What the toast?

I went out picking blackberries today for my blackberry melomel. I only needed 8 lbs, but ended up with 16 lbs of berries! I was thinking of using the last 8 lbs for making maybe a gallon of blackberry wine, and I found this strange recipe:

http://www.crystalforest3.homestead.com/recipeBlackberryWine.html

1 gal. Blackberries
1 gal. Spring water, lukewarm
5 lbs. sugar
2 slices toast
1 pkg yeast

In a very large wide-mouthed container, crush the berries and add water. Mix in half of the sugar and stir until dissolved. Float toast on top and sprinkle with yeast. Cover container with cheesecloth and let stand for 5 days. Add remaining sugar and leave for another 2 days. Stir well. Let the mixture sit undisturbed for 3 more weeks. Strain through cheesecloth to remove seeds from wine. Bottle and serve when desired.

TOAST? It says to add two slices of toast to the must! I've never made wine before, and it was more of an experiment with excess free fruit, but TOAST? This can't be a real recipe can it?

Maybe it's a breakfast wine.
Buttered side up or down?
But seriously, tho, I have no idea.

Maybe food for the yeast? Just about all berry & fruit wines require yeast nutrient.

I've got two gallons of blackberry wine chugging. It's amazing the amount of crud it generates. This is from last year's crop, but I'll probably kill the yeast and add some juice from this year's for sweetness. My berries are starting to come in at the bottom of the hill, but up by the house they are still little green things.