September 19, 2012 - 11:55am
When to refrigerate starter?
My stater is now mature and very active. In a few days I wont be able to bake for a week so I would like to store my stater in the fridge. When should I place it in the fridge? After I have refreshed it and it has double again? Thank you.
Refresh it at 1:20:20 then wait one hour before refrigerating. If your refrigerator is set to 35°F, you can go a week or 10 days without feeding again and it will recover in one feeding. Beyond that it is likely to take a few refresh cycles to recover full activity.
So please go with 1:5:5 first (starter: water: flour.) The rest applies. :)
What helped me to understand the storage piece in starter maintenance was thinking about it in terms of food and going to bed.
Would you rather go to bed hungry?
By allowing the yeast and LABS to eat all the food available you are essentially putting them on hold without any food to get by on. They do not die in the refrig. just slow down a bit.
So, by allowing them to eat a little as suggested by DocDough, they have enough food to hold them over for the long haul when you can come back and 'rescue' them.
If you were going to use the starter the following day - allowing it to ripen all the way wouldn't make as big of a difference since it would only be stored overnight.
Hope this helps.
Thank you for the advice. I just want to make sure I keep this monster alive! I can't complain though about the added bonus of SD pancakes with the discarded starter.
After reading Mini's guidance I went back to the spreadsheet and got real numbers from the model, and 1:5:5 will be plenty for 10 days at 2°C. The issue with growth at refrigerator temperatures is that the ratio of LAB growth to yeast growth is huge. The LAB is capable of multiplying up to 24X in 10 days while the yeast can only grow by a factor of ~2.3X. At 1:5:5 the LAB will stop growing after a few days simply because the pH gets too low for it to reproduce, but the yeast (becaues it is insensitive to pH and has plenty of food) will be able to continue multiplying for much longer (thus the need to rebalance the populations with a few refresh cycles at room temperature when you get home). Because of the acid buildup during extended refrigeration (the LAB continues to produce acid long after it has stopped reproducing) it is important to refresh at a fairly high ratio when you get home just to get the pH above ~5 in the post-refresh mixture which allows the LAB do actually grow some. My rule of thumb is to always go with a minimum of 1:2:2 and preferably 1:5:5 or 1:10:10 when I get home from a trip (depending on time of day - and always feeding it again just before going to bed).
A ratio question. I work with 100% freshly ground whole grains so I mix my leavens at 65 -75% HL to keep less sour.
Does the HL need to be at 100% or can I do this at 65-75% HL?
Within some reasonable bounds hydration is not a significant factor. You are (at 65%) in bounds.
Thanks for letting me know. I would be interested in reading the info. you mentioned above too if it is available on-line anywhere.
Though I have read a lot....a lot still gets past me as there is so much to digest.
Regarding feeding, have been feeding my starter 3 times a day because it peaks in 4 hours and then starts to decline. Is the decline ok?
Your starter (at 100% hydration) will approximately double before it starts to decline irrespective of the refresh ratio, it just takes longer at higher ratios. In the summer when the kitchen is at 25°C or so most of the time I generally refresh twice a day at about 1:14:14 (range is between 1:2:2 and 1:30:30) but the inter-refresh time is not always 12 hrs because of temperature or schedule conflicts, and sometimes I accidently forget to feed it at night so it goes well past peak before it gets fed again. For home bakers I don't think timing makes much difference within a few hours assuming you occasionally do let it go too long and the LAB:yeast ratio has a chance to reach its natural end state (wide variety here) of 100:1 . Starter is amazingly tolerant of single event mistreatment; however it does adapt if you change the refreshment timing and ratio for an extended period.
I saw in your comment earlier that you looked at a spread sheet.. do you mind sharing. I love having the in-depth knowledge behind a subject because, for me, it builds a better foundation and helps me improve faster.
I was reading this post and had a question. The 1:5:5 figures, what does that mea? Sorry to ask for clarification I'm still new at sourdough starters so I'm just trying to learn. Thanks..
It is 1 part starter to 5 parts water and 5 parts flour. You want equal weight with the water and flour for 100% hydration.