations. I apologize for long silence as I was trying to get consistent results and also producing for local festival. It all went well. My summary will be the following:
1. The first thing which I wanted to address was the room temperature, I made sure it doesn't go above 21C. I didn't pay lot of attention to this factor and it had an impact on my attempts to re-temper it with machine.
2. The melting point is the N2 critical point, at all times for re-tempering I started to use 118F.
3. I would make sure I keep mixing the chocolate at each temperature point at least 10min.
4. Once machine prompts me to press T (temper) and add seed, I will select the temper mode but will not rush with adding seed chocolate immediately. I would add it at the level of 100F. And add seed chocolate to the front and to the back.
5. Once machine signals that the chocolate is in temper I will let it mix it for 10 min and then test it.
Also, I started to follow Steve's advice and would pour any unused chocolate on a pan sheet and let is solidify, whereas before I would leave it overnight. I find it is easier to work with it again once you remelt it.
These are my usual steps for tempering any type of chocolate that would give me good and consistent results. Apart from melting point I would use Delta pre-set temperatures.
If you have any questions let me know,