## DDT calculation question for Daniel T. DiMuzio

First, welcome to TFL. Your new book on artisan baking looks quite interesting. It's good to see a book about bread that includes a chapter on the history of bread making.

I'm going to take advantage of your nice offer (and your considerable professional experience) to answer questions by asking one: Hamelman's "Bread," the King Arthur Flour website, and The Artisan.net (just to name a few) all discuss the details of calculating desired dough temperature.

However, no one seems to address including the temperature of a soaker. I've not been able to find any reference to it, although some recipes include a soaker which uses a pound of water. I should note that I first sent this question to the King Arthur Flour Baker's Hotline on March 1. Three follow-up emails and nearly two months later, I still haven't gotten any response.

I've played with the numbers by running a comparison using the examples in "Bread." I've found that multiplying the DDT by five (the fifth item being the soaker) and including it in the calculation results in a water temperature that's in the same ballpark as the temp noted in the preferment examples given in the book, so it appears to be a factor that should be considered.

Is there any reason why soakers are not included in the published method of doing the calculation?

Thanks for any light you can shine on my so far unanswered question.

Hello Lindy,

Thanks so much for the nice welcome. I'll try to answer your question as best I can, and I'm sorry if I go on too long about it. I should edit myself more than I do.

The method of determining a desired water temperature is addressed in most professionally-oriented bread books (including mine), and they address it in pretty much the same way. I'm not going to explain it here, since anyone can read it in almost any good bread book, and you seem to be intimately familiar with it.

Let me start by saying that the traditional method of calculation is not really very precise. Any scientifically-oriented person probably knows about methods of heat transfer and how they are measured. I'm not a scientist, so I can't go into much more depth about it than that, but it's safe to say that many of them would question the accuracy of the method most bakers use.

In my observation, as seasons change, as dough hydrations vary, or as the RANGE of ingredient temps increases, this calculation, by itself and with no adjustment, becomes less and less effective. By that I mean -- if your "old dough" was kept in the 'fridge at around 40 degrees, and it forms a large percentage of your final dough, its effect on the calculation seems to exceed what it would be if the pre-ferment were at room temperature. Specifically, the "friction factor" seems wildly different than it would be for the same type of dough that uses a room-temperature pre-ferment, like a sponge.

Scientifically, that makes no sense whatsoever, so my faith in the method for calculating desired water temperature is not absolute. I jokingly referred to the "friction factor" as the "fudge factor" when explaining this to culinary students, because I often found that it needed adjustment (inexplainably) for the calculation to work, sometimes. I actually think we must conclude that this "friction factor" is a little too simply described as a result of friction only, and that it is also affected by other factors like the proportion of water to flour in a formula and other thermal factors that I can't even imagine. It almost has to be, or it would never change. Even if I'm wrong and the factor is all attributable to friction, then our method for calculating it is not very reliable when circumstances change a lot.

I use the same method as everyone else, because, realistically, it's the only tool most of us have, but I recognize that it is not a perfect method. Anybody can see that if you're using 2 pounds of old dough in a recipe, its temperature should have a much greater effect upon the desired water temp than using only 8 ounces of old dough. And yet the calculation we use takes no account of that.

Similarly, there can be other effects on DDT that aren't addressed in our traditional calculation. A mixer bowl that has been used to mix two doughs, one after the other, will be warmer than it would be if you were mixing the first dough that day, due to the heat of friction. Eggs are usually used cold from the 'fridge, as is butter. Their effect on things would be more pronounced in brioche than in a simple white sandwich bread, because there's lots more of them. And just reading the room temperature on your thermostat doesn't necessarily account for how cold or warm your bowl's working surface will be, and that affects the final temperature of your dough much more than the air temperature in the room.

So (again, pardon my being so verbose), ANYTHING you include in a dough formula will affect it's final temperature. Whether or not it's worth measuring its temperature depends, I think, upon how much of it there is in the formula, and by how different it's temperature will be from the other majority ingredients. If a soaker represents more than, say, 10% of the final dough weight, I'd probably want to take its temperature into account. On the other hand, if the temperature of the soaker is the same as for the flour, then I doubt you need to worry about it from a practical standpoint. When I know a pre-ferment represents less than 10% of my final dough weight, and it about the same temperature as the flour, I usually use the same calculation you'd use for a straight dough (no preferment), because including such a small amount of matter in the calculation seems to skew the math for no very good reason.

Your instincts about taking 5 factors into account instead of just 4 factors should work fine, as long as you multiply DDT by 5 instead of 4 when calculating your base temperature. If I wanted to include a soaker's temp in my calculation, that's what I'd do.

