A couple of months ago I asked about acid titration as my test kit was running out of NaOH. Man... the response was overwhelming and brain boiling, but I eventually understood what it was all about. In reality it turns out that with most of the apples that I use, adjusting acid to get around pH 3.6 also results in TA around 6g/L, which is a good starting point. Also, just adding Malic Acid by taste works quite well.
In the meanwhile I have sourced a new test kit which comes with 0.1N instead of 0.2N NaOH, but I also flop backwards and forwards between using this, pH test strips, and a new pH meter. I now have a question about the different approaches used for testing since NaOH is almost impossible to get and very expensive here, so I want to minimise the use of NaOH as much as possible and zero in on the most "efficient" method.
We are now well into winter and over the next few weeks I plan to bottle the last of this year's cider (made in April/May) and want to get any any adjustments right, especially a new Red Delicious/Balerina blend that I haven't tried before.
- The "Jolicoeur el-chepo" method uses about 1/5 normal chemicals with a sample of 2.68ml ( 3.0ml x 0.89 to give the answer for malic rather than tartaric acid), with ml of 0.2N NaOH x 5 giving the TA in g/L.
- The new test kit (from Cellar Science) uses 5ml sample with ml of 0.1N NaOH x 1.5 to get the TA in g/L (I assume that this is for tartaric acid so it has to be reduced by 0.89 to convert into malic acid). This kit seems to use chemicals quite efficiently.
I was pondering how to do the Jolicoeur approach with 0.1N NaoH when I came across something by Andrew Lea which suggests a 6.7ml sample and ml of 0.1N NaOH x1 to get g/L of malic acid. I can't quite figure out where the 6.7 ml sample comes from.
As I said in my old post, chemistry isn't my strong point but it would be nice (but not essential) to know how the three methods relate to each other so that I can at least understand how each works and decide which way to go. Any input is welcome.
Cheers!
In the meanwhile I have sourced a new test kit which comes with 0.1N instead of 0.2N NaOH, but I also flop backwards and forwards between using this, pH test strips, and a new pH meter. I now have a question about the different approaches used for testing since NaOH is almost impossible to get and very expensive here, so I want to minimise the use of NaOH as much as possible and zero in on the most "efficient" method.
We are now well into winter and over the next few weeks I plan to bottle the last of this year's cider (made in April/May) and want to get any any adjustments right, especially a new Red Delicious/Balerina blend that I haven't tried before.
- The "Jolicoeur el-chepo" method uses about 1/5 normal chemicals with a sample of 2.68ml ( 3.0ml x 0.89 to give the answer for malic rather than tartaric acid), with ml of 0.2N NaOH x 5 giving the TA in g/L.
- The new test kit (from Cellar Science) uses 5ml sample with ml of 0.1N NaOH x 1.5 to get the TA in g/L (I assume that this is for tartaric acid so it has to be reduced by 0.89 to convert into malic acid). This kit seems to use chemicals quite efficiently.
I was pondering how to do the Jolicoeur approach with 0.1N NaoH when I came across something by Andrew Lea which suggests a 6.7ml sample and ml of 0.1N NaOH x1 to get g/L of malic acid. I can't quite figure out where the 6.7 ml sample comes from.
As I said in my old post, chemistry isn't my strong point but it would be nice (but not essential) to know how the three methods relate to each other so that I can at least understand how each works and decide which way to go. Any input is welcome.
Cheers!
