Help needed with age old bicarb of soda questions

[benjamin163]

Hello, 

 

I understand baking powder contains the correct amount of acid (cream of tartare) needed to react with the bicarb to get a chemical reaction and a rise.

I get that this makes it ideal raising agent when there is no acid in a recipe for bicarbonate alone to react with.

 

But isn’t it the case that almost all recipes can be adapted to have some sort of acid in them, perhaps in the form of brown sugar, lemon juice, buttermilk? Why use baking powder if you can put acid in most baking recipes without spoiling them? Is it simply an unnecessary added extrea in those circumstances? Or is it a safety net that some bakers like to fall back on in case for whatever reason, the bicarb chemical reaction doesn't work? Or is there yet another reason for adding baking powder?

 

The next question. How much acid is actually needed for the bicarbonate to do its job of creating air but also how do I ensure there is no bicarb left after all the acid is used which might spoil the taste.  If the answer is a ratio of 4 parts acid to five parts bicarbonate as I have read, how do you measure that in different acidic ingredients like brown sugar or buttermilk? How do I know how much acid is present in each of these ingredients in order to use the correct amount of bicarbonate?

 

Any help gratefully received.

[AlaMoi]

there are recipes that use both baking powder and baking soda.

most baking powder is 'double acting' - first the acid-base chemical reaction, then co2 released at higher temperatures.

 

unless you have accurate equipment to measure the pH and acid availability, plus a microgram scale to weigh out the baking soda, , ,

it's a bit tricky to match up the quantities exactly.

then, not all milk/buttermilk/acid ingredient/etc is consistent from batch to batch . . . meaning you might have to test each carton/container/whatever each time you do the bake.

 

I think mos use baking powder for the simplicity and reliable results.

too much baking soda can indeed affect the taste of things - so there's little room for 'error on the side of caution'

 

 

 

[benjamin163]

28 minutes ago, AlaMoi said:

there are recipes that use both baking powder and baking soda.

most baking powder is 'double acting' - first the acid-base chemical reaction, then co2 released at higher temperatures.

 

unless you have accurate equipment to measure the pH and acid availability, plus a microgram scale to weigh out the baking soda, , ,

it's a bit tricky to match up the quantities exactly.

then, not all milk/buttermilk/acid ingredient/etc is consistent from batch to batch . . . meaning you might have to test each carton/container/whatever each time you do the bake.

 

I think mos use baking powder for the simplicity and reliable results.

too much baking soda can indeed affect the taste of things - so there's little room for 'error on the side of caution'

 

 

 

Thanks so much for this reply and apologies for the further questions it unlocks!

If baking powder is double acting (ie it reacts with its own acid AND it reacts with heat, then why use bicarb at all? What is the benefit of bicarb? Is it that you can use far les of it to get a rise (as long as there is acid in the recipe) and therefore it won't impair the taste of your bake?

I'm thinking it's so difficult to be sure EXACTLY how much acid is in a dish that adding a little baking powder is a good way of making sure you will get a rise. But given you need to use roughly 4x as much of the stuff as bicarb, it's good to use bicarb where possible so that you aren't tainting the taste. Is that the long and short of it? 

[Pete Fred]

39 minutes ago, benjamin163 said:

If baking powder is double acting

 

Be aware that this applies to the US but is probably not the case if you're in Europe. I say probably because I've read so much conflicting advice online. When I have a fail with American recipes I reflexively blame it on this rather than operator error. 😏

[AlaMoi]

baking soda reacting the 'the same amount' of acid will give up about twice as much CO2.

in big broad brush strokes,,, denser batters often use baking soda (e.g. Irish soda bread) - or a combination of both.

 

certainly with experimentation you could find how much baking soda is need for a specific recipe - I think the baking powder brings more reliability to the baking.