## Sourdough Calculator

Here is a Google spreadsheet for calculating sourdough hydration, starter quantity, etc.

Values are entered in the green cells. You should not be able to enter data in the red cells. These are calculated values.

For starter, enter the flour quantity and desired starter hydration, and it will calculate the water quantity to use.

For dough, enter the flour weight and the values for water, starter and salt in baker's percentages. The spreadsheet will calculate the weights and volumes of water and flour in cups.

At the bottom are total flour and water weight, dough weight and dough hydration.

Except for the volume (cup) measurements, the spreadsheet is "weight agnostic". You can use any unit of weight: grams, ounces, pounds, etc. The cup measurements are based on grams. In cell F2 you can enter the weight of one cup of flour. The spreadsheet will display cups next to the flour and water weights.

This can be used with yeasted bread as well. Manually adjust the baker's percentage value in cell B9 until cell C9 gives the weight of the proofed yeast (water + yeast weight).

You should get an error message if you try to enter data in protected cells. As the creator of the spreadsheet it is not possible for me to test cell protection because I always have permission to change protected cells.

Please report any errors or problems, particularly with cell protection, here.

https://docs.google.com/spreadsheets/d/1P7RBFZle75Enp2dmxX3vPFXCiq0cphXtMnkGUiwdkoY/edit#gid=0

That is great, thank you.

I also have a great app on my iPhone that calculates all , comes in handy and I use it a lot.

Bookmarked!

It says I have to have permission and won't let me view the document without it.

am waiting.

This is my first experience using Google spreadsheets. For everyone who requests permission to access it, I get an email. I then have to approve each request individually, filling in each person's email address each time. So it may take a while. I've looked and can't find a setting to share with everyone globally.

is way above me :)

Just received the invitation. Thank you.

However it is my first time to and I don't wish to confuse you, or myself, and start changing things without better knowledge.

Hi - I too have been working on the same thing as you over the past 2 years or so. I see you have locked all the cells you need to - that's essential. But to get it so no one has to bother you for permission, just go to the blue Share button, and once the box comes up select the 'anyone can edit' button. You will find they can edit your gold cells but not the others that you locked. Yours looks a little like mine did a year ago - until I started wanting something I could easily use on my cell phone. It looks like you figured the sharing out as I had no problems getting in.

My travels down this road are here https://docs.google.com/spreadsheets/d/1Pgn0Glm5jTwAY3wuuJPCrMUB0EAK5i4QEH-r8jmfGnE/edit#gid=1963385935 I'm always interested in feedback. There are a couple of underlying differences: you allow for control of salt % - I fix it at 2%. I have fields for timing, temperature and logs, which when I'm trying to sort out a specific sourdough problem are quite useful to refer back to. This is also my public version - I've got a private one too.

One other thing about google docs is that if they are downloaded as excel files, all the protection disappears - great for excel nerds who want to mess with someone else's work (as I did when I first tried this stuff going on a couple of years back.)

Abe - there are some default values in there, so go ahead and change. The spreadsheet will be automatically saved with each edit.

All pending requests have been approved at the moment.

With your permission.

I'll have another look tomorrow morning (office is crazy now). When it's nice and quiet i'll sit down, with a cuppa, and will add/change.

I believe you can download the spreadsheet as an xls file for use in Excel or OpenOffice (the latter is free), so you can have a copy of it on your own computer.

...I rely on my phone which has internet access. Only have a computer at work. Will try and see if my phone is compatible. Work better in the mornings. I'm off to take care of all the bread I eat at the gym soon.

To download go to file, then download as.

Tom C

I found the well-hidden setting that lets anyone with a link to the page edit the spreadsheet. It should no longer be necessary for me to grant access individually.

Enter data ONLY in the green cells.

If you overwrite the equations it isn't much of a calculator :)

Hopefully some changes to the permissions have fixed this.

Simple, easy to use, even I can do it.

Good stuff.

Simplicity is often the best.

Recommended.

Enter the starter hydration in cell B4 as a non-percentage, i.e. don't add a percent symbol. For example, if you want 125 percent starter hydration, simply enter 125 with no percent symbol. The spreadsheet will make it a percentage. Otherwise, the water weight in cell C5 will be off by a factor of 100!

I'm glad you find it useful. Abe, do you get an error message if you try to enter numbers in the red cells? You should. Protecting cells in Google spreadsheets is weird.

Sent you some thoughts and ideas. I'll highlight here...

1. Flour shouldn't be changeable in the starter. Just the hydration. We already have percentage of starter in the recipe. That plus hydration of starter should be enough to workout the amount of flour to be added in the starter.

