Way back in the day I made a full 5 gallon batch of pilsner malt wort and pressure canned it to use for starters. Of course it had a great pilsner color out of the tun, and it was boiled for a while as well. I remember canning such a large batch was a bit of a chore and the wort was notably darker after canning. I used it for many batches and then eventually lost the jars in boxes in the garage. Well while preparing for a Yard Sale I found the remaining jars. The wort now appeared to be a porter from Maillard Reactions. The seal on all the lids was still intact and even the trub in the bottom of the jar was brown. Unfortunately no photos were taken.
As the wort was discarded down the drain I feared I was going to have to scrub the mason jars to get them clean. I brushed enough to get the large accumulation of sediment off the bottom and put them in the dishwasher. After a single cycle everything was sparkling clean.
I’m thinking when I start brewing at the new house I might make an extra gallon or so of wort and pressure can it for starters. Making an entire batch is too much work and too many jars. At least I know my process way back when was sound. My best guess is that batch of wort was made over 20 years ago.
This might work as long as you’re killing the botulism spores by boiling under pressure above 240 F. Without that I’d be concerned about saving the wort for any prolonged period as the pH of wort is too high, allowing botulism to take hold, which is very dangerous and in some cases can kill you.
Kind of interesting though that a pilsner wort darkens so much with oxidation and/or age.
My pressure canner holds 7 quart jars per batch and I will make and can 1 to 1.5 gallons at a time which is plenty enough to last several months with my brewing schedule. I find myself making and canning 1 batch of wort maybe twice a year which is less work and leads to less waste.
making a starter is a slight annoyance but tbh ive had really good results with minimal effort:
-1 litre water set aside ahead of time for 24 hours
-add 100g DME to water in a small pot and boil for 10 mins
-cool a bit and pour into a 1 gallon glass carboy.
-add yeast when its cool and shake it around a lot
Sounds like the shaken not stirred method. The shaking should happen before you add the yeast to avoid shear stress which is detrimental to yeast cell wall health.
Pressure canning a single set of jars would be a cinch and is likely what I will do the next time I brew. Think of it as 15 minutes every time for a starter or pressure canning off to the side while I boil and cool the wort so really no additional time.