Technically, yes, the cells in an older culture benefit from lower osmotic pressure. However, there is a tradeoff in that a lower gravity starter has less carbon available for growth; therefore, starting with a lower gravity often means stepping the starter. A four month old White Labs culture is not that old in the grand scheme of things; therefore, I would not sweat it.
Summer favorites that I don’t think I can do with dry yeast are hefewiezen, (Wyeast 3068) Patersbier (Wyeast 3787) and belgian wits (Wyeast 3944)
Wyeast 3068 is easy. That’s W-68, which is available in dry form as Fermentis Safbrew WB-06. The other two are not as easy to substitute. Luckily, I am not a fan of phenolic yeast strains.
If S-04 works out, I may just save those other beers for when I can get to the LHBS, or just order them online before it gets warm and wake them up with a good starter.
Been wondering about experimenting with British yeast in a beer aiming to be a summer quencher…looks like I’m getting steered down that path.
I sometimes get surprised by the heat tolerance of liquid yeasts.
I have twice received oversea shipping of Wyeast smackpacs ( a Wit yeast and a Burton-ish strain) without cooling, and I have not noticed any problems. Pitched it without a starter in two 2.5g batches.
Some weeks ago, i forgot two White Labs (Brett Brux Trois Vrai. and Belgian Saison III )vials in room temperature for a week after traveling with them in my backpack at 80f. Both of them were alive and kicking. I put them in the refrigerator and made a starter before I used them. 