2. What has to be assumed is that everyone's starter is 100% hydration. What happens if someone is trying to add from a starter that is 125% hydration or 75%?

3. Let's assume that can be sorted out... we also need to be able to add in, for example, a 100% hydration levain but then final dough might be 60% hydration. The calculator should take that into account. e.g.

As far as I can see the 66% hydration only takes into account the flour + water but not the starter.

Am I correct?

The only way around this would be to create from the starter a 66% levain but most people don't do this. And even if one did we are still assuming that the starter we are starting with is 100% hydration which isn't always the case.

Abe, thank you for vetting it out.

Re: #1: The beauty of this spreadsheet is that the baker can make an arbitrary amount of starter and use any portion of it in a recipe. That's why I divided it into two sections: "starter" and "dough". I always make a little more starter than I'll actually need in a recipe. The surplus goes in the fridge.

Re: #2: You can make the starter any hydration you want. The final dough hydration figure takes into account both the amount of water in the starter and the amount of starter in the dough.

Re: #3: It can do everything you want it to. In your example you have fixed the flour weight at 600 g and your starter at 10 b.p. You have fixed two of the variables involved in dough hydration: flour and starter. Now all you have to do is determine the amount of water. You manually enter different water weights until you arrive at the dough hydration you want. In this example you add 64.3 b.p. to arrive at a dough hydration of 66%. The water weight has to be arrived at manually because it doesn't know which variable you want to solve for to achieve the desired dough hydration, which is a combination of starter water and dough water.

I could have the user enter the desired dough hydration and solve for the amount of water to add. Would this be more useful or create problems? In its current state you can take an existing recipe and calculate the hydration of it. I originally wanted to be able to calculate the dough hydration of S.F.SD, the recipe for which is given elsewhere on this board, but I wanted to make S.F.SD using liquid starter and arrive at the same dough hydration.

I believe it was proth who was working with the BBGA who are trying to standardize this kind of thing. I would appreciate hearing from him. The dough hydration takes into account the starter flour, starter water, dough flour and dough water, which I believe is the correct way to do it.

Thanks again, Abe, for working with this.

Was under the impression that when typing the hydration into the recipe I was asking for the final hydration. But upon further inspection this isn't so. The final hydration takes everything into account including the starter. So that does change after it's reworked everything.

I think this is workable (but not clear). And once it is clear there shouldn't be too much trouble in toggling amounts to get it just right. But I am also thinking that when people think of bread recipes they automatically think of the final hydration they are aiming for and I think you'll be helping them a lot by taking this into consideration. I regularly find myself working out the recipe i'm aiming for i.e. 66% hydration, trying to take into account the starter I've added. Your spreadsheet could help with this.

But as you say it does work the way it is now just takes a bit of toggling. If you leave as is then make it a bit more clear that this is happening.

I'll take another look soon. But all looks good.

Oh yeah, also make clearer that the programme is taking into account that the starter (before being fed) is 100% hydration. I think many people take this as a given i.e. when nothing is given we take it as the standard 100%. I do like it as this allows me to take from my 100% hydration starter and try sourdoughs with stiffer or looser starters and it works it out for me.

All this is positive criticism (ideas) as I like the programme very much. Great idea.

Here is the BBGA protocol for baker's percentage. Now all I have to do is read it and make sure the calculator is in conformance.

http://www.bbga.org/files//2009FormulaFormattingSPREADS.pdf

http://www.thefreshloaf.com/node/40458/help-maths

The spreadsheet has undergone a major rebuild to put it about in the format specified by the BBGA. I now have to triple-check it to make sure the math is right, and go over the cell protection again so people don't mess with the equations.

Now if I let the user specify a desired final dough hydration, will the ss calculate the amount of straight water to add? Suppose the user wants to get more hydration by using more liquid starter or by increasing the hydration of the starter? Gotta think about these things. That would be a totally separate sheet anyway. The basic ss isn't changing.

The starter hydration can be any value.

Just had a look and like the new format. I see what you have done and I like the way it takes the starter into account. It does update the final hydration and weight. Appreciate that the other issue would have to be taken into consideration and perhaps a separate sheet but nicely done.

One last thing that has just occurred to me. In the 1st column one should be able to request the starter amount.

In the 2nd column (starter column) I think the only thing one should be able to change is the hydration of the starter. That is all the info the spreadsheet should need for the calculation.

The rest should all be worked out for you.

So for example....

1. starter percentage : 20% (of 1000g flour)

2. starter hydration : 100%

3. Then there should be 3 boxes on how to feed your 100% hydration starter at the ratio of 1:1:1...

First box: 66.66 Starter

2nd box: 66.66 flour

3rd box: 66.66 water

you are actually taking into account that we're adding in fed starter. Keep it simple.

