This tutorial was conceived in 2 parts.
- Part one shows how to make a yeast starter.
There are a couple different ways to can and preserve your starter wort.
Method 1: ...Is to use a pressure cooker. The key is setting the pressure to 15 psi which causes the wort to boil at 250˚F (121˚C) instead of the 212˚F (100˚C) which is standard boiling temperatures. The higher temperature is hot enough to kill Clostridium Botulinum in a reasonable amount of time.
Method 2: ...Is what I detail in this video. The boiling water method is presented here because it has been used successfully for many years,
- But be aware, this method does allow for the minute possibility of botulinum poisoning. Although the probability of this is extremely low, the consequences can be severe if it does occur.
In this tutorial, I will be walking you through the steps of canning/preserving a (yeast) starter wort.
"Why would I want to do this?" You may be asking yourself. The answer is simple.
Have you ever had a scheduled brew day, let's say tomorrow (or this weekend) but you still haven't gotten your yeast starter going? Then you say to yourself, "Ugh! Prepping a starter is going to take me 2 hours." Which is time most people don't have (or want to take) to produce such a small thing.
But what if you could get multiple batches worth of starter taken car of all at once; multiple brew-day's worth?
THAT is why you would want to can and preserve it.
Here are the simple steps to canning and preserving your starter wort.
- After making your starter wort, keep it hot.
- Take all of the mason jars that you need and boil them in a hard rolling boil for 10 minutes (at altitudes of less that 1,000ft).
- Boil an additional 1 min for each additional 1,000 ft of elevation.
- NOTE: http://www.healthycanning.com/sterilizing-canning-lids-jars/ Ball recommends NOT boiling the lids for any canning times of more than 10 minutes. Just make sure they are cleaned immediately prior to using.
- If you choose, let them soak in StarSan after cleaning.
- TIP: Keep the jars full of the hot water until you are ready to fill with wort.
- TIP: Retain the hot water for the next step but do not continue boiling the water.
- After a while, you will begin hear "Dink!" "Dink!" This is the jar pressurizing (like jelly jars at the store).
- You'll notice the little button on the lid is now pressed down. This is a good thing.
You can do as large a volume of Wort as you choose. Just understand that you will have to repeat the steps above for each additional volume of wort.
I feel obligated to post the following warning, just as a precaution, even though, BALL says this is highly unlikely as long as you use common sense cleaning and sanitizing methods before hand.
BYO states… http://byo.com/stories/issue/item/434-canning-yeast-starters
In home food preservation, foods are divided into “high-acid” foods, with a pH below 4.6, and “low-acid” foods, with a pH above 4.6. High-acid foods can be safely canned using the boiling water method. It is recommended that low acid foods be canned in a pressure cooker, where the increased pressure means that water boils at 240 °F (116 °C) or higher. The pH of boiled, unfermented wort is around 5.0–5.2, making it a low-acid liquid.
The reason for the high-acid/low-acid distinction is that spores of the bacterium Clostridium botulinum can survive in low-acid foods, even if they have been heated to 212 °F (100 °C). Clostridium botulinum produces 7 different classes of botulinum toxin, labeled A through G, and all are powerful neurotoxins. Botulinum type A, the most toxic, is 15,000 times more potent than VX nerve gas.
Botulinum toxins stop impulses in the nervous system from triggering muscular contractions. Symptoms of botulism usually arise 24–36 hours after exposure to the toxin and include dry mouth, weakness, double vision, vomiting, depressed breathing and a progressively intensifying paralysis leading to death.
The presence of Clostridium spores in raw honey is why doctors recommend not feeding it to infants or small children.
Although spores of the bacteria are found almost everywhere, cases of botulism are actually relatively rare. Most years, around 110 cases are reported in the US, with most occurring in infants or small children that have eaten honey or other affected foods. On average, less than 30 cases per year result from improper home canning.
In fermented wort (i.e. beer), the alcohol content, low pH (4.0–4.4) and anti-bacterial components in hops prevent C. botulinum from surviving. In preserved, unfermented, lightly-hopped wort, it is possible for the bacteria to grow. Although the bacteria will die if the wort is fermented, any toxins produced by the bacteria will not be neutralized.
To minimize the possibility of botulinum poisoning, can your starter wort using a pressure cooker or add acid — such as phosphoric or lactic acid — to your starter wort such that its pH is 4.6 or below if you are using the boiling water method. (High hopping levels alone are likely not enough.)
The boiling water method is presented here because it has been used successfully for many years, but it does allow for the possibility of botulinum poisoning. Although the probability of this is low, the consequences can be severe if it does occur.