LADistiller

Changing pH of wash

29 posts in this topic

You're right, yes, that would count as pasteurization.

But in terms of what heating our mash does -- certain strains of bacteria can survive temperatures up to 70-80 degrees. Certain strains of clostridium can even survive boiling, which creates a challenge for large scale food preservation - canned foods are heated by pressurized steam to 120+ degrees Celsius!

Since most of us are heating to only 63-67c, many strains of lactobacillus survive and will gradually take over the mash, working anaerobically on it, as the fermentation winds down and yeast autolyzes into nutrients.

This is, of course, ideal - lactobacillus is essential to the character of a developing whisky as it ages. They produce lactic acid itself, and many other compounds which are desirable flavor precursors. We just don't want them metabolizing citric acid.

Share this post


Link to post
Share on other sites

Hitting 140f for 45-60 minutes will kill most but not all bacteria. It's how the sous vide guys can safely cook food for long periods at lower temps. Most of us mash for at least an hour at that temp,  Hitting 145 reduces the time down to 30-45 minutes. 

http://www.foodhandler.com/cooking-pasteurizing-safer-foods/

MDH - I didn't know malic acid would encourage lactic acid production. Thanks very much for that.

 

Share this post


Link to post
Share on other sites

Oh I gotcha, I think this is the classic car of pasteurized v sterilized.  

Follow up question, given lactic acids positive contribution to mouthfeel, do you foresee distilleries intentionally bringing in a malo-lactic ferment into the program? (Idk enough about wine to know how long that step normally takes)...or am I completely off base?

Share this post


Link to post
Share on other sites

We use malic acid to acidify high pH fruit mashes and also whiskey mash when we don't have backset. In wine and cider, MLF is typically started at the end of primary fermentation when brix readings near zero. With the general instability of most whiskey and non-grape fruit mashes, I think you would have other problems if you were waiting for bacteria to convert the malic acid you added into lactic. It would make more sense to add the lactic acid yourself at the acidifying stage. I couldn't say for whiskey, but MLF is thought to have an impact on brandy distillate quality (something my experience with distilling wine and cider generally supports).

58f3fc87d4b91_MLFindistilling.png.305daaf1ff7f10d8fc6c363bdb1e505e.png

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now