Hi Abe -

The proportion of starter is entered in baker's percent in cell B9.

It makes no assumptions about the amount of starter that will be made. The starter is kept separate from the dough for this reason, thus you enter the starter flour amount in cell H6. I have to keep it flexible to accomodate as wide a range of "use cases" as possible.

Keep it like it is. It works very well!

Again, enter data ONLY in the green cells. DO NOT enter data in a cell which isn't green or which has an equation in it. You screw up the whole thing when you wipe out the equations like that, and then it is no good to anyone as the calculations are null and void.

If you mess up and enter a value in the wrong place, use the undo arrow near the top of the sheet.

Only doing green cells. When I alter it on my computer does it alter it on yours?

If you're using the on-line version, it changes it on everyone's computer. Alternatively, you can download it and store a copy on your computer and do with it as you please.

Sorry but this is new to me

I don't know about BBGA, but on this SS, there is an apparent conflict in the first column. It automatically counts the starter flour and water in the respective rows for each, then also has the place for the user to enter starter percent. I know there needs to be somewhere to specify the starter percent, but it seems to conflict with the rest of that column, and add confusion to the information represented there, because the amounts of the flour and water in the starter are then counted twice in that same column. Maybe move that user-defined starter percentage cell to the bottom of the middle column, where the starter amounts are figured?

DavidEF: I'm not following you.

The dough and starter are figured completely separately, as they should be. For example, you could make 5,000 grams of starter and use only a portion of it in the dough as specified in cell B9, putting the rest into storage.

Cells B7, B8 and B9 are where the dough portions are entered in B.P., and cell J6 is where the flour weight is entered. Cell E8 is for the hydration of the starter only, not the dough. Cells C3 - C9 are the total weights of the finished dough.

If you could refer to specific cells by their coordinates, such as J6, B9, etc., that would be helpful. I'd be willing to deviate from the BBGA spec if some part of it is truly confusing.

Here is the link again. There have been lots of cosmetic changes: https://docs.google.com/spreadsheets/d/1P7RBFZle75Enp2dmxX3vPFXCiq0cphXtMnkGUiwdkoY/edit#gid=0

I deleted an unneeded column. The flour weight goes in cell I6.

https://docs.google.com/spreadsheets/d/1P7RBFZle75Enp2dmxX3vPFXCiq0cphXtMnkGUiwdkoY/edit#gid=0

Deleted an unneeded row. Cell coordinates have changed accordingly.

https://docs.google.com/spreadsheets/d/1P7RBFZle75Enp2dmxX3vPFXCiq0cphXtMnkGUiwdkoY/edit#gid=0

Dave - I have set the sharing so that anyone with a link can access it. I need to review the cell protection, though.

It now does some error checking for erroneous values.

https://docs.google.com/spreadsheets/d/1P7RBFZle75Enp2dmxX3vPFXCiq0cphXtMnkGUiwdkoY/edit#gid=0

You should have access to all the user-changeable cells now.

I can definitely relate to your process!

is this based? 100% or 160%?

Dries

You can make the starter any hydration you want. Enter the desired value in cell F6.

I made a spreadshhet to take care of my calculations as well, but I get different result than you and I cant figure out why.

This is my data:

Total amount of Dough:

1548 gramsTotal amount of starter:

180 gramsTotal percentage of starter:

20%Hydration of starter:

100%Hydration of Dough:

70%Amount of Salt in dough:

2%These are my calculations:

Total amount of Flour = Total amount of dough / (Total percentage of ingredients / 100)

1548 / (172/100) =

900 gram of Flour(I did'nt count in the starter in the total percentage of ingredients, maybe this is were I go wrong)

Total amount of Flour in the Starter is 180 / 2 =

90 gramsof Flour.I then subtract the amount of flour in the starter from the total amount of Flour to find out how much Flour I need:

900 - 90 =

810 grams of FlourIn your spreadsheet I get

806,3 gramsof Flour. Its a minor difference, but Im just wondering were I go wrong.There are different ways of dealing with the percentages when dealing with starters. Personally I use the same method you do when I figure out my doughs. I get 810g of flour, 540g of water, and 18g of salt (plus 180g of 100% hydration starter). Just use your own spreadsheet since it is more in tune to your way of thinking. I actually take it one step further and don't use percentage of starter, but percentage of pre-ferment flour (in this case a sourdough starter). That way it can use any hydration of starter. Plus this allows me to go back and forth between different kinds of pre-ferments (or just a straight dough).

If you make your own spreadsheet and change the formulae, of course you're going to get different results.

maybe something like... "You do it wrong because..." instead of just stating the obvious.