So, (are you still glad you asked me this question?) if you work with the same mixer every day, your doughs have a similar hydration from one to another, and they mix for about the same amount of time, you can usually use the traditional method for calculating water temp and do it effectively. You'll have to tweak it occasionally as your house gets colder or warmer through the year by making the friction factor smaller or larger, respectively. And when something changes in the formula -- like using cold milk or eggs -- you may be left guessing.

Looks like I wrote a second edition. Hope your question is answered there somewhere.

--Dan DiMuzio, former Executive Baker and Baking Instructor

Your participation in the discussions here is much appreciated.

I just got a copy of your book and am enjoying reading it. I haven't had a chance to try any of the formulas yet, but I intend to do so soon.

We could do something higher profile on the site to promote your book. In the past we've done Q&A's with Peter Reinhart or Zoe & Jeff that folks here have really enjoyed participating in. If you'd be interested in doing something like that, let me know.

I'd be happy to participate in any Q&A you'd like to arrange. In fact, I'd feel honored.

Thanks for the welcome, as well as for the opportunity.

Thanks for taking the time in responding, and in such detail, Dan. After reading your post, I'm even more grateful I asked the question because you've mentioned things I've never even considered.

Fortunately, I bake lean breads primarily so I can stick with relying on the traditional calculations. Flour, water, salt and sourdough. I do use yeast on occasion. And soakers.

My well water comes out of the tap at 42F (and not much higher in the summer), so when I first started baking bread a couple years ago, I couldn't figure out why it didn't behave like the recipe said it would. It was only after I learned about manipulating the dough temperature that the bread improved. The difference was considerable, so I run the calculation each time I bake. Bless whoever invented the Thermapen!

I do like your ten percent suggestion and will remember it.

Your expertise is much appreciated, as well as your willingness to share it.

I'm looking forward to reading your book.

You're welcome, Lindy, and thank you for the kind words.

A very warm welcome from me too, Dan! We're most fortunate to have you participating on the TFL forums, and I've learned a lot already from your posts regarding liquid and stiff starters and the DDT calculation. I think many of us will benefit greatly from reading your book!

Info on Daniel's book (and excerpts): Click me!

Thank you, Hans. It feels good to be here. --Dan DiMuzio

I'd like to pose the question in a different way. Do you feel that for a home baker, working in a non-controlled environment, without high-power mixer, but also without the pressure of a production schedule or the need to produce precisely the same loaf day in and day out to match the expectation of a customer it is even worth worrying about such things as dough temperature?

Mike

Antime that you're happy with the results of what you're doing, I don't think that anyone can tell you in absolute terms that what you've been doing is wrong. If you want to do your mixing and your fermentation without worrying about temperatures, you'll still eventually have a ripe dough and be able to bake in many cases. You just won't be able to predict when that will happen, or how it will turn out. It might take 12 hours or more. It might take 30 minutes and happen so quickly that your oven isn't even hot enough to bake.

If you desire control and, eventually, the ability to predict things reasonably, then you have to be more precise in selecting and measuring ingredients, and you have to monitor the conditions in which the dough or preferment will be fermenting. If the results obtained by maintaining that level of control don't impress you, and you find that the bread dough is no more managable than it was when you didn't bother so much, there's no way I could tell you to keep bothering with it.

Only you can decide if it's worth it. I like coffee quite a bit, and I'll pay a bit more for a premium brand, but I'm not going to get some imported Italian coffee maker that holds my water at precisely a certain temperature, and I won't throw it out after 30 minutes just because a barrista from Starbucks tells me it's no good anymore. There's a limit to what my desire for good coffee will make me do, and while investing in a more informed outlook on coffee might make for better coffee in the opinion of many, I just don't care THAT much about it.

Now, if you want to talk to other bakers about the process and the results for breadmaking, you need to speak their language, and that language has to be specific. Using thermometers, scales, and precise units of measure just makes things more easy to reproduce, alter, or identify. Bread is that important to a geek like me, but it isn't to everyone, and that's OK.

You have to decide your own range of acceptibility with regard to bread quality and the enjoyment you get with the process you use.

Thanks Dan for responding to this thread. It's awesome that you would take the time to answer these questions.

DDT is a bit of a headache for me and one I have avoided for the most part. I have always been rather confused by DDT calculations - mainly because in my pseudo-scientific mind they don't appear to accurately reflect what is actually going on when making bread.

The equal weighting of all factors seems..well odd, considering that you have completely different specific heat capacities for flour and water (and other significant ingredients)- not to mention significantly differing masses.

