Yoghurt Whey

[Curry Diva]

I've been wading through yoghurt posts and not able to find any appropriate info. I thought perhaps some forum members may be able to help.
Both my mother and I have a tmx and use exactly same yoghurt recipe, ingredients and technique (Valerie's online recipe via superkitchenmachine website)
The query is: I get hardly any whey formation and my mother gets loads. It's not a problem to stir back in of course, but we can't figure out what is making the difference to the vast extra whey, and we think surely we should be able to get to the bottom of it.
Only thing I can think of is that I've been making it for 8 months and she's been doing it for a month. Could the cultures from the starter be that different, given age?
TIA. 

[judydawn]

I have no idea CD as I have rarely made yoghurt (I did get whey on each occasion though) but it sure is an interesting and puzzling question 

[Kimmyh]

I use that method too and find I get a bit of whey too. However it sort of builds up over time in the fridge. I thought it might be because I was using just a little at a time and putting it back in fridge till next time. When it gets a fair bit, I drain some and use the whey  instead of water or milk in scones and bread recipes.

[cookie1]

I've never been much good at making thermomix yoghurt. I do find they commercial yoghurt develops whey over time too.

[Curry Diva]

Thanks Folks. I make at least liters a week as our family is big consumers and we love it naturally. I'm hoping to pick up a person who knows what factors influence whey formation. My batches have neglible whey whereas my mothers has significant.

[Debbiebillg]

Not sure if this helps, but I buy yoghurt culture from Green Living. They told me that the production of whey as time goes on indicates that the culture is still active. Now this part could be a sales ploy of course ......... but they said that when you use some yoghurt as the starter you can gradually introduce bad bacteria and they don't really recommend it. They did say though that if doing this, don't leave it till the yoghurt's nearly finished to get the yoghurt for the next batch. Each time the yoghurt's opened and used (and if you have kids and they may lick the spoon then put it back in the yoghurt etc), new bacteria can be introduced. So always reserve the yoghurt for the next batch straight away.

I just use the culture from Green Living because we don't always have yoghurt (and the yoghurt culture is pretty cheap anyway).

[judydawn]

I wonder if the reason is that Mum takes much longer to eat her batch CD and yours doesn't get a chance to develop much because you go through it a lot quicker.

[cookie1]

Judy I think that makes a lot of sense. Thanks.

[Curry Diva]

Oh ladies these are all fabulous ideas.
JD: yes this is true, we do consume ours quicker. Good point. (sorry I neglected to say in the last post we make "6"L minimum per week, wheres my mum would only make 2-3 I'm thinking). The whey forms straight away for her, ie once spooned carefully into the fridge container out of the thermoserver.
DB: oh yes also a good point. I'm exceptionally careful with the starter piece, it's always a fresh sample (but I'm the only one serving it out in our family and I'm a tad OCD with clean spoons and double dipping etc etc. I had never thought of that point, so thank you. I need to check what my Mum does in that department)
My yoghurt is still setting very well after 9 month of using the same starter, and its creamier than when I first began, so I'm not too sure that I have bad bacteria overwhelming the good ones??
I posed the same question over on a Facebook forum, and Leonie from ThermoFun indicated to me it would be age of the culture, and as long as I can ensure a clean non contaminated starter is used, my Mums batch just has a few months worth of catching up to do on mine. Check out her link at http://docs.com/VT3P (bottom of second page speaks to it)
Now what I plan to do is 2 things: buy a fresh batch of pot set yoghurt and make it myself to see if I get whey. And have my Mum use my 9 month old starter and see if she gets less whey. Keeping everything else as constant as possible of course. I love experiments - will keep you posted as to the outcome/
Thanks again for helping us "whey" through our journey!!
CD