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Yeast starter boil-off?

Hello I know this was probably asked before. But when doing yeast starter’s should one take into account small amount of evaporation when boiling there starter’s. Meaning let say I am doing a 1L starter would one want to boil 1.1L to 1.2L or 1100mL or 1200mL of water so they end up with about 1L they are shooting for?

You would compensate for boil off to have a full liter of water to add the DME or LME to. Less than a liter may increase the specific gravity over the optimum of 1.037 to 1.040. You don’t really need to boil the water too long. I just bring the water to a boil and then turn the heat down so the water simmers for a three or four minutes. This is to sanitize my kettle. A long hard boil won’t improve the starter wort.

I bring the water to a boil, move it off the heat, stir in the DME, put it on the heat for maybe a minute while stirring just to make sure all the DME is mixxed in, then take it to the sink to chill.

I do boil the water for 5 min. Than add the dme. Boil for a other 5 min. Stir make sure all the wort. Disolved. No clumps. Add them to the flask. And cool with ice in the sink. Add the yeast once cooled down and let it on the shake plate for 30 hours

I often wondered if we shouldn’t be creating a starter wort of the same gravity as the OG of the wort we will be pitching it to, but I’ve never had any problems. NB’s instructions are to add 1300 ml of water for a 1 L starter wort and boil for 15 minutes. I have followed these instructions because I feel more confident as to the sterility of the starter wort, but I see no reason why you couldn’t reduce your initial volume and boil a shorter duration.

No. The generally accepted best practice is to create a starter wort around 1.035. You’re not making beer. You’re giving the yeast the chance to reproduce. They need fuel to do so but not enough to over work them.

There’s really no need for all that boiling. All you need to do is bring the water to a boil to kill off any water born bacteria. Boiling temp for a few seconds will kill anything and sanitize your kettle. Of course this has been discussed many many times here and everyone has to be comfortable with their own MO.


I used to boil the starter wort for 15 minutes because that was the accepted method but it is a waste of time. As said just bring it to a boil and you won’t lose enough to worry about it.

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No, you don’t want to do that unless the OG is very low. The purpose of a starter is to grow healthy yeast and that hapens better in lower gravities. 1.036 is about ideal.

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