yeast ranching

1. Yeast Ranching Eric Oettinger February 10, 2008

3. Canned WortCanned wort will save hours and lasts years. 1 gallon wort (1.030-1.040) second running – or – 1 gallon water + 3 cups DME 1 oz hops ¼ tsp Irish moss ½ tsp yeast nutrient ½ tsp yeast energizer Boil wort, hops, and Irish moss 15 minutes Add yeast nutrient and energizer Quarts: Ladle into 4 quart jars, filling to about 1" from top. Place canning lids on jars and lightly hand tighten rings. Bring to boil hot water bath canner with 2" of water then cover and boil for 45 minutes. Pints: Ladle into 8 pint jars, filling about 1" from top. Place canning lids on jars and lightly hand tighten rings. In pressure cooker add water to bottom of jars and heat. When pressure is reached, cook 25 minutes.

4. Agar Slants and Plates 1 cup canned wort (Pressure cooked pint will be clearer than boiled quart. Use remaining wort for start tubes.) 1 Tbls agar Pour wort in small saucepan. Sprinkle agar over wort. Wait 1 - 2 minutes for agar to dissolve. Heat to boiling . Stir constantly 5 minutes. From here work quickly, the agar will harden if it cools below about 100 degrees. Slants: Use a syringe to fill each test tube with 5 ml agar mix (about 1/3 full). Lightly tighten caps. Autoclave 15 minutes at 250 or pressure cook 25 minutes. After pressure escapes and before the tubes cool below 100, use tongs to remove tubes and place at a very shallow angle (lean them on a pencil). When completely cool, fully tighten caps. Store anywhere. Plates: First clean plates using 90% isopropyl. Use a syringe to add 15 ml agar to each. Quickly seal with electrical tape. Cool. When cooled store with agar side up so that any condensation forms on the lid, not on the agar. If nothing starts growing in three days, keep plates in a plastic bag in the refrigerator. Remaining 1/2 cup of canned wort can be used for starter tubes. 5 ml wort. Sterilize as slants. Allow to cool. Tighten caps. Store anywhere.

5. Streaking Sending yeast via USPS: A dab of trub on a square inch of paper towel, then folded in aluminum foil can be sent in an envelope to a homebrewing friend. Smear the paper towel on plate when received. Reculturing from a bottle with active yeast: Pour off all beer leaving all sediment in the bottle. Drink beer. Add 5-10 ml wort to bottle. Add airlock. Wait 2 days. Use loop to streak after stirring up the sediment. (note that many breweries, including most Belgians, use different strains for fermenting and bottle conditioning.)

6. Ranch Maintenance Re-propagate annually. Try to find an area free from drafts and dust (and kids and pets if possible…). Sterilize work area by wiping surfaces with alcohol. Sterilize: loop and caps of both old and new test tubes using either alcohol or a flame immediately before transfer. Be careful with alcohol near a flame! Use loop to sample. Spread over fresh slant. Wait 3-4 days to ensure that yeast is growing (and nothing else). Return ranch to refrigerator. (DO NOT FREEZE!)

7. Beginning Ranching Collect from batches as you brew. Purists may want to streak from the bottom of the smack pack to pick a single colony; I’ve had no problems directly inoculating slants by dipping the sterilized loop into what’s left at the bottom. Share slants with friends. Recondition from bottles (commercial or homebrew). Blended smack-packs are likely to be dominated by one strain.

8. Procedure For a Starter(appropriate for 5 gallons of 1.060 beer) Using a loop, inoculate 5ml wort with yeast. Wait 2 days. Bump 5 ml to 50 ml in 1L flask. Wait 2 days. This 50 ml volume is now comparable to a smack-pack. Bump 50 ml to 500 ml. Wait 2 days. Pitch. Or, optionally, refrigerate for 1-10 days, decant, pitch. Or, optionally, bump volume further to make a larger starter for lagers or higher gravity ales ?. Or, optionally, after decanting, restart a day before brewing with more wort to reduce lag time. Note that using a magnetic stir plate and / or oxygenating the wort will improve cell counts.

9. Sources Most LHBS’s don’t like yeast ranching. Wally sells almost nothing; Midwest and Northern Brewer sell only what’s useful for making starters. www.thegrape.net test tubes ($0.69 each or $49 per 100) inoculating loop ($3.99) www.morebeer.com flask 1L ($9.95) agar – 2 oz. ($8.50) Petri dishes – 25 disposable ($9.95)

10. More Resources Books: Two that are available: “The Fungus Among Us” -C.White “First Steps in Yeast Culture” –P.Rajotte Web: These are some I bookmarked http://www.bodensatz.com/staticpages/index.php?page=yeast-culture-FAQ http://www.brewingtechniques.com/library/backissues/issue2.3/king.html http://byo.com/feature/810.html http://www.fortunecity.com/littleitaly/giotto/175/learn.htm http://www.wyeastlab.com/ http://www.whitelabs.com/ http://realbeer.com/spencer/yeast-culturing.html