your formula is correct
* S is always the sample (normally) expressed as a volume. My kit uses 15ml for S.
View attachment 83816
* distilled water is transparent therefore you can add as much as you want/ don’t have to measure it
* there are other Normalities of NaOH available, presently I use 0.1N by BSG, used to get LD Carlson 0.2N but they have some lots that are 1.00N (anyone else have problems with LD C/ I have bought kits just for good NaOH)
* the vinmetrica TA test is with a 0.133N and 5 ml sample volume.
* I frequently change sample size for example if running cranberry juice or lemon juice I don’t waste titrant and use one ml. If you use the provided syringe you increase the error by reducing sample size. You can get around this by weighing the sample to two place accuracy and multiplying by the hydrometer reading.
* I also run TA on pulpy material and record the answer as a
weight percent (work was all solid material which would be run in a blender with distilled water) If you are dealing with steeping crushed fruit in the primary a weight based number is more useful.
* I see drift on titrations with particulates (ex cider today). A good result will wait for the pH to reach steady state, in cider today that means let the probe sit with the pH 8.20 reading a minute before saying the answer is correct. Pulpy fruit like korean dogwood take longer. This can be minimized by mixing 100 gm with 100 gm of distilled water and blending (work was two minutes) or by mashing the 5.00 grams with a spoon washing the spoon in with a spray bottle, and then letting the sample equilibrate 15 minutes.
* Vinmetrica has a very good write up on TA in the SC300 manual, pg15.
View attachment 83820
some of today’s TA testing. note a small hydrometer allows a 15ml gravity sample size
note 2, the Extech has a flat glass “bulb” so I can run things like blocks of cheese or a liquid sample that is two drops (~0.05ml)