Why do people boil DME?

[Tom Archer.]

As a newbie, I'm looking and learning, and some things seem odd.

- DME is manufactured by boiling and spray drying wort. The powder is very readily soluble.

- It seems widely accepted that bacteria don't survive above 165F/75C

But every video on YouTube and every book description of making a starter refers to dissolving the DME and then boiling it, which in a conical flask seems to readily invite boil over.

Why not just dissolve the DME in a pan at around 80C, and then dump it into a sanitised flask? Less electricity, less potential mess..

..but as no-one seems to recommend this, is there a reason?

 

[foxy]

As a newbie, I'm looking and learning, and some things seem odd.

- DME is manufactured by boiling and spray drying wort. The powder is very readily soluble.

- It seems widely accepted that bacteria don't survive above 165F/75C

But every video on YouTube and every book description of making a starter refers to dissolving the DME and then boiling it, which in a conical flask seems to readily invite boil over.

Why not just dissolve the DME in a pan at around 80C, and then dump it into a sanitised flask? Less electricity, less potential mess..

..but as no-one seems to recommend this, is there a reason?

Could be because of the sugar content, if you want to locate wild yeast the kitchen is the best place to start. Everything needs sugar to survive. I do know that at 80C honey takes 30 minutes to be pasteurised.

 

[Pennine]

I don't boil dme for starters but do get it to 80c and then cool. You can technically keep it at lower temps but for longer time.

 

[Sadfield]

If you view the brewing process as Mash>Boil>Ferment. A hopped beer kit places the brewer after the boil stage. Unhopped Malt Extract places the brewer after the mash stage. That's why you generally see brewers boiling malt extract. It may not necessarily have been boiled during manufacture. This graphic suggests that Muntons don't boil prior to evaporation with LME.



IF DME is boiled it may not have been done long enough to drive of many of the off flavour causing volatiles. Which you might it want to add when pitching the yeast.

In a starter though it matters less. Adding a small quantity of hops to a starter prevents boil over.

 

[clib]

I always boil starter wort in a flask and cool it and then pitch yeast into that. Gives me peace of mind. Minimise the chance of infection. Wort and flask both get the heat treatment. I only have one flask though so occasionally I sterilise a jar or two and transfer boiled wort to them, on the rare occasions when i am culturing up more than one yeast.