During the almost two years I have maintained a sourdough starter, yes, I have frozen it once or twice a year when I was away for more than a week and, off premises, for Passover. No, I have not gotten up the nerve to ask someone to feed it while I am on vacation or visiting elsewhere. It's like admitting I am as attached to the starter as I am to my dog or the plants I have managed not to kill, a minor miracle. I didn't know why I froze it because it took as much time and effort to resume the starter's liveliness as it would to create a new starter.
Asked the experts
Freezing does not work well. The starter takes as long to revive as it would to create a new one. Knowing there has to be a better way, I went to the experts, the participants on the sourdough and starter forum of the Fresh Loaf and on the Sourdough Companion forum. Not exactly a new topic. A little research at either of those venues supplied words of wisdom and plenty of opinions.
My own little science experiment
Here are the suggestions.
1. Before going out of town, dry starter on parchment paper by spreading it thin. The starter dried overnight. Put parchment paper in a plastic bag. Can refrigerate or not once dry. Most say no to necessity of refrigeration. Upon return, mix dried flakes with equal amounts of water and flour, about 3 ounces or 90 grams of each (though that seems excessive to me). [Photo: Experiment contestants posing on the kitchen counter.]
2. Feed the starter normally before leaving and put it in the refrigerator for up to three weeks. Well, the person said two to three weeks, so I should test this one a few times. The starter should be nice and bubbly after a couple of feeds.
3. Get the starter nice and firm before abandoning it for a vacation; then refrigerate for up to three months. The person recommended a 66 percent hydration, which for normal people translates into - going simply with the math - 100 grams of flour and 66 grams of water. This person just makes a batch of this stiff starter and uses it out of the fridge. Rye was suggested, but I might try this with all purpose flour.
4. Same as #3, but with 50 percent hydration, which is super stiff I imagine. That would be 100 grams of flour to 50 grams of water. But this person took the starter along for the extended travel and fed it every day. That is not happening here. Not trying this one. Let's see what happens first with the 65 percent hydration experiment.
So far ...
Parchment paper - Spread the starter on parchment paper and it was dry by the next morning. Put the parchment paper in a plastic ziploc bag and placed it in a cool, dry place - a safe place - my bread baking drawer. That was Oct. 23, 2014. Leaving for three weeks before attempt to resuscitate.
65 percent hydration - Took about 15 grams of my starter, used a calculator to figure out the amounts for making a small 65 percent hydration starter. Totally stiff. Placed the small jar in the back of the fridge. That was Oct. 22, 2014. Will take out the jar in three weeks.
Regular Starter - Put a wee bit of starter in a jar, fed it as normal and placed that jar in the back of the refrigerator. Will inspect in two weeks. Somewhat afraid of how disgusting it will look and smell two and three weeks out.
Rye Starter - Just because I had extra rye start after making bread #58, a spelt/rye bread, I decided to add this starter to the experiment. This particular starter was made up of three parts water to two parts rye flour, or, translated into hydration percentage terms, 150 percent hydration.