Using The Kettle Trub

[MHB]

Same enzyme (invertase) will attack Maltose or Sucrose, the idea that yeast needs the help was a 70's thing came came and went, frankly the inverting part of the exercise is of little or no benefit to the yeast, it doesn't need the help.

Different story when you are trying to make candy, as mentioned true "Caramelisation" (sugar sugar joining) temperatures are very high, add some water and acid or other catalyst and and it gets a lot easier. One important point to remember is that homemade invert is only about 25% inverted, the rest is the same stuff you started with. Commercial Syrups may get as high as 65% inverted in the case of Golden Syrup, but most of them are around 40-45% inverted. Another reason invert is still made is that the syrup doesn't recrystallise as readily, so it stays liquid and can be pumped conveniently (important info that, if you ever buy a mega brewery).

That doesn't speak to the flavours that develop as sugars caramelise, and having used most of the Belgian Candy Sugars and Syrups available I am quite familiar with the flavours, and think they work really well in Belgian beers. Both Golden Syrup and Treacle are examples of commercially made invert and I have a high opinion of them on crumpets, but not in most beers.

M

 

[Thirsty Boy]

I like the idea of turning wort from trub into candy sugar... and I'm not so sure you cant filter out the bad stuff. I was doing the "filter trub - use the wort for a starter" thing till I got my new kettle going (not enough wasted wort to bother now) and if you put in a little effort and are patient you get very clean wort at the end.

I would

-Use a small colander and a teatowel
-Pour in the trub filled wort
-It will go fast for a while but the filtrate will be cloudy
as a layer of gunk builds up on the towel - the rate of filtration slows down and the wort becomes bright
-When the wort is running clear (dripping by now really) - re-introduce the cloudy wort that has previously run through to the top.. pour it on a spoon/ladle so as not to disturb the layer of filtering gunk
-Go and watch telly for at least a few hours
-Use the filtered and very bright wort however you see fit. Mostly I dilute to 1.040 and reboil for starters.

I concur with the whole inversion thing being a waste of time for feeding yeast - they are most happy doing it themselves. It wont hurt, but it wont help much either.

 

[felten]

I had heard (I think on brewstrong) that yeast can't eat maltose if they're producing invertase to eat sucrose. But having said that, it doesn't seem to be a problem.. maybe it would be with a higher percentage of sucrose, or if the yeast died off due to high alcohol/time before they got to the maltose?

 

[Thirsty Boy]

Yeast wont eat maltose when there is more than 1% w/v glucose in a wort. Inversion of sucrose happens outside of the cell... so at the end of the day, to a yeast cell, sucrose is just glucose and fructose.

 

[Bribie G]

Yeast wont eat maltose when there is more than 1% w/v glucose in a wort. Inversion of sucrose happens outside of the cell... so at the end of the day, to a yeast cell, sucrose is just glucose and fructose.

About a hundred years ago in British Breweries there was a process called "Tompson's process" for inverting sugar. They would :

The yeast process (Tompson's), which makes use of the inverting power of one of the enzymes (invertase) contained in ordinary yeast, is interesting. The cane sugar solution is pitched with yeast at about 55 C., and at this comparatively high temperature the inversion proceeds rapidly, and fermentation is practically impossible. When this operation is completed, the whole liquid (including the yeast) is run into the boiling contents of the copper. This method is more suited to the preparation of invert in the brewery itself than the acid process, which is almost exclusively used in special sugar works

The extra yeast into the kettle would probably do no harm either, like the current home brewers who boil up a couple of old kit yeasts and chuck them in.