Add 1/2 cup water to each, grapes and sugar, separately.
Boil grapes for 3-4 minutes, or till soft. Cool.
Boil sugar, water till a drop pressed between fingers feels sticky (1 thread consistency) Blend grapes till smooth, sieve.
Add to sugar syrup, boil and simmer further for 5 minutes.
Cool very well.
Just before serving, blend grape concentrate and milk till frothy.
Pour into transparent glasses.
Top with a scoop of vanilla or black currant icecream if desired.
Serve immediately.
Making time: 30 minutes
Makes: 3 med. glasses
Shelflife:
grape concentrate: 2-3 days refrigerated
milk shake: best fresh