I've been using a starter for some years now and have always been under
the impression that a teaspoon of sugar was sufficient to feed it after
a period of non-use. When replenishing the starter, I've always used
water, flour and sugar.

After a long period of non-use and neglect, I found my starter in poor
shape, came here and found the FAQs. I've used the instructions there
to proof my starter, and it seems to be healthy again.

Is there any situation that would call for using sugar to feed or
replenish a starter? I'm not sure where I got the recipe that I've
used, and the starter stayed usable for my purposes although it did
often get a layer of "hooch" after periods of neglect in the
refrigerator.

I found that there is no reason what so ever to use suger niether in
the starter nor the dough when making sourdough.
One of my starters was neglected in the fridge for about 4 months, the
whole thing froze and became dry as a rock. i was able to scarpe
something like half a gram of "wet" starter from it, fed it 50g water
50g flour and 12 hours later it was alive and kicking!
I guess the little critters love life the same way we humans love it
:-) survivle of the fittess...

Amit b

Diastatic malt is much better than sucrose( or table sugar) in
enlivening the starter activity. supposing your starter behavior
appears sluggish.....
BTW,Just a week ago I was in an artisan bakery who was making sourdough
and his version is to spike his starter with toasted wheat germ,just
about 100-200 grams wheat germ per 10 kg of refreshing flour weight).

Indeed it resulted in vigorous fermenting starter which the baker
claimed to shorten the final proofing time by about half and hour.
Technically ,,,, It is likely that the nutrients in the wheat germ
(that leached out into the starter mash) could have invigorated his
starter critters.
His system of refreshing starter was to add flour with little wheat
germ and water( room temperature) to the starter at the ratio of
1/1/1.2 starter/flour / water respectively allow it to ferment at room
temp for 8 hours place it in the cold room for next 4 hours then stir
it ( about half a minute),.let it stand further for 12 hours .
Meaning he only refresh his starter once a day.

Roy