Then there's the 'friction factor' which confuses the heck out of me. How do I calculate this, as someone who kneads by hand? Referring to it as the 'fudge factor' just leaves me more in the dark than before.

OK, then on to 'room temperature'....how much, exactly, of the room am I incorporating into my dough?? Some air I suppose...but seriously what percentage is that and is that not subject to mix time and intensity? Would the temperature of the surface I'm working on, not be far more important than the 'room temperature'...? And if room temperature is important then surely my (hand) body temperature is also important?

To top it all off, I've yet to find a fast and accurate way to measure temperature. I have bought two (not inexpensive) digital probe thermometers over the last year or so and neither will take anything remotely approaching an accurate quick temperature reading. How, then, am I supposed to read these temperatures for the DDT calculation where, for example, 10F can make a BIG difference. Suggestions for method and/or equipment would be MUCH appreciated.

All of which (as you can probably tell) leaves me very frustrated with DDT. I'm curious to know how other people calculate and work with this. I have no doubt that it can be of great benefit to control temperature both in mixing and fermentation but I have yet to figure out how I come anywhere close to achieving or calculating this in a meaningful way.

Please help!

--FP

If you knead by hand or the fold-in-the-bowl technique, FP, the friction factor is so low is isn't included in the calculation.

The math is pretty simple. Example: you are making a straight dough and the recipe says the dough temp is supposed to be 76F.

Multiply 76 by 3. That gives you 228F - your baseline.

Subtract your flour temperature: 72F

Subtract the temperature of the room where you are mixing the bread and will leave it for the bulk fermentation: 80F

The subtotal is: 76F - and that's the temperature your water should be.

If you are using a preferment, multiply the DDT by 4 and subtract the temperature of the preferment, as well as the flour and room temps.

As discussed above, if you are using a soaker, multiply the DDT by 5 and subtract the soaker.

You might not hit precisely 76F after mixing, but you'll be pretty close. And that's much better than a temp of 85F or 50F if you're looking for consistency.

I had been using a Fieldpiece SPK1 Pocket Knife Style Digital Thermometer, available for $20 through Amazon. It was precise and pretty fast, but my daughter borrowed it. I now have a Thermapen.

Thanks - that clarified the calculation for me. I'll give it another try.

Thanks also for the thermometer recommendation. I may well end up getting the fieldpiece...thermapen is a little too pricey for me.

Cheers,

FP

As I said already in my answer to Lindy's original question (way up there near the top of the thread), there are ways to use the traditional method for calculating water temperature, and I use it all the time. Still, it isn't technically very accurate when circumstances change quite a bit. The friction factor, especially, is theoretically a constant, but my experience tells me that it's not. So don't get too worked up about the inconsistencies you perceive.

Lindy's right that there's very, very little friction in hand kneading when compared to machine kneading. Still, there is a little. Your hands alone are at almost 100 degrees F interior temperature, and they affect things a little as well. If you knead a lot, the effect is more significant. If you barely knead, the effect is minimal. I use about a 5-7 degree allowance when I'm mixing a pre-ferment by hand. Otherwise, they always come out too warm.

I use a Taylor model 9842N water-resistant pocket thermometer, and I think it's worked well, but I'm sure there are others out there that work even better. I'd just avoid using spring-type thermometers with the graduated dial -- they lose calibration very easily.

--Dan DiMuzio

Thanks for your reply.

I guess I may have been getting overly worried about the 'whys' of the calculation rather than the 'how' and getting familiar working with it.

Thanks again,

FP

Hi Dan,

Good to read your comments on here. I lecture in baking in UK and one of my students showed me your book sometime ago. Needless to say I put it into our library stock straightaway.

I find myself agreeing with you about the particular variance of FRH, as we label it in UK.

We have a slightly different means of calculating which I thought I might share; it seems pertinent, given friction factors.

For basic dough, as follows:

2[DT - FRH] = WT + FT ; where DT is required dough temp, FT is flour temp and WT is water temp, HRH is frictional heat rise from the mixer.

For doughs using pre-ferments as follows:

3 [DT - FRH] = WT + FT + Pre-FT.

Very similar principles, and I take your point absolutely that the proportion of pre-ferment used will inevitably have an affect that the formula does not take into account.

This seems like a good formula for me to use in the classroom where I have 4 different types of mixers, all with different mixing actions, therefore differing frictional heat rise.

Best wishes

Andy

Hi Andy and All,

I've put together an app that's available now on the new BB10 platform that includes a DDT calculator. I know the formula isn't that complicated but the plan is to add other features to assist in our breadmaking over time.

If anyone is interested just seach in App world for "Desired Dough Temperature". Any feedback greatfully received.

Kev.

Any plans for iOS?