Another Starter - Too much boil off? Will it work?

Third starter I've done. Previous 2 were 1/2 liter water, 1/2 cup dme. as recommended by the extract kit...

According to MrMalty for my 1.048ish moose drool all grain clone I need 1.5l starter!

The actual clone calls for a 750ml starter, so I did that. 750ml water, 3/4 cup DME. Boiled 10 minutes added nutrient boiled 5-7 more. Cooled and put in a flask with 1 vial WPL005. Total came out to barely 425ml....

So I boiled off over 300ml or 1 third of my starter in 15min? wow.

Will this 425ml starter handle it? It's bigger then my previous 2 starters and they made an oatmeal stout and a English brown just fine...

Also, was hoping to get it in the fridge Friday night so I can decant sat and pitch. Should 24 hours give it enough time or should I skip the decant with such a small starter and just pitch it sat?

I think that ideally you should dilute the starter - 3/4 C. of DME in 425mL gives you a gravity somewhere around 1.090, which is way too high for starter wort. Anything over 1.050-1.060 is stressful for yeast and ideally starter wort should be between 1.030 and 1.040. I would recommend adding ~800mL of boiled and cooled water, skip the chilling and decanting and pitch the entire volume.

Oh I didn't even think about yeast stress! Going to boil some water right now.....

Ok boiled another 800ml of water, but only for like 5 minutes, hope that was long enough. Cooled it like wort and added it when it was 75 degrees. Swirled it up and it is bubbling away this morning.

It is a good liter+ now, can't believe how small my other starters were in comparison. This could have been why my English Brown Ale came out with some off flavors.

Nervous about this much sour starter effecting the beer though, only a 5g batch.

Sounds good. You're definitely better off having lots of healthy yeast with a bit of spent starter wort than little yeast and no spent starter. For most of my beers I make ~2 quart starters from pressure-canned wort from previous batches (when I'm not repitching slurry) and then pitch the whole thing at high kraeusen.

Just a thought, but when the recipe is giving you a starter size I would assume that is pretty vague. The recipe may be assuming you have a stir plate. They have no idea for your methods of making the starter (if you have a stir plate or not). With Mr Malty you can customize it to your methods, so I'm thinking I would go with Mr Malty.

+1 to BryceL

Never trust a recipe, always follow Mr Malty

Thanks all. Good to know definitely go by MrMalty. She's bubblin like mad, so hopefully I the 2nd all grain goes good tomorrow and I can pitch that thing here in 16 hours....

I did something similar with my very first starter last night...I had a 1L starter for a 1.064 beer, but enough boiled off/boiled over that I ended with roughly .5L. Is it too late at this point to add some boiled/cooled water to dilute the starter wort?

Nope, not too late. I would definitely dilute.

Awesome. Going to boil & add .5L of water. Thanks